MIRTAZAPINE: 28,691 Adverse Event Reports & Safety Profile

REMERON and REMERONSolTab contain mirtazapine. Mirtazapine has a tetracyclic chemical structure and belongs to the piperazino-azepine group of compounds. It is designated 1,2,3,4,10,14b-hexahydro-2-methylpyrazino [2,1-a] pyrido [2,3-c][2] benzazepine and has the empirical formula of C 17 H 19 N 3 . Its molecular weight is 265.35. The structural formula is the following and it is the racemic mixture: Mirtazapine is a white to creamy white crystalline powder which is practically insoluble in water. REMERON is available for oral administration as scored film-coated tablets containing 15 or 30 mg of mirtazapine Each tablet contains the following inactive ingredients: colloidal silicon dioxide anhydrous, corn starch, ferric oxide (yellow), hydroxypropyl cellulose, hypromellose, magnesium stearate, lactose monohydrate, polyethylene glycol 8000, and titanium dioxide.

The

30 mg tablets also contain ferric oxide (red). REMERONSolTab is available for oral administration as an orally disintegrating tablet containing 15, 30, or 45 mg of mirtazapine. REMERONSolTab also contains the following inactive ingredients: aspartame, citric acid anhydrous fine granular, crospovidone, hypromellose, magnesium stearate, mannitol, granular mannitol 2080, microcrystalline cellulose, natural and artificial orange flavor, polymethacrylate (Eudragit E100), povidone, sodium bicarbonate, and sugar spheres (composed of starch and sucrose).

Chemical

Structure

INDICATIONS AND USAGE Mirtazapine tablets, USP are indicated for the treatment of major depressive disorder. The efficacy of mirtazapine tablets, USP in the treatment of major depressive disorder was established in six week controlled trials of outpatients whose diagnoses corresponded most closely to the Diagnostic and Statistical Manual of Mental Disorders – 3rd edition (DSM-III) category of major depressive disorder (see CLINICAL PHARMACOLOGY ). A major depressive episode (DSM-IV) implies a prominent and relatively persistent (nearly every day for at least 2 weeks) depressed or dysphoric mood that usually interferes with daily functioning, and includes at least five of the following nine symptoms: depressed mood, loss of interest in usual activities, significant change in weight and/or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, a suicide attempt or suicidal ideation. The effectiveness of mirtazapine tablets, USP in hospitalized depressed patients has not been adequately studied. The efficacy of mirtazapine tablets, USP in maintaining a response in patients with major depressive disorder for up to 40 weeks following 8 to 12 weeks of initial open-label treatment was demonstrated in a placebo-controlled trial. Nevertheless, the physician who elects to use mirtazapine tablets, USP for extended periods should periodically re-evaluate the long-term usefulness of the drug for the individual patient (see CLINICAL PHARMACOLOGY ).

DOSAGE AND ADMINISTRATION Initial Treatment The recommended starting dose for mirtazapine tablets is 15 mg/day, administered in a single dose, preferably in the evening prior to sleep. In the controlled clinical trials establishing the efficacy of mirtazapine in the treatment of major depressive disorder, the effective dose range was generally 15 to 45 mg/day. While the relationship between dose and satisfactory response in the treatment of major depressive disorder for mirtazapine tablets has not been adequately explored, patients not responding to the initial 15 mg dose may benefit from dose increases up to a maximum of 45 mg/day. Mirtazapine tablets has an elimination half-life of approximately 20 to 40 hours; therefore, dose changes should not be made at intervals of less than one to two weeks in order to allow sufficient time for evaluation of the therapeutic response to a given dose. Elderly and Patients with Renal or Hepatic Impairment The clearance of mirtazapine is reduced in elderly patients and in patients with moderate to severe renal or hepatic impairment. Consequently, the prescriber should be aware that plasma mirtazapine levels may be increased in these patient groups, compared to levels observed in younger adults without renal or hepatic impairment (see PRECAUTIONS and CLINICAL PHARMACOLOGY ).

Maintenance/Extended

Treatment It is generally agreed that acute episodes of depression require several months or longer of sustained pharmacological therapy beyond response to the acute episode. Systematic evaluation of mirtazapine tablets has demonstrated that its efficacy in major depressive disorder is maintained for periods of up to 40 weeks following 8 to 12 weeks of initial treatment at a dose of 15 to 45 mg/day (see CLINICAL PHARMACOLOGY ). Based on these limited data, it is unknown whether or not the dose of mirtazapine tablets needed for maintenance treatment is identical to the dose needed to achieve an initial response. Patients should be periodically reassessed to determine the need for maintenance treatment and the appropriate dose for such treatment. Switching a Patient To or From a Monoamine Oxidase Inhibitor (MAOI) Intended to Treat Psychiatric Disorders At least 14 days should elapse between discontinuation of an MAOI intended to treat psychiatric disorders and initiation of therapy with mirtazapine tablets. Conversely, at least 14 days should be allowed after stopping mirtazapine tablets before starting an MAOI intended to treat psychiatric disorders (see CONTRAINDICATIONS ). Use of Mirtazapine Tablets With Other MAOIs, Such as Linezolid or Methylene Blue Do not start mirtazapine tablets in a patient who is being treated with linezolid or intravenous methylene blue because there is an increased risk of serotonin syndrome. In a patient who requires more urgent treatment of a psychiatric condition, other interventions, including hospitalization, should be considered (see CONTRAINDICATIONS ). In some cases, a patient already receiving therapy with mirtazapine may require urgent treatment with linezolid or intravenous methylene blue. If acceptable alternatives to linezolid or intravenous methylene blue treatment are not available and the potential benefits of linezolid or intravenous methylene blue treatment are judged to outweigh the risks of serotonin syndrome in a particular patient, Mirtazapine tablets should be stopped promptly, and linezolid or intravenous methylene blue can be administered. The patient should be monitored for symptoms of serotonin syndrome for 2 weeks or until 24 hours after the last dose of linezolid or intravenous methylene blue, whichever comes first. Therapy with mirtazapine tablets may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue (see WARNINGS ). The risk of administering methylene blue by non-intravenous routes (such as oral tablets or by local injection) or in intravenous doses much lower than 1 mg/kg with mirtazapine tablets is unclear. The clinician should, nevertheless, be aware of the possibility of emergent symptoms of serotonin syndrome with such use (see WARNINGS ). Discontinuation of Mirtazapine Tablets, USP Treatment Symptoms associated with the discontinuation or dose reduction of mirtazapine tablets have been reported. Patients should be monitored for these and other symptoms when discontinuing treatment or during dosage reduction. A gradual reduction in the dose over several weeks, rather than abrupt cessation, is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, dose titration should be managed on the basis of the patient’s clinical response (see PRECAUTIONS and ADVERSE REACTIONS ). Information for Patients Patients should be advised that taking mirtazapine tablets can cause mild pupillary dilation, which in susceptible individuals, can lead to an episode of angle-closure glaucoma. Pre- existing glaucoma is almost always open-angle glaucoma because angle-closure glaucoma, when diagnosed, can be treated definitively with iridectomy. Open-angle glaucoma is not a risk factor for angle-closure glaucoma. Patients may wish to be examined to determine whether they are susceptible to angle-closure, and have a prophylactic procedure (e.g., iridectomy), if they are susceptible.

Mirtazapine orally disintegrating tablets are contraindicated in patients:

• Taking, or within 14 days of stopping, MAOIs (including the MAOIs linezolid and intravenous methylene blue) because of an increased risk of serotonin syndrome [see Warnings and Precautions (5.3) , Drug Interactions (7) ].
• With a known hypersensitivity to mirtazapine or to any of the excipients in mirtazapine orally disintegrating tablets. Severe skin reactions, including drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome, bullous dermatitis, erythema multiforme and toxic epidermal necrolysis have been reported following the use of mirtazapine orally disintegrating tablets [see Warnings and Precautions (5.6) , Adverse Reactions (6.2) ].
• Concomitant use of monoamine oxidase inhibitors (MAOIs) or use within 14 days of stopping MAOIs. ( 2.4 , 4 , 7 )
• Known hypersensitivity to mirtazapine or any of the excipients in mirtazapine orally disintegrating tablets. ( 4 )

ADVERSE REACTIONS Associated with Discontinuation of Treatment Approximately 16% of the 453 patients who received mirtazapine tablets in US 6-week controlled clinical trials discontinued treatment due to an adverse experience, compared to 7% of the 361 placebo-treated patients in those studies. The most common events (≥1%) associated with discontinuation and considered to be drug related (i.e., those events associated with dropout at a rate at least twice that of placebo) are included in Table 2.

Table

2 : Common Adverse Events Associated with Discontinuation of Treatment in 6-week US Mirtazapine Tablets Trials Adverse E vent Percentage of Patients Discontinuing with Adverse Even t Mirtazapine Tablets (n=453 ) Placebo (n=3 61)

Somnolence

10.4% 2.2% Nausea 1.5% 0% Commonly Observed Adverse Events in US Controlled Clinical Trials The most commonly observed adverse events associated with the use of mirtazapine tablets (incidence of 5% or greater) and not observed at an equivalent incidence among placebo-treated patients (mirtazapine tablets incidence at least twice that for placebo) are listed in Table 3.

Table

3: Common Treatment-emergent Adverse Events Associated with the Use of Mirtazapine Tablets in 6-week US Trials Adverse Eve nt Percentage of Patients Reporting Adverse Even t Mirtazapine Tablets (n=45 3) Placebo (n=3 61)

Somnolence

54% 18% Increased Appetite 17% 2% Weight Gain 12% 2% Dizziness 7% 3% Adverse Events Occurring at an Incidence of 1% or More Among Mirtazapine Tablet-treated Patients Table 4 enumerates adverse events that occurred at an incidence of 1% or more, and were more frequent than in the placebo group, among mirtazapine tablet-treated patients who participated in short-term US placebo-controlled trials in which patients were dosed in a range of 5 to 60 mg/day. This table shows the percentage of patients in each group who had at least one episode of an event at some time during their treatment. Reported adverse events were classified using a standard COSTART-based dictionary terminology. The prescriber should be aware that these figures cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those which prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other investigations involving different treatments, uses, and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the side-effect incidence rate in the population studied.

Table

4: Incidence of Adverse Clinical Experiences * (≥ 1%) in Short-term US Controlled Studies Body System Adverse Clinical Experience Mirtazapine Tablets (n=453) Placebo (n=361) Body as a Whole Asthenia 8% 5% Flu Syndrome 5% 3% Back Pain 2% 1% Digestive System Dry Mouth 25% 15% Increased Appetite 17% 2% Constipation 13% 7% Metabolic and Nutritional Disorders Weight Gain 12% 2% Peripheral Edema 2% 1% Edema 1% 0% Musculoskeletal System Myalgia 2% 1% Nervous System Somnolence 54% 18% Dizziness 7% 3% Abnormal Dreams 4% 1% Thinking Abnormal 3% 1% Tremor 2% 1% Confusion 2% 0% Respiratory System Dyspnea 1% 0% Urogenital System Urinary Frequency 2% 1% * Events reported by at least 1% of patients treated with mirtazapine tablets are included, except the following events, which had an incidence on placebo greater than or equal to mirtazapine tablets: headache, infection, pain, chest pain, palpitation, tachycardia, postural hypotension, nausea, dyspepsia, diarrhea, flatulence, insomnia, nervousness, libido decreased, hypertonia, pharyngitis, rhinitis, sweating, amblyopia, tinnitus, taste perversion.

Ecg

Changes The electrocardiograms for 338 patients who received mirtazapine tablets and 261 patients who received placebo in 6-week, placebo-controlled trials were analyzed. Prolongation in QT c ≥500 msec was not observed among mirtazapine-treated patients; mean change in QT c was +1.6 msec for mirtazapine and -3.1 msec for placebo. Mirtazapine was associated with a mean increase in heart rate of 3.4 bpm, compared to 0.8 bpm for placebo. The clinical significance of these changes is unknown. The effect of mirtazapine on QTc interval was assessed in a clinical randomized trial with placebo and positive (moxifloxacin) controls involving 54 healthy volunteers using exposure response analysis. This trial showed a positive relationship between mirtazapine concentrations and prolongation of the QTc interval. However, the degree of QT prolongation observed with both 45 mg (therapeutic) and 75 mg (supratherapeutic) doses of mirtazapine was not at a level generally considered to be clinically meaningful.

Other Adverse Events Observed

During the Premarketing Evaluation of Mirtazapine Tablets During its premarketing assessment, multiple doses of mirtazapine tablets were administered to 2796 patients in clinical studies. The conditions and duration of exposure to mirtazapine varied greatly, and included (in overlapping categories) open and double-blind studies, uncontrolled and controlled studies, inpatient and outpatient studies, fixed-dose and titration studies. Untoward events associated with this exposure were recorded by clinical investigators using terminology of their own choosing. Consequently, it is not possible to provide a meaningful estimate of the proportion of individuals experiencing adverse events without first grouping similar types of untoward events into a smaller number of standardized event categories. In the tabulations that follow, reported adverse events were classified using a standard COSTART-based dictionary terminology. The frequencies presented, therefore, represent the proportion of the 2796 patients exposed to multiple doses of mirtazapine tablets who experienced an event of the type cited on at least one occasion while receiving mirtazapine tablets. All reported events are included except those already listed in Table 4, those adverse experiences subsumed under COSTART terms that are either overly general or excessively specific so as to be uninformative, and those events for which a drug cause was very remote. It is important to emphasize that, although the events reported occurred during treatment with mirtazapine tablets, they were not necessarily caused by it. Events are further categorized by body system and listed in order of decreasing frequency according to the following definitions: frequent adverse events are those occurring on one or more occasions in at least 1/100 patients; infrequent adverse events are those occurring in 1/100 to 1/1,000 patients; rare events are those occurring in fewer than 1/1,000 patients. Only those events not already listed in Table 4 appear in this listing. Events of major clinical importance are also described in the WARNINGS and PRECAUTIONS sections. Body as a Whole Frequent : malaise, abdominal pain, abdominal syndrome acute; infrequent: chills, fever, face edema, ulcer, photosensitivity reaction, neck rigidity, neck pain, abdomen enlarged; rare : cellulitis, chest pain substernal.

Cardiovascular System

Frequent : hypertension, vasodilatation; infrequent : angina pectoris, myocardial infarction, bradycardia, ventricular extrasystoles, syncope, migraine, hypotension; rare : atrial arrhythmia, bigeminy, vascular headache, pulmonary embolus, cerebral ischemia, cardiomegaly, phlebitis, left heart failure.

Digestive System

Frequent : vomiting, anorexia; infrequent : eructation, glossitis, cholecystitis, nausea and vomiting, gum hemorrhage, stomatitis, colitis, liver function tests abnormal; rare : tongue discoloration, ulcerative stomatitis, salivary gland enlargement, increased salivation, intestinal obstruction, pancreatitis, aphthous stomatitis, cirrhosis of liver, gastritis, gastroenteritis, oral moniliasis, tongue edema.

Endocrine System

Rare: goiter, hypothyroidism. Hemic and Lymphatic System Rare: lymphadenopathy, leukopenia, petechia, anemia, thrombocytopenia, lymphocytosis, pancytopenia. Metabolic and Nutritional Disorders Frequent : thirst; infrequent : dehydration, weight loss; rare : gout, SGOT increased, healing abnormal, acid phosphatase increased, SGPT increased, diabetes mellitus, hyponatremia.

Musculoskeletal System

Frequent : myasthenia, arthralgia; infrequent : arthritis, tenosynovitis; rare : pathologic fracture, osteoporosis fracture, bone pain, myositis, tendon rupture, arthrosis, bursitis.

Nervous System

Frequent : hypesthesia, apathy, depression, hypokinesia, vertigo, twitching, agitation, anxiety, amnesia, hyperkinesia, paresthesia; infrequent : ataxia, delirium, delusions, depersonalization, dyskinesia, extrapyramidal syndrome, libido increased, coordination abnormal, dysarthria, hallucinations, manic reaction, neurosis, dystonia, hostility, reflexes increased, emotional lability, euphoria, paranoid reaction; rare: aphasia, nystagmus, akathisia (psychomotor restlessness), stupor, dementia, diplopia, drug dependence, paralysis, grand mal convulsion, hypotonia, myoclonus, psychotic depression, withdrawal syndrome, serotonin syndrome.

Respiratory System

Frequent : cough increased, sinusitis; infrequent : epistaxis, bronchitis, asthma, pneumonia; rare : asphyxia, laryngitis, pneumothorax, hiccup. Skin and Appendages Frequent : pruritus, rash; infrequent : acne, exfoliative dermatitis, dry skin, herpes simplex, alopecia; rare : urticaria, herpes zoster, skin hypertrophy, seborrhea, skin ulcer.

Special Senses

Infrequent : eye pain, abnormality of accommodation, conjunctivitis, deafness, keratoconjunctivitis, lacrimation disorder, angle-closure glaucoma, hyperacusis, ear pain; rare: blepharitis, partial transitory deafness, otitis media, taste loss, parosmia.

Urogenital System

Frequent : urinary tract infection; infrequent : kidney calculus, cystitis, dysuria, urinary incontinence, urinary retention, vaginitis, hematuria, breast pain, amenorrhea, dysmenorrhea, leukorrhea, impotence; rare : polyuria, urethritis, metrorrhagia, menorrhagia, abnormal ejaculation, breast engorgement, breast enlargement, urinary urgency.

Other Adverse Events Observed During

Postmarketing Evaluation of Mirtazapine Tablets Adverse events reported since market introduction, which were temporally (but not necessarily causally) related to mirtazapine therapy, include cases of the ventricular arrhythmia Torsades de Pointes. In the majority of these cases, however, concomitant drugs were implicated. Cases of severe skin reactions, including Stevens-Johnson syndrome, bullous dermatitis, erythema multiforme and toxic epidermal necrolysis have also been reported. Increased creatine kinase blood levels and rhabdomyolysis have also been reported.

AND PRECAUTIONS Agranulocytosis : If sore throat, fever, stomatitis or signs of infection occur, along with a low white blood cell count, treatment with mirtazapine orally disintegrating tablets should be discontinued and the patient should be closely monitored. ( 5.2 )

Serotonin

Syndrome : Increased risk when co-administered with other serotonergic drugs (e.g., SSRI, SNRI, triptans), but also when taken alone. If it occurs, discontinue mirtazapine orally disintegrating tablets and initiate supportive treatment. ( 2.4 , 4 , 5.3 , 7 ) Angle-Closure Glaucoma : Angle closure glaucoma has occurred in patients with untreated anatomically narrow angles treated with antidepressants. ( 5.4 ) QT Prolongation : Use mirