DIVALPROEX: 11,461 Adverse Event Reports & Safety Profile

Divalproex sodium is a stable co-ordination compound comprised of sodium valproate and valproic acid in a 1:1 molar relationship. Chemically it is designated as sodium hydrogen bis(2-propylpentanoate). Divalproex sodium has the following structure: Divalproex sodium USP occurs as a white crystalline powder with a characteristic odor. Divalproex sodium delayed-release tablets, USP are for oral administration. Divalproex sodium delayed-release tablets, USP are supplied in three dosage strengths containing divalproex sodium USP equivalent to 125 mg, 250 mg, or 500 mg of valproic acid.

Inactive Ingredients

Divalproex sodium delayed-release tablets, USP: silicon dioxide, microcrystalline cellulose, croscarmellose sodium, povidone (Kollidon 30), hydroxypropyl cellulose low substituted, talc, methacrylic acid and ethyl acrylate copolymer dispersion, and diethyl phthalate. In addition, 125 mg tablets are coated with opadry clear 04K59023 and opadry II complete film coating system 86G540000 pink. Opadry clear 04K59023 contains hypromellose and triacetin, opadry II complete film coating system 86G540000 pink contains polyvinyl alcohol, talc, titanium dioxide, macrogol/PEG 3350, FD&C Red #40, lecithin (soya), and vanillin. 250 mg tablets are coated with opadry clear 04K59023 and opadry II 86G53866 orange. Opadry clear 04K59023 contains hypromellose and triacetin, opadry II 86G53866 orange contains polyvinyl alcohol, talc, titanium dioxide, macrogol/PEG 3350, lecithin (soya), vanillin, FD&C Yellow #6, and iron oxide yellow. 500 mg tablets are coated with opadry clear 04K59023 and opadry II 86G84795 pink. Opadry clear 04K59023 contains hypromellose and triacetin, opadry II 86G84795 pink contains polyvinyl alcohol, talc, titanium dioxide, macrogol/PEG 3350, lecithin (soya), FD&C Red #40, vanillin, and FD&C Blue #2. The tablets are printed with opacode black S-1-17823 containing shellac glaze in ethanol, isopropyl alcohol, iron oxide black, N-butyl alcohol, propylene glycol, and ammonium hydroxide.

Chemical

Structure

AND USAGE Divalproex sodium extended-release tablets are indicated for:

• Acute treatment of manic or mixed episodes associated with bipolar disorder, with or without psychotic features ( 1.1 )
• Monotherapy and adjunctive therapy of complex partial seizures and simple and complex absence seizures; adjunctive therapy in patients with multiple seizure types that include absence seizures ( 1.2 )
• Prophylaxis of migraine headaches ( 1.3 )

1.1 Mania Divalproex sodium extended-release tablets are a valproate and are indicated for the treatment of acute manic or mixed episodes associated with bipolar disorder, with or without psychotic features. A manic episode is a distinct period of abnormally and persistently elevated, expansive, or irritable mood. Typical symptoms of mania include pressure of speech, motor hyperactivity, reduced need for sleep, flight of ideas, grandiosity, poor judgment, aggressiveness, and possible hostility. A mixed episode is characterized by the criteria for a manic episode in conjunction with those for a major depressive episode (depressed mood, loss of interest or pleasure in nearly all activities). The efficacy of divalproex sodium extended-release tablets is based in part on studies of divalproex sodium delayed-release tablets in this indication, and was confirmed in a 3-week trial with patients meeting DSM-IV TR criteria for bipolar I disorder, manic or mixed type, who were hospitalized for acute mania <span class="opacity-50 text-xs">[see Clinical Studies ( 14.1 )]</span>. The effectiveness of valproate for long-term use in mania, i.e., more than 3 weeks, has not been demonstrated in controlled clinical trials. Therefore, healthcare providers who elect to use divalproex sodium extended-release tablets for extended periods should continually reevaluate the long-term risk-benefits of the drug for the individual patient.

1.2 Epilepsy Divalproex sodium extended-release tablets are indicated as monotherapy and adjunctive therapy in the treatment of adult patients and pediatric patients down to the age of 10 years with complex partial seizures that occur either in isolation or in association with other types of seizures. Divalproex sodium extended-release tablets are also indicated for use as sole and adjunctive therapy in the treatment of simple and complex absence seizures in adults and children 10 years of age or older, and adjunctively in adults and children 10 years of age or older with multiple seizure types that include absence seizures. Simple absence is defined as very brief clouding of the sensorium or loss of consciousness accompanied by certain generalized epileptic discharges without other detectable clinical signs. Complex absence is the term used when other signs are also present.

1.3 Migraine Divalproex sodium extended-release tablets are indicated for prophylaxis of migraine headaches. There is no evidence that divalproex sodium extended-release tablets are useful in the acute treatment of migraine headaches.

1.4 Important Limitations Because of the risk to the fetus of decreased IQ, neurodevelopmental disorders, neural tube defects, and other major congenital malformations, which may occur very early in pregnancy, valproate should not be used to treat women with epilepsy or bipolar disorder who are pregnant or who plan to become pregnant unless other medications have failed to provide adequate symptom control or are otherwise unacceptable. Valproate should not be administered to a woman of childbearing potential unless other medications have failed to provide adequate symptom control or are otherwise unacceptable <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.2 , 5.3 , 5.4 ), Use in Specific Populations ( 8.1 ), and Patient Counseling Information ( 17 )]</span>. For prophylaxis of migraine headaches, divalproex sodium extended-release tablets are contraindicated in women who are pregnant and in women of childbearing potential who are not using effective contraception <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span>.

AND ADMINISTRATION Divalproex sodium extended-release tablets are an extended-release product intended for once-a-day oral administration. Divalproex sodium extended-release tablets should be swallowed whole and should not be crushed or chewed.

• Divalproex sodium extended-release tablets are intended for once-a-day oral administration. Divalproex sodium extended-release tablets should be swallowed whole and should not be crushed or chewed (2.1, 2.2) .
• Mania: Initial dose is 25 mg/kg/day, increasing as rapidly as possible to achieve therapeutic response or desired plasma level (2.1) . The maximum recommended dosage is 60 mg/kg/day (2.1, 2.2) .
• Complex Partial Seizures: Start at 10 mg/kg/day to 15 mg/kg/day, increasing at 1 week intervals by 5 mg/kg/day to 10 mg/kg/day to achieve optimal clinical response; if response is not satisfactory, check valproate plasma level; see full prescribing information for conversion to monotherapy (2.2) . The maximum recommended dosage is 60 mg/kg/day (2.1, 2.2) .
• Absence Seizures: Start at 15 mg/kg/day, increasing at 1 week intervals by 5 mg/kg/day to 10 mg/kg/day until seizure control or limiting side effects (2.2) . The maximum recommended dosage is 60 mg/kg/day (2.1, 2.2) .
• Migraine: The recommended starting dose is 500 mg/day for 1 week, thereafter increasing to 1,000 mg/day (2.3) .

2.1 Mania Divalproex sodium extended-release tablets are administered orally. The recommended initial dose is 25 mg/kg/day given once daily. The dose should be increased as rapidly as possible to achieve the lowest therapeutic dose which produces the desired clinical effect or the desired range of plasma concentrations. In a placebo-controlled clinical trial of acute mania or mixed type, patients were dosed to a clinical response with a trough plasma concentration between 85 mcg/mL and 125 mcg/mL. The maximum recommended dosage is 60 mg/kg/day. There is no body of evidence available from controlled trials to guide a clinician in the longer term management of a patient who improves during divalproex sodium extended-release tablets treatment of an acute manic episode. While it is generally agreed that pharmacological treatment beyond an acute response in mania is desirable, both for maintenance of the initial response and for prevention of new manic episodes, there are no data to support the benefits of divalproex sodium extended-release tablets in such longer-term treatment (i.e., beyond 3 weeks).

2.2 Epilepsy Divalproex sodium extended-release tablets are administered orally and must be swallowed whole. As divalproex sodium extended-release tablets dosage is titrated upward, concentrations of clonazepam, diazepam, ethosuximide, lamotrigine, tolbutamide, phenobarbital, carbamazepine and/or phenytoin may be affected <span class="opacity-50 text-xs">[see Drug Interactions (7.2) ]</span> .

Complex Partial Seizures

For adults and children 10 years of age or older. Monotherapy (Initial Therapy) Divalproex sodium extended-release tablets have not been systematically studied as initial therapy. Patients should initiate therapy at 10 mg/kg/day to 15 mg/kg/day. The dosage should be increased by 5 mg/kg/week to 10 mg/kg/week to achieve optimal clinical response. Ordinarily, optimal clinical response is achieved at daily doses below 60 mg/kg/day. If satisfactory clinical response has not been achieved, plasma levels should be measured to determine whether or not they are in the usually accepted therapeutic range (50 mcg/mL to 100 mcg/mL). No recommendation regarding the safety of valproate for use at doses above 60 mg/kg/day can be made. The probability of thrombocytopenia increases significantly at total trough valproate plasma concentrations above 110 mcg/mL in females and 135 mcg/mL in males. The benefit of improved seizure control with higher doses should be weighed against the possibility of a greater incidence of adverse reactions. Conversion to Monotherapy Patients should initiate therapy at 10 mg/kg/day to 15 mg/kg/day. The dosage should be increased by 5 mg/kg/week to 10 mg/kg/week to achieve optimal clinical response. Ordinarily, optimal clinical response is achieved at daily doses below 60 mg/kg/day. If satisfactory clinical response has not been achieved, plasma levels should be measured to determine whether or not they are in the usually accepted therapeutic range (50 mcg/mL to 100 mcg/mL). No recommendation regarding the safety of valproate for use at doses above 60 mg/kg/day can be made. Concomitant antiepilepsy drug (AED) dosage can ordinarily be reduced by approximately 25% every 2 weeks. This reduction may be started at initiation of divalproex sodium extended-release tablets therapy or delayed by 1 to 2 weeks if there is a concern that seizures are likely to occur with a reduction. The speed and duration of withdrawal of the concomitant AED can be highly variable and patients should be monitored closely during this period for increased seizure frequency.

Adjunctive Therapy

Divalproex sodium extended-release tablets may be added to the patient's regimen at a dosage of 10 mg/kg/day to 15 mg/kg/day. The dosage may be increased by 5 mg/kg/week to 10 mg/kg/week to achieve optimal clinical response. Ordinarily, optimal clinical response is achieved at daily doses below 60 mg/kg/day. If satisfactory clinical response has not been achieved, plasma levels should be measured to determine whether or not they are in the usually accepted therapeutic range (50 mcg/mL to 100 mcg/mL). No recommendation regarding the safety of valproate for use at doses above 60 mg/kg/day can be made. In a study of adjunctive therapy for complex partial seizures in which patients were receiving either carbamazepine or phenytoin in addition to valproate, no adjustment of carbamazepine or phenytoin dosage was needed [see Clinical Studies (14.2) ] . However, since valproate may interact with these or other concurrently administered AEDs as well as other drugs, periodic plasma concentration determinations of concomitant AEDs are recommended during the early course of therapy [see Drug Interactions (7) ] . Simple and Complex Absence Seizures The recommended initial dose is 15 mg/kg/day, increasing at one week intervals by 5 mg/kg/day to 10 mg/kg/day until seizures are controlled or side effects preclude further increases. The maximum recommended dosage is 60 mg/kg/day. A good correlation has not been established between daily dose, serum concentrations, and therapeutic effect. However, therapeutic valproate serum concentration for most patients with absence seizures is considered to range from 50 mcg/mL to 100 mcg/mL. Some patients may be controlled with lower or higher serum concentrations [see Clinical Pharmacology (12.3) ] . As divalproex sodium extended-release tablets dosage is titrated upward, blood concentrations of phenobarbital and/or phenytoin may be affected [see Drug Interactions (7.2) ] . Antiepilepsy drugs should not be abruptly discontinued in patients in whom the drug is administered to prevent major seizures because of the strong possibility of precipitating status epilepticus with attendant hypoxia and threat to life.

2.3 Migraine Divalproex sodium extended-release tablets are indicated for prophylaxis of migraine headaches in adults. The recommended starting dose is 500 mg once daily for 1 week, thereafter increasing to 1,000 mg once daily. Although doses other than 1,000 mg once daily of divalproex sodium extended-release tablets have not been evaluated in patients with migraine, the effective dose range of divalproex sodium delayed-release tablets in these patients is 500 mg/day to 1,000 mg/day. As with other valproate products, doses of divalproex sodium extended-release tablets should be individualized and dose adjustment may be necessary. If a patient requires smaller dose adjustments than that available with divalproex sodium extended-release tablets, divalproex sodium delayed-release tablets should be used instead.

2.4 Conversion from Divalproex Sodium Delayed-Release Tablets to Divalproex Sodium Extended-Release Tablets In adult patients and pediatric patients 10 years of age or older with epilepsy previously receiving divalproex sodium delayed-release tablets, divalproex sodium extended-release tablets should be administered once-daily using a dose 8% to 20% higher than the total daily dose of divalproex sodium delayed-release tablets (Table 1). For patients whose divalproex sodium delayed-release tablets total daily dose cannot be directly converted to divalproex sodium extended-release tablets, consideration may be given at the clinician’s discretion to increase the patient’s divalproex sodium delayed-release tablets total daily dose to the next higher dosage before converting to the appropriate total daily dose of divalproex sodium extended-release tablets.

Table

1.

Dose Conversion Divalproex Sodium

Delayed-Release Tablets Divalproex Sodium Extended-Release Tablets Total Daily Dose (mg) (mg) 500* to 625 750 750* to 875 1,000 1,000* to 1,125 1,250 1,250 to 1,375 1,500 1,500 to 1,625 1,750 1,750 2,000 1,875 to 2,000 2,250 2,125 to 2,250 2,500 2,375 2,750 2,500 to 2,750 3,000 2,875 3,250 3,000 to 3,125 3,500 * These total daily doses of divalproex sodium delayed-release tablets cannot be directly converted to an 8% to 20% higher total daily dose of divalproex sodium extended-release tablets because the required dosing strengths of divalproex sodium extended-release tablets are not available. Consideration may be given at the clinician's discretion to increase the patient's divalproex sodium delayed-release tablets total daily dose to the next higher dosage before converting to the appropriate total daily dose of divalproex sodium extended-release tablets. There is insufficient data to allow a conversion factor recommendation for patients with divalproex sodium delayed-release tablets doses above 3,125 mg/day. Plasma valproate C min concentrations for divalproex sodium extended-release tablets on average are equivalent to divalproex sodium delayed-release tablets, but may vary across patients after conversion. If satisfactory clinical response has not been achieved, plasma levels should be measured to determine whether or not they are in the usually accepted therapeutic range (50 mcg/mL to 100 mcg/mL) [see Clinical Pharmacology (12.2) ] .

2.5 General Dosing Advice Dosing in Elderly Patients Due to a decrease in unbound clearance of valproate and possibly a greater sensitivity to somnolence in the elderly, the starting dose should be reduced in these patients. Starting doses in the elderly lower than 250 mg can only be achieved by the use of divalproex sodium delayed-release tablets. Dosage should be increased more slowly and with regular monitoring for fluid and nutritional intake, dehydration, somnolence, and other adverse reactions. Dose reductions or discontinuation of valproate should be considered in patients with decreased food or fluid intake and in patients with excessive somnolence. The ultimate therapeutic dose should be achieved on the basis of both tolerability and clinical response <span class="opacity-50 text-xs">[see Warnings and Precautions (5.16) , Use in Specific Populations (8.5) and Clinical Pharmacology (12.3) ]</span> . Dose-Related Adverse Reactions The frequency of adverse effects (particularly elevated liver enzymes and thrombocytopenia) may be dose-related. The probability of thrombocytopenia appears to increase significantly at total valproate concentrations of ≥ 110 mcg/mL (females) or ≥ 135 mcg/mL (males) <span class="opacity-50 text-xs">[see Warnings and Precautions (5.8) ]</span> . The benefit of improved therapeutic effect with higher doses should be weighed against the possibility of a greater incidence of adverse reactions. G.I.

Irritation

Patients who experience G.I. irritation may benefit from administration of the drug with food or by slowly building up the dose from an initial low level.

Compliance

Patients should be informed to take divalproex sodium extended-release tablets every day as prescribed. If a dose is missed it should be taken as soon as possible, unless it is almost time for the next dose. If a dose is skipped, the patient should not double the next dose.

2.6 Dosing in Patients Taking Rufinamide Patients stabilized on rufinamide before being prescribed valproate should begin valproate therapy at a low dose and titrate to a clinically effective dose <span class="opacity-50 text-xs">[see Drug Interactions (7.2) ]</span> .

4 CONTRAINDICATIONS

• Divalproex sodium delayed-release tablets should not be administered to patients with hepatic disease or significant hepatic dysfunction [see Warnings and Precautions ( 5.1 )].
• Divalproex sodium delayed-release tablets are contraindicated in patients known to have mitochondrial disorders caused by mutations in mitochondrial DNA polymerase γ (POLG; e.g., Alpers-Huttenlocher Syndrome) and children under two years of age who are suspected of having a POLG-related disorder [see Warnings and Precautions (5.1)].
• Divalproex sodium delayed-release tablets are contraindicated in patients with known hypersensitivity to the drug [ see Warnings and Precautions (5.12)].
• Divalproex sodium delayed-release tablets are contraindicated in patients with known urea cycle disorders [see Warnings and Precautions (5.6)].
• For use in prophylaxis of migraine headaches: Divalproex sodium delayed-release tablets are contraindicated in women who are pregnant and in women of childbearing potential who are not using effective contraception [see Warnings and Precautions (5.2, 5.3, 5.4) and Use in Specific Populations (8.1)].
• Hepatic disease or significant hepatic dysfunction ( 4 , 5.1 )
• Known mitochondrial disorders caused by mutations in mitochondrial DNA polymerase γ (POLG) ( 4 , Error! Hyperlink reference not valid. )
• Suspected POLG-related disorder in children under two years of age ( 4 , Error! Hyperlink reference not valid. )
• Known hypersensitivity to the drug ( 4 , 5.12 )
• Urea cycle disorders ( 4 , 5.6 )
• Prophylaxis of migraine headaches: Pregnant women, women of childbearing potential not using effective contraception ( 4 , Error! Hyperlink reference not valid. )

REACTIONS Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. Most common adverse reactions (reported >5%) reported in patients are abdominal pain, accidental injury, alopecia, ambylopia/blurred vision, amnesia, anorexia, asthenia, ataxia, back pain, bronchitis, constipation, depression, diarrhea, diplopia, dizziness, dyspepsia, dyspnea, ecchymosis, emotional lability, fever, flu syndrome, headache, increased appetite, infection, insomnia, nausea, nervousness, nystagmus, peripheral edema, pharyngitis, rash, rhinitis, somnolence, thinking abnormal, thrombocytopenia, tinnitus, tremor, vomiting, weight gain, weight loss, ( 6.1 , 6.2 , 6.3 ). To report SUSPECTED ADVERSE REACTIONS, contact Dr. Reddy’s Laboratories Inc., at 1-888-375-3784 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

6.1 Mania The incidence of treatment-emergent events has been ascertained based on combined data from two three week placebo-controlled clinical trials of divalproex sodium in the treatment of manic episodes associated with bipolar disorder. The adverse reactions were usually mild or moderate in intensity, but sometimes were serious enough to interrupt treatment. In clinical trials, the rates of premature termination due to intolerance were not statistically different between placebo, divalproex sodium, and lithium carbonate. A total of 4%, 8% and 11% of patients discontinued therapy due to intolerance in the placebo, divalproex sodium, and lithium carbonate groups, respectively.

Table

2 summarizes those adverse reactions reported for patients in these trials where the incidence rate in the divalproex sodium-treated group was greater than 5% and greater than the placebo incidence, or where the incidence in the divalproex sodium-treated group was statistically significantly greater than the placebo group. Vomiting was the only reaction that was reported by significantly (p ≤ 0.05) more patients receiving divalproex sodium compared to placebo.

Table

2.

Adverse Reactions

Reported by > 5% of Divalproex sodium-Treated Patients During Placebo-Controlled Trials of Acute Mania 1 Adverse Reaction Divalproex sodium (n = 89) Placebo (n = 97)

Nausea

22% 15% Somnolence 19% 12% Dizziness 12% 4% Vomiting 12% 3% Accidental Injury 11% 5% Asthenia 10% 7% Abdominal pain 9% 8% Dyspepsia 9% 8% Rash 6% 3% 1. The following adverse reactions occurred at an equal or greater incidence for placebo than for Divalproex sodium: back pain, headache, constipation, diarrhea, tremor, and pharyngitis. The following additional adverse reactions were reported by greater than 1% but not more than 5% of the 89 divalproex sodium-treated patients in controlled clinical trials: Body as a Whole: Chest pain, chills, chills and fever, fever, neck pain, neck rigidity.

Cardiovascular

System: Hypertension, hypotension, palpitations, postural hypotension, tachycardia, vasodilation.

Digestive

System: Anorexia, fecal incontinence, flatulence, gastroenteritis, glossitis, periodontal abscess. Hemic and Lymphatic System: Ecchymosis. Metabolic and Nutritional Disorders: Edema, peripheral edema.

Musculoskeletal

System: Arthralgia, arthrosis, leg cramps, twitching.

Nervous

System: Abnormal dreams, abnormal gait, agitation, ataxia, catatonic reaction, confusion, depression, diplopia, dysarthria, hallucinations, hypertonia, hypokinesia, insomnia, paresthesia, reflexes increased, tardive dyskinesia, thinking abnormalities, vertigo.

Respiratory

System: Dyspnea, rhinitis. Skin and Appendages: Alopecia, discoid lupus erythematosus, dry skin, furunculosis, maculopapular rash, seborrhea.

Special

Senses: Amblyopia, conjunctivitis, deafness, dry eyes, ear pain, eye pain, tinnitus.

Urogenital

System: Dysmenorrhea, dysuria, urinary incontinence.

6.2 Epilepsy Based on a placebo-controlled trial of adjunctive therapy for treatment of complex partial seizures, divalproex sodium was generally well tolerated with most adverse reactions rated as mild to moderate in severity. Intolerance was the primary reason for discontinuation in the divalproex sodium-treated patients (6%), compared to 1% of placebo-treated patients.

Table

3 lists treatment-emergent adverse reactions which were reported by ≥ 5% of divalproex sodium-treated patients and for which the incidence was greater than in the placebo group, in the placebo-controlled trial of adjunctive therapy for treatment of complex partial seizures. Since patients were also treated with other antiepilepsy drugs, it is not possible, in most cases, to determine whether the following adverse reactions can be ascribed to divalproex sodium alone, or the combination of divalproex sodium and other antiepilepsy drugs.

Table

3.

Adverse Reactions

Reported by ≥ 5% of Patients Treated with Divalproex sodium During Placebo-Controlled Trial of Adjunctive Therapy for Complex Partial Seizures Body System/Reaction Divalproex sodium (%) (n = 77) Placebo (%) (n = 70) Body as a Whole Headache 31 21 Asthenia 27 7 Fever 6 4 Gastrointestinal System Nausea 48 14 Vomiting 27 7 Abdominal Pain 23 6 Diarrhea 13 6 Anorexia 12 0 Dyspepsia 8 4 Constipation 5 1 Nervous System Somnolence 27 11 Tremor 25 6 Dizziness 25 13 Diplopia 16 9 Amblyopia/Blurred Vision 12 9 Ataxia 8 1 Nystagmus 8 1 Emotional Lability 6 4 Thinking Abnormal 6 0 Amnesia 5 1 Respiratory System Flu Syndrome 12 9 Infection 12 6 Bronchitis 5 1 Rhinitis 5 4 Other Alopecia 6 1 Weight Loss 6 0 Table 4 lists treatment-emergent adverse reactions which were reported by ≥ 5% of patients in the high dose valproate group, and for which the incidence was greater than in the low dose group, in a controlled trial of divalproex sodium monotherapy treatment of complex partial seizures. Since patients were being titrated off another antiepilepsy drug during the first portion of the trial, it is not possible, in many cases, to determine whether the following adverse reactions can be ascribed to Divalproex sodium alone, or the combination of valproate and other antiepilepsy drugs.

Body System/Reaction

High Dose (%) (n = 131)

Low

Dose (%) (n = 134) Body as a Whole Asthenia 21 10 Digestive System Nausea 34 26 Diarrhea 23 19 Vomiting 23 15 Abdominal Pain 12 9 Anorexia 11 4 Dyspepsia 11 10 Hemic/Lymphatic System Thrombocytopenia 24 1 Ecchymosis 5 4 Metabolic/Nutritional Weight Gain 9 4 Peripheral Edema 8 3 Nervous System Tremor 57 19 Somnolence 30 18 Dizziness 18 13 Insomnia 15 9 Nervousness 11 7 Amnesia 7 4 Nystagmus 7 1 Depression 5 4 Respiratory System Infection 20 13 Pharyngitis 8 2 Dyspnea 5 1 Skin and Appendages Alopecia 24 13 Special Senses Amblyopia/Blurred Vision 8 4 Tinnitus 7 1 1. Headache was the only adverse reaction that occurred in ≥ 5% of patients in the high dose group and at an equal or greater incidence in the low dose group. The following additional adverse reactions were reported by greater than 1% but less than 5% of the 358 patients treated with valproate in the controlled trials of complex partial seizures: Body as a Whole: Back pain, chest pain, malaise.

Cardiovascular

System: Tachycardia, hypertension, palpitation.

Digestive

System: Increased appetite, flatulence, hematemesis, eructation, pancreatitis, periodontal abscess. Hemic and Lymphatic System: Petechia. Metabolic and Nutritional Disorders: SGOT increased, SGPT increased.

Musculoskeletal

System: Myalgia, twitching, arthralgia, leg cramps, myasthenia.

Nervous

System: Anxiety, confusion, abnormal gait, paresthesia, hypertonia, incoordination, abnormal dreams, personality disorder.

Respiratory

System: Sinusitis, cough increased, pneumonia, epistaxis. Skin and Appendages: Rash, pruritus, dry skin.

Special

Senses: Taste perversion, abnormal vision, deafness, otitis media.

Urogenital

System: Urinary incontinence, vaginitis, dysmenorrhea, amenorrhea, urinary frequency.

6.3 Migraine Based on two placebo-controlled clinical trials and their long term extension, valproate was generally well tolerated with most adverse reactions rated as mild to moderate in severity. Of the 202 patients exposed to valproate in the placebo-controlled trials, 17% discontinued for intolerance. This is compared to a rate of 5% for the 81 placebo patients. Including the long term extension study, the adverse reactions reported as the primary reason for discontinuation by ≥ 1% of 248 valproate-treated patients were alopecia (6%), nausea and/or vomiting (5%), weight gain (2%), tremor (2%), somnolence (1%), elevated SGOT and/or SGPT (1%), and depression (1%).

Table

5 includes those adverse reactions reported for patients in the placebo-controlled trials where the incidence rate in the divalproex sodium-treated group was greater than 5% and was greater than that for placebo patients.

Table

5.

Adverse Reactions

Reported by > 5% of Divalproex sodium-Treated Patients During Migraine Placebo-Controlled Trials with a Greater Incidence Than Patients Taking Placebo 1 Body System Reaction Divalproex sodium (N = 202) Placebo (N = 81)

Gastrointestinal System Nausea

31% 10% Dyspepsia 13% 9% Diarrhea 12% 7% Vomiting 11% 1% Abdominal pain 9% 4% Increased appetite 6% 4% Nervous System Asthenia 20% 9% Somnolence 17% 5% Dizziness 12% 6% Tremor 9% 0% Other Weight gain 8% 2% Back pain 8% 6% Alopecia 7% 1% 1. The following adverse reactions occurred in at least 5% of divalproex sodium-treated patients and at an equal or greater incidence for placebo than for divalproex sodium: flu syndrome and pharyngitis. The following additional adverse reactions were reported by greater than 1% but not more than 5% of the 202 divalproex sodium-treated patients in the controlled clinical trials: Body as a Whole: Chest pain, chills, face edema, fever and malaise.

Cardiovascular

System: Vasodilatation.

Digestive

System: Anorexia, constipation, dry mouth, flatulence, gastrointestinal disorder (unspecified), and stomatitis. Hemic and Lymphatic System: Ecchymosis. Metabolic and Nutritional Disorders: Peripheral edema, SGOT increase, and SGPT increase.

Musculoskeletal

System: Leg cramps and myalgia.

Nervous

System: Abnormal dreams, amnesia, confusion, depression, emotional lability, insomnia, nervousness, paresthesia, speech disorder, thinking abnormalities, and vertigo.

Respiratory

System: Cough increased, dyspnea, rhinitis, and sinusitis. Skin and Appendages: Pruritus and rash.

Special

Senses: Conjunctivitis, ear disorder, taste perversion, and tinnitus.

Urogenital

System: Cystitis, metrorrhagia, and vaginal hemorrhage.

6.4 Other Patient Populations Adverse reactions that have been reported with all dosage forms of valproate from epilepsy trials, spontaneous reports, and other sources are listed below by body system.

Gastrointestinal

The most commonly reported side effects at the initiation of therapy are nausea, vomiting, and indigestion. These effects are usually transient and rarely require discontinuation of therapy. Diarrhea, abdominal cramps, and constipation have been reported. Both anorexia with some weight loss and increased appetite with weight gain have also been reported. The administration of delayed-release divalproex sodium may result in reduction of gastrointestinal side effects in some patients.

Cns

Effects Sedative effects have occurred in patients receiving valproate alone but occur most often in patients receiving combination therapy. Sedation usually abates upon reduction of other antiepileptic medication. Tremor (may be dose-related), hallucinations, ataxia, headache, nystagmus, diplopia, asterixis, "spots before eyes", dysarthria, dizziness, confusion, hypesthesia, vertigo, incoordination, and parkinsonism have been reported with the use of valproate. Rare cases of coma have occurred in patients receiving valproate alone or in conjunction with phenobarbital. In rare instances encephalopathy with or without fever has developed shortly after the introduction of valproate monotherapy without evidence of hepatic dysfunction or inappropriately high plasma valproate levels. Although recovery has been described following drug withdrawal, there have been fatalities in patients with hyperammonemic encephalopathy, particularly in patients with underlying urea cycle disorders [see Warnings and Precautions (5.5) ]. Several reports have noted reversible cerebral atrophy and dementia in association with valproate therapy.

Dermatologic

Transient hair loss, skin rash, photosensitivity, generalized pruritus, erythema multiforme, and Stevens-Johnson syndrome. Rare cases of toxic epidermal necrolysis have been reported including a fatal case in a 6 month old infant taking valproate and several other concomitant medications. An additional case of toxic epidermal necrosis resulting in death was reported in a 35 year old patient with AIDS taking several concomitant medications and with a history of multiple cutaneous drug reactions. Serious skin reactions have been reported with concomitant administration of lamotrigine and valproate [see Drug Interactions (7.2) ].

Psychiatric

Emotional upset, depression, psychosis, aggression, hyperactivity, hostility, and behavioral deterioration.

Musculoskeletal

Weakness.

Hematologic

Thrombocytopenia and inhibition of the secondary phase of platelet aggregation may be reflected in altered bleeding time, petechiae, bruising, hematoma formation, epistaxis, and frank hemorrhage [see Warnings and Precautions (5.7) and Drug Interactions (7) ]. Relative lymphocytosis, macrocytosis, hypofibrinogenemia, leucopenia, eosinophilia, anemia including macrocytic with or without folate deficiency, bone marrow suppression, pancytopenia, aplastic anemia, agranulocytosis, and acute intermittent porphyria.

Hepatic

Minor elevations of transaminases (e.g., SGOT and SGPT) and LDH are frequent and appear to be dose-related. Occasionally, laboratory test results include increases in serum bilirubin and abnormal changes in other liver function tests. These results may reflect potentially serious hepatotoxicity [see Warnings and Precautions (5.1) ].

Endocrine

Irregular menses, secondary amenorrhea, breast enlargement, galactorrhea, and parotid gland swelling. Abnormal thyroid function tests [see Warnings and Precautions (5.15) ]. There have been rare spontaneous reports of polycystic ovary disease. A cause and effect relationship has not been established.

Pancreatic

Acute pancreatitis including fatalities [see Warnings and Precautions (5.4) ].

Metabolic

Hyperammonemia [see Warnings and Precautions (5.8) ], hyponatremia, and inappropriate ADH secretion. There have been rare reports of Fanconi's syndrome occurring chiefly in children. Decreased carnitine concentrations have been reported although the clinical relevance is undetermined. Hyperglycinemia has occurred and was associated with a fatal outcome in a patient with preexistent nonketotic hyperglycinemia.

Genitourinary

Enuresis and urinary tract infection.

Special Senses

Hearing loss, either reversible or irreversible, has been reported; however, a cause and effect relationship has not been established. Ear pain has also been reported.

Other

Allergic reaction, anaphylaxis, edema of the extremities, lupus erythematosus, bone pain, cough increased, pneumonia, otitis media, bradycardia, cutaneous vasculitis, fever, and hypothermia. There have been reports of developmental delay, autism and/or autism spectrum disorder in the offspring of women exposed to valproate during pregnancy.

AND PRECAUTIONS Birth defects, decreased IQ, and neurodevelopmental disorders following in utero exposure: Should not be used to treat women with epilepsy or bipolar disorder who are pregnant or who plan to become pregnant or to treat a woman of childbearing potential unless other medications have failed to provide adequate symptom control or are otherwise unacceptable ( 5.2 , 5.3 , 5.4 ) Pancreatitis: Divalproex sodium extended-release tablets should ordinarily be discontinued ( 5.5 ) Suicidal behavior or ideation: Antiepileptic drugs, including divalproex sodium extended-release tablets, increase the risk of suicidal thoughts or behavior ( 5.7 ) Bleeding and other hematopoietic disorders: Monitor platelet counts and coagulation tests ( 5.8 ) Hyperammonemia and hyperammonemic encephalopathy: Measure ammonia level if unexplained lethargy and vomiting or changes in mental status, and also with concomitant topiramate use; consider discontinuation of valproate therapy ( 5.6 , 5.9 , 5.10 ) Hypothermia: Hypothermia has been reported during valproate therapy with or without associated hyperammonemia. This adverse reaction can also occur in patients using concomitant topiramate ( 5.11 )

Drug

Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan hypersensitivity reaction, serious dermatologic reactions, and angioedema: Discontinue divalproex sodium extended-release tablets unless an alternate etiology is established ( 5.12 , 5.13 , 5.14 ).

5.1 Hepatotoxicity General Information on Hepatotoxicity Hepatic failure resulting in fatalities has occurred in patients receiving valproate. These incidents usually have occurred during the first six months of treatment. Serious or fatal hepatotoxicity may be preceded by non-specific symptoms such as malaise, weakness, lethargy, facial edema, anorexia, and vomiting. In patients with epilepsy, a loss of seizure control may also occur. Patients should be monitored closely for appearance of these symptoms. Serum liver tests should be performed prior to therapy and at frequent intervals thereafter, especially during the first six months of valproate therapy. However, healthcare providers should not rely totally on serum biochemistry since these tests may not be abnormal in all instances, but should also consider the results of careful interim medical history and physical examination. Caution should be observed when administering valproate products to patients with a prior history of hepatic disease. Patients on multiple anticonvulsants, children, those with congenital metabolic disorders, those with severe seizure disorders accompanied by mental retardation, and those with organic brain disease may be at particular risk. See below, &quot;Patients with Known or Suspected Mitochondrial Disease.&quot; Experience has indicated that children under the age of two years are at a considerably increased risk of developing fatal hepatotoxicity, especially those with the aforementioned conditions. When divalproex sodium extended-release tablet are used in this patient group, it should be used with extreme caution and as a sole agent. The benefits of therapy should be weighed against the risks. In progressively older patient groups experience in epilepsy has indicated that the incidence of fatal hepatotoxicity decreases considerably. Patients with Known or Suspected Mitochondrial Disease Divalproex sodium extended-release tablets are contraindicated in patients known to have mitochondrial disorders caused by POLG mutations and children under two years of age who are clinically suspected of having a mitochondrial disorder <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span>. Valproate-induced acute liver failure and liver-related deaths have been reported in patients with hereditary neurometabolic syndromes caused by mutations in the gene for mitochondrial DNA polymerase γ (POLG) (e.g., Alpers- Huttenlocher Syndrome) at a higher rate than those without these syndromes. Most of the reported cases of liver failure in patients with these syndromes have been identified in children and adolescents. POLG-related disorders should be suspected in patients with a family history or suggestive symptoms of a POLG-related disorder, including but not limited to unexplained encephalopathy, refractory epilepsy (focal, myoclonic), status epilepticus at presentation, developmental delays, psychomotor regression, axonal sensorimotor neuropathy, myopathy cerebellar ataxia, ophthalmoplegia, or complicated migraine with occipital aura. POLG mutation testing should be performed in accordance with current clinical practice for the diagnostic evaluation of such disorders. The A467T and W748S mutations are present in approximately 2/3 of patients with autosomal recessive POLG-related disorders. In patients over two years of age who are clinically suspected of having a hereditary mitochondrial disease, divalproex sodium extended-release tablets should only be used after other anticonvulsants have failed. This older group of patients should be closely monitored during treatment with divalproex sodium extended-release tablets for the development of acute liver injury with regular clinical assessments and serum liver test monitoring. The drug should be discontinued immediately in the presence of significant hepatic dysfunction, suspected or apparent. In some cases, hepatic dysfunction has progressed in spite of discontinuation of drug <span class="opacity-50 text-xs">[see Boxed Warning and Contraindications ( 4 )]</span> .

5.2 Structural Birth Defects Valproate can cause fetal harm when administered to a pregnant woman. Pregnancy registry data show that maternal valproate use can cause neural tube defects and other structural abnormalities (e.g., craniofacial defects, cardiovascular malformations, hypospadias, limb malformations). The rate of congenital malformations among babies born to mothers using valproate is about four times higher than the rate among babies born to epileptic mothers using other anti-seizure monotherapies. Evidence suggests that folic acid supplementation prior to conception and during the first trimester of pregnancy decreases the risk for congenital neural tube defects in the general population <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 )]</span>.

5.3 Decreased IQ Following in utero Exposure Valproate can cause decreased IQ scores following in utero exposure. Published epidemiological studies have indicated that children exposed to valproate in utero have lower cognitive test scores than children exposed in utero to either another antiepileptic drug or to no antiepileptic drugs. The largest of these studies1 is a prospective cohort study conducted in the United States and United Kingdom that found that children with prenatal exposure to valproate (n=62) had lower IQ scores at age 6 (97 [95% C.I. 94-101]) than children with prenatal exposure to the other antiepileptic drug monotherapy treatments evaluated: lamotrigine (108 [95% C.I. 105–110]), carbamazepine (105 [95% C.I. 102–108]), and phenytoin (108 [95% C.I. 104–112]). It is not known when during pregnancy cognitive effects in valproate-exposed children occur. Because the women in this study were exposed to antiepileptic drugs throughout pregnancy, whether the risk for decreased IQ was related to a particular time period during pregnancy could not be assessed. Although all of the available studies have methodological limitations, the weight of the evidence supports the conclusion that valproate exposure in utero can cause decreased IQ in children. In animal studies, offspring with prenatal exposure to valproate had malformations similar to those seen in humans and demonstrated neurobehavioral deficits <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 )]</span>.

5.4 Use in Women of Childbearing Potential Because of the risk to the fetus of decreased IQ, neurodevelopmental disorders, and major congenital malformations (including neural tube defects), which may occur very early in pregnancy, valproate should not be administered to a woman of childbearing potential unless other medications have failed to provide adequate symptom control or are otherwise unacceptable. This is especially important when valproate use is considered for a condition not usually associated with permanent injury or death such as prophylaxis of migraine headaches <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span> . Women should use effective contraception while using valproate. Women of childbearing potential should be counseled regularly regarding the relative risks and benefits of valproate use during pregnancy. This is especially important for women planning a pregnancy and for girls at the onset of puberty; alternative therapeutic options should be considered for these patients <span class="opacity-50 text-xs">[see Boxed Warning and Use in Specific Populations ( 8.1 )]</span>. To prevent major seizures, valproate should not be discontinued abruptly, as this can precipitate status epilepticus with resulting maternal and fetal hypoxia and threat to life. Evidence suggests that folic acid supplementation prior to conception and during the first trimester of pregnancy decreases the risk for congenital neural tube defects in the general population. It is not known whether the risk of neural tube defects or decreased IQ in the offspring of women receiving valproate is reduced by folic acid supplementation. Dietary folic acid supplementation both prior to conception and during pregnancy should be routinely recommended for patients using valproate.

5.5 Pancreatitis Cases of life-threatening pancreatitis have been reported in both children and adults receiving valproate. Some of the cases have been described as hemorrhagic with rapid progression from initial symptoms to death. Some cases have occurred shortly after initial use as well as after several years of use. The rate based upon the reported cases exceeds that expected in the general population and there have been cases in which pancreatitis recurred after rechallenge with valproate. In clinical trials, there were 2 cases of pancreatitis without alternative etiology in 2,416 patients, representing 1,044 patient-years experience. Patients and guardians should be warned that abdominal pain, nausea, vomiting, and/or anorexia can be symptoms of pancreatitis that require prompt medical evaluation. If pancreatitis is diagnosed, divalproex sodium extended-release tablets should ordinarily be discontinued. Alternative treatment for the underlying medical condition should be initiated as clinically indicated <span class="opacity-50 text-xs">[see Boxed Warning ]</span> .

5.6 Urea Cycle Disorders Divalproex sodium extended-release tablets are contraindicated in patients with known urea cycle disorders (UCD). Hyperammonemic encephalopathy, sometimes fatal, has been reported following initiation of valproate therapy in patients with urea cycle disorders, a group of uncommon genetic abnormalities, particularly ornithine transcarbamylase deficiency. Prior to the initiation of divalproex sodium extended-release tablets therapy, evaluation for UCD should be considered in the following patients: 1) those with a history of unexplained encephalopathy or coma, encephalopathy associated with a protein load, pregnancy-related or postpartum encephalopathy, unexplained mental retardation, or history of elevated plasma ammonia or glutamine; 2) those with cyclical vomiting and lethargy, episodic extreme irritability, ataxia, low BUN, or protein avoidance; 3) those with a family history of UCD or a family history of unexplained infant deaths (particularly males); 4) those with other signs or symptoms of UCD. Patients who develop symptoms of unexplained hyperammonemic encephalopathy while receiving valproate therapy should receive prompt treatment (including discontinuation of valproate therapy) and be evaluated for underlying urea cycle disorders <span class="opacity-50 text-xs">[see Contraindications ( 4 ) and Warnings and Precautions ( 5.10 )]</span>.

5.7 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including divalproex sodium extended-release tablets, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior. Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI:1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared to 0.24% among 16,029 placebo-treated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide. The increased risk of suicidal thoughts or behavior with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed. The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication. The risk did not vary substantially by age (5-100 years) in the clinical trials analyzed.

Table

2 shows absolute and relative risk by indication for all evaluated AEDs.

Table

2. Risk by Indication for Antiepileptic Drugs in the Pooled Analysis Indication Placebo Patients with Events Per 1,000 Patients Drug Patients with Events Per 1,000 Patients Relative Risk: Incidence of Events in Drug Patients / Incidence in Placebo Patients Risk Difference: Additional Drug Patients with Events Per 1,000 Patients Epilepsy 1.0 3.4 3.5

2.4 Psychiatric 5.7 8.5 1.5

2.9 Other 1.0 1.8 1.9

0.9 Total 2.4 4.3 1.8

1.9 The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications. Anyone considering prescribing divalproex sodium extended-release tablets or any other AED must balance the risk of suicidal thoughts or behavior with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.

5.8 Bleeding and Other Hematopoietic Disorders Valproate is associated with dose-related thrombocytopenia. In a clinical trial of valproate as monotherapy in patients with epilepsy, 34/126 patients (27%) receiving approximately 50 mg/kg/day on average, had at least one value of platelets ≤ 75 x 10 9 /L. Approximately half of these patients had treatment discontinued, with return of platelet counts to normal. In the remaining patients, platelet counts normalized with continued treatment. In this study, the probability of thrombocytopenia appeared to increase significantly at total valproate concentrations of ≥ 110 mcg/mL (females) or ≥ 135 mcg/mL (males). The therapeutic benefit which may accompany the higher doses should therefore be weighed against the possibility of a greater incidence of adverse effects. Valproate use has also been associated with decreases in other cell lines and myelodysplasia. Because of reports of cytopenias, inhibition of the secondary phase of platelet aggregation, and abnormal coagulation parameters, (e.g., low fibrinogen, coagulation factor deficiencies, acquired von Willebrand&apos;s disease), measurements of complete blood counts and coagulation tests are recommended before initiating therapy and at periodic intervals. It is recommended that patients receiving divalproex sodium extended-release tablets be monitored for blood counts and coagulation parameters prior to planned surgery and during pregnancy <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 )]</span> . Evidence of hemorrhage, bruising, or a disorder of hemostasis/coagulation is an indication for reduction of the dosage or withdrawal of therapy.

5.9 Hyperammonemia Hyperammonemia has been reported in association with valproate therapy and may be present despite normal liver function tests. In patients who develop unexplained lethargy and vomiting or changes in mental status, hyperammonemic encephalopathy should be considered and an ammonia level should be measured. Hyperammonemia should also be considered in patients who present with hypothermia <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.11 )]</span> . If ammonia is increased, valproate therapy should be discontinued. Appropriate interventions for treatment of hyperammonemia should be initiated, and such patients should undergo investigation for underlying urea cycle disorders <span class="opacity-50 text-xs">[see Contraindications ( 4 ) and Warnings and Precautions ( 5.6 , 5.10 )]</span> . During the placebo controlled pediatric mania trial, one (1) in twenty (20) adolescents (5%) treated with valproate developed increased plasma ammonia levels compared to no (0) patients treated with placebo. Asymptomatic elevations of ammonia are more common and when present, require close monitoring of plasma ammonia levels. If the elevation persists, discontinuation of valproate therapy should be considered.

5.10 Hyperammonemia and Encephalopathy Associated with Concomitant Topiramate Use Concomitant administration of topiramate and valproate has been associated with hyperammonemia with or without encephalopathy in patients who have tolerated either drug alone. Clinical symptoms of hyperammonemic encephalopathy often include acute alterations in level of consciousness and/or cognitive function with lethargy or vomiting. Hypothermia can also be a manifestation of hyperammonemia <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.11 )]</span> . In most cases, symptoms and signs abated with discontinuation of either drug. This adverse reaction is not due to a pharmacokinetic interaction. Patients with inborn errors of metabolism or reduced hepatic mitochondrial activity may be at an increased risk for hyperammonemia with or without encephalopathy. Although not studied, an interaction of topiramate and valproate may exacerbate existing defects or unmask deficiencies in susceptible persons. In patients who develop unexplained lethargy, vomiting, or changes in mental status, hyperammonemic encephalopathy should be considered and an ammonia level should be measured <span class="opacity-50 text-xs">[see Contraindications ( 4 ) and Warnings and Precautions ( 5.6 , 5.9 )]</span> .

5.11 Hypothermia Hypothermia, defined as an unintentional drop in body core temperature to &lt; 35°C (95°F), has been reported in association with valproate therapy both in conjunction with and in the absence of hyperammonemia. This adverse reaction can also occur in patients using concomitant topiramate with valproate after starting topiramate treatment or after increasing the daily dose of topiramate <span class="opacity-50 text-xs">[see Drug Interactions ( 7.3 )]</span>. Consideration should be given to stopping valproate in patients who develop hypothermia, which may be manifested by a variety of clinical abnormalities including lethargy, confusion, coma, and significant alterations in other major organ systems such as the cardiovascular and respiratory systems. Clinical management and assessment should include examination of blood ammonia levels.

5.12 Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity Reactions Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multiorgan hypersensitivity, has been reported in patients taking valproate. DRESS may be fatal or life-threatening. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy, and/or facial swelling, in association with other organ system involvement, such as hepatitis, nephritis, hematological abnormalities, myocarditis, or myositis sometimes resembling an acute viral infection. Eosinophilia is often present. Because this disorder is variable in its expression, other organ systems not noted here may be involved. It is important to note that early manifestations of hypersensitivity, such as fever or lymphadenopathy, may be present even though rash is not evident. If such signs or symptoms are present, the patient should be evaluated immediately. Valproate should be discontinued if an alternative etiology for the signs or symptoms cannot be established.

5.13 Serious Dermatologic Reactions

5.13 Serious Dermatologic Reactions Serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN), Stevens Johnson syndrome (SJS), Acute Generalized Exanthematous Pustulosis (AGEP), and Erythema Multiforme (EM) have been reported with valproate treatment. Valproate should be discontinued at the first sign of a rash, unless the rash is clearly not drug related. If a rash occurs, the patient should be evaluated for signs and symptoms of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) <span class="opacity-50 text-xs">[see Warnings and Precautions (5.12)]</span> . If signs or symptoms suggest TEN/SJS/AGEP/EM, use of this drug should not be resumed and alternative therapy should be considered.

5.14 Angioedema

5.14 Angioedema Angioedema has been reported in patients treated with valproate in the postmarketing setting. Valproate should be discontinued immediately if symptoms of angioedema, such as facial, perioral, or upper airway swelling occur. Valproate should be discontinued permanently if a clear alternative etiology for the reaction cannot be established <span class="opacity-50 text-xs">[see Contraindications (4)]</span>.

5.15 Interaction with Carbapenem Antibiotics Carbapenem antibiotics (for example, ertapenem, imipenem, meropenem; this is not a complete list) may reduce serum valproate concentrations to subtherapeutic levels, resulting in loss of seizure control. Serum valproate concentrations should be monitored frequently after initiating carbapenem therapy. Alternative antibacterial or anticonvulsant therapy should be considered if serum valproate concentrations drop significantly or seizure control deteriorates <span class="opacity-50 text-xs">[see Drug Interactions ( 7.1 )]</span>.

5.16 Somnolence in the Elderly In a double-blind, multicenter trial of valproate in elderly patients with dementia (mean age = 83 years), doses were increased by 125 mg/day to a target dose of 20 mg/kg/day. A significantly higher proportion of valproate patients had somnolence compared to placebo, and although not statistically significant, there was a higher proportion of patients with dehydration. Discontinuations for somnolence were also significantly higher than with placebo. In some patients with somnolence (approximately one-half), there was associated reduced nutritional intake and weight loss. There was a trend for the patients who experienced these events to have a lower baseline albumin concentration, lower valproate clearance, and a higher BUN. In elderly patients, dosage should be increased more slowly and with regular monitoring for fluid and nutritional intake, dehydration, somnolence, and other adverse reactions. Dose reductions or discontinuation of valproate should be considered in patients with decreased food or fluid intake and in patients with excessive somnolence <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.4 )]</span> .

5.17 Monitoring: Drug Plasma Concentration Since valproate may interact with concurrently administered drugs which are capable of enzyme induction, periodic plasma concentration determinations of valproate and concomitant drugs are recommended during the early course of therapy <span class="opacity-50 text-xs">[see Drug Interactions ( 7 )]</span> .

5.18 Effect on Ketone and Thyroid Function Tests Valproate is partially eliminated in the urine as a keto-metabolite which may lead to a false interpretation of the urine ketone test. There have been reports of altered thyroid function tests associated with valproate. The clinical significance of these is unknown.

5.19 Effect on HIV and CMV Viruses Replication There are in vitro studies that suggest valproate stimulates the replication of the HIV and CMV viruses under certain experimental conditions. The clinical consequence, if any, is not known. Additionally, the relevance of these in vitro findings is uncertain for patients receiving maximally suppressive antiretroviral therapy. Nevertheless, these data should be borne in mind when interpreting the results from regular monitoring of the viral load in HIV infected patients receiving valproate or when following CMV infected patients clinically.

5.20 Medication Residue in the Stool There have been rare reports of medication residue in the stool. Some patients have had anatomic (including ileostomy or colostomy) or functional gastrointestinal disorders with shortened GI transit times. In some reports, medication residues have occurred in the context of diarrhea. It is recommended that plasma valproate levels be checked in patients who experience medication residue in the stool, and patients&apos; clinical condition should be monitored. If clinically indicated, alternative treatment may be considered.

INTERACTIONS

• Hepatic enzyme-inducing drugs (e.g., phenytoin, carbamazepine, phenobarbital, primidone, rifampin) can increase valproate clearance, while enzyme inhibitors (e.g., felbamate) can decrease valproate clearance. Therefore increased monitoring of valproate and concomitant drug concentrations and dosage adjustment are indicated whenever enzyme-inducing or inhibiting drugs are introduced or withdrawn ( 7.1 )
• Aspirin, carbapenem antibiotics, estrogen-containing hormonal contraceptives: Monitoring of valproate concentrations is recommended ( 7.1 )
• Co-administration of valproate can affect the pharmacokinetics of other drugs (e.g., diazepam, ethosuximide, lamotrigine, phenytoin) by inhibiting their metabolism or protein binding displacement ( 7.2 )
• Patients stabilized on rufinamide should begin valproate therapy at a low dose, and titrate to clinically effective dose ( 7.2 )
• Dosage adjustment of amitriptyline/nortriptyline, propofol, warfarin, and zidovudine may be necessary if used concomitantly with divalproex sodium extended-release tablets ( 7.2 )
• Topiramate: Hyperammonemia and encephalopathy ( 5.10 , 7.3 )

7.1 Effects of Co-Administered Drugs on Valproate Clearance Drugs that affect the level of expression of hepatic enzymes, particularly those that elevate levels of glucuronosyltransferases (such as ritonavir), may increase the clearance of valproate. For example, phenytoin, carbamazepine, and phenobarbital (or primidone) can double the clearance of valproate. Thus, patients on monotherapy will generally have longer half-lives and higher concentrations than patients receiving polytherapy with antiepilepsy drugs. In contrast, drugs that are inhibitors of cytochrome P450 isozymes, e.g., antidepressants, may be expected to have little effect on valproate clearance because cytochrome P450 microsomal mediated oxidation is a relatively minor secondary metabolic pathway compared to glucuronidation and beta-oxidation. Because of these changes in valproate clearance, monitoring of valproate and concomitant drug concentrations should be increased whenever enzyme inducing drugs are introduced or withdrawn. The following list provides information about the potential for an influence of several commonly prescribed medications on valproate pharmacokinetics. The list is not exhaustive nor could it be, since new interactions are continuously being reported. Drugs for Which a Potentially Important Interaction Has Been Observed Aspirin A study involving the co-administration of aspirin at antipyretic doses (11 to 16 mg/kg) with valproate to pediatric patients (n = 6) revealed a decrease in protein binding and an inhibition of metabolism of valproate. Valproate free fraction was increased 4-fold in the presence of aspirin compared to valproate alone. The β-oxidation pathway consisting of 2-E-valproic acid, 3-OH-valproic acid, and 3-keto valproic acid was decreased from 25% of total metabolites excreted on valproate alone to 8.3% in the presence of aspirin. Whether or not the interaction observed in this study applies to adults is unknown, but caution should be observed if valproate and aspirin are to be co-administered.

Carbapenem

Antibiotics A clinically significant reduction in serum valproic acid concentration has been reported in patients receiving carbapenem antibiotics (for example, ertapenem, imipenem, meropenem; this is not a complete list) and may result in loss of seizure control. The mechanism of this interaction is not well understood. Serum valproic acid concentrations should be monitored frequently after initiating carbapenem therapy. Alternative antibacterial or anticonvulsant therapy should be considered if serum valproic acid concentrations drop significantly or seizure control deteriorates [see Warnings and Precautions (5.13) ] . Estrogen-Containing Hormonal Contraceptives Estrogen-containing hormonal contraceptives may increase the clearance of valproate, which may result in decreased concentration of valproate and potentially increased seizure frequency. Prescribers should monitor serum valproate concentrations and clinical response when adding or discontinuing estrogen containing products. Felbamate A study involving the co-administration of 1,200 mg/day of felbamate with valproate to patients with epilepsy (n = 10) revealed an increase in mean valproate peak concentration by 35% (from 86 to 115 mcg/mL) compared to valproate alone. Increasing the felbamate dose to 2,400 mg/day increased the mean valproate peak concentration to 133 mcg/mL (another 16% increase). A decrease in valproate dosage may be necessary when felbamate therapy is initiated. Rifampin A study involving the administration of a single dose of valproate (7 mg/kg) 36 hours after 5 nights of daily dosing with rifampin (600 mg) revealed a 40% increase in the oral clearance of valproate. Valproate dosage adjustment may be necessary when it is co-administered with rifampin. Drugs for Which Either No Interaction or a Likely Clinically Unimportant Interaction Has Been Observed Antacids A study involving the co-administration of valproate 500 mg with commonly administered antacids (Maalox ® , Trisogel, and Titralac ™ - 160 mEq doses) did not reveal any effect on the extent of absorption of valproate. Chlorpromazine A study involving the administration of 100 to 300 mg/day of chlorpromazine to schizophrenic patients already receiving valproate (200 mg BID) revealed a 15% increase in trough plasma levels of valproate. Haloperidol A study involving the administration of 6 to 10 mg/day of haloperidol to schizophrenic patients already receiving valproate (200 mg BID) revealed no significant changes in valproate trough plasma levels. Cimetidine and Ranitidine Cimetidine and ranitidine do not affect the clearance of valproate.

7.2 Effects of Valproate on Other Drugs Valproate has been found to be a weak inhibitor of some P450 isozymes, epoxide hydrase, and glucuronosyltransferases. The following list provides information about the potential for an influence of valproate co-administration on the pharmacokinetics or pharmacodynamics of several commonly prescribed medications. The list is not exhaustive, since new interactions are continuously being reported. Drugs for Which a Potentially Important Valproate Interaction Has Been Observed Amitriptyline/Nortriptyline Administration of a single oral 50 mg dose of amitriptyline to 15 normal volunteers (10 males and 5 females) who received valproate (500 mg BID) resulted in a 21% decrease in plasma clearance of amitriptyline and a 34% decrease in the net clearance of nortriptyline. Rare postmarketing reports of concurrent use of valproate and amitriptyline resulting in an increased amitriptyline level have been received. Concurrent use of valproate and amitriptyline has rarely been associated with toxicity. Monitoring of amitriptyline levels should be considered for patients taking valproate concomitantly with amitriptyline. Consideration should be given to lowering the dose of amitriptyline/nortriptyline in the presence of valproate. Carbamazepine/carbamazepine-10,11-Epoxide Serum levels of carbamazepine (CBZ) decreased 17% while that of carbamazepine-10,11-epoxide (CBZ-E) increased by 45% upon co-administration of valproate and CBZ to epileptic patients.

Clonazepam

The concomitant use of valproate and clonazepam may induce absence status in patients with a history of absence type seizures.

Diazepam

Valproate displaces diazepam from its plasma albumin binding sites and inhibits its metabolism. Co-administration of valproate (1,500 mg daily) increased the free fraction of diazepam (10 mg) by 90% in healthy volunteers (n = 6). Plasma clearance and volume of distribution for free diazepam were reduced by 25% and 20%, respectively, in the presence of valproate. The elimination half-life of diazepam remained unchanged upon addition of valproate.

Ethosuximide

Valproate inhibits the metabolism of ethosuximide. Administration of a single ethosuximide dose of 500 mg with valproate (800 to 1,600 mg/day) to healthy volunteers (n = 6) was accompanied by a 25% increase in elimination half-life of ethosuximide and a 15% decrease in its total clearance as compared to ethosuximide alone. Patients receiving valproate and ethosuximide, especially along with other anticonvulsants, should be monitored for alterations in serum concentrations of both drugs. Lamotrigine In a steady-state study involving 10 healthy volunteers, the elimination half-life of lamotrigine increased from 26 to 70 hours with valproate co-administration (a 165% increase). The dose of lamotrigine should be reduced when co-administered with valproate. Serious skin reactions (such as Stevens-Johnson syndrome and toxic epidermal necrolysis) have been reported with concomitant lamotrigine and valproate administration. See lamotrigine package insert for details on lamotrigine dosing with concomitant valproate administration.

Phenobarbital

Valproate was found to inhibit the metabolism of phenobarbital. Co-administration of valproate (250 mg BID for 14 days) with phenobarbital to normal subjects (n = 6) resulted in a 50% increase in half-life and a 30% decrease in plasma clearance of phenobarbital (60 mg single-dose). The fraction of phenobarbital dose excreted unchanged increased by 50% in presence of valproate. There is evidence for severe CNS depression, with or without significant elevations of barbiturate or valproate serum concentrations. All patients receiving concomitant barbiturate therapy should be closely monitored for neurological toxicity. Serum barbiturate concentrations should be obtained, if possible, and the barbiturate dosage decreased, if appropriate. Primidone, which is metabolized to a barbiturate, may be involved in a similar interaction with valproate.

Phenytoin

Valproate displaces phenytoin from its plasma albumin binding sites and inhibits its hepatic metabolism. Co-administration of valproate (400 mg TID) with phenytoin (250 mg) in normal volunteers (n = 7) was associated with a 60% increase in the free fraction of phenytoin. Total plasma clearance and apparent volume of distribution of phenytoin increased 30% in the presence of valproate. Both the clearance and apparent volume of distribution of free phenytoin were reduced by 25%. In patients with epilepsy, there have been reports of breakthrough seizures occurring with the combination of valproate and phenytoin. The dosage of phenytoin should be adjusted as required by the clinical situation.

Propofol

The concomitant use of valproate and propofol may lead to increased blood levels of propofol. Reduce the dose of propofol when co-administering with valproate. Monitor patients closely for signs of increased sedation or cardiorespiratory depression.

Rufinamide

Based on a population pharmacokinetic analysis, rufinamide clearance was decreased by valproate. Rufinamide concentrations were increased by < 16% to 70%, dependent on concentration of valproate (with the larger increases being seen in pediatric patients at high doses or concentrations of valproate). Patients stabilized on rufinamide before being prescribed valproate should begin valproate therapy at a low dose, and titrate to a clinically effective dose [see Dosage and Administration (2.6) ] . Similarly, patients on valproate should begin at a rufinamide dose lower than 10 mg/kg per day (pediatric patients) or 400 mg per day (adults).

Tolbutamide

From in vitro experiments, the unbound fraction of tolbutamide was increased from 20% to 50% when added to plasma samples taken from patients treated with valproate. The clinical relevance of this displacement is unknown. Warfarin In an in vitro study, valproate increased the unbound fraction of warfarin by up to 32.6%. The therapeutic relevance of this is unknown; however, coagulation tests should be monitored if valproate therapy is instituted in patients taking anticoagulants. Zidovudine In six patients who were seropositive for HIV, the clearance of zidovudine (100 mg q8h) was decreased by 38% after administration of valproate (250 or 500 mg q8h); the half-life of zidovudine was unaffected. Drugs for Which Either No Interaction or a Likely Clinically Unimportant Interaction Has Been Observed Acetaminophen Valproate had no effect on any of the pharmacokinetic parameters of acetaminophen when it was concurrently administered to three epileptic patients. Clozapine In psychotic patients (n = 11), no interaction was observed when valproate was co-administered with clozapine. Lithium Co-administration of valproate (500 mg BID) and lithium carbonate (300 mg TID) to normal male volunteers (n = 16) had no effect on the steady-state kinetics of lithium.

Lorazepam

Concomitant administration of valproate (500 mg BID) and lorazepam (1 mg BID) in normal male volunteers (n = 9) was accompanied by a 17% decrease in the plasma clearance of lorazepam. Olanzapine No dose adjustment for olanzapine is necessary when olanzapine is administered concomitantly with valproate. Co-administration of valproate (500 mg BID) and olanzapine (5 mg) to healthy adults (n = 10) caused 15% reduction in Cmax and 35% reduction in AUC of olanzapine .

Oral Contraceptive Steroids

Administration of a single-dose of ethinyloestradiol (50 mcg)/levonorgestrel (250 mcg) to 6 women on valproate (200 mg BID) therapy for 2 months did not reveal any pharmacokinetic interaction.

7.3 Topiramate Concomitant administration of valproate and topiramate has been associated with hyperammonemia with and without encephalopathy <span class="opacity-50 text-xs">[see Contraindications (4) and Warnings and Precautions (5.6 , 5.9 , 5.10) ]</span> . Concomitant administration of topiramate with valproate has also been associated with hypothermia in patients who have tolerated either drug alone. It may be prudent to examine blood ammonia levels in patients in whom the onset of hypothermia has been reported <span class="opacity-50 text-xs">[see Warnings and Precautions (5.9 , 5.11) ]</span> .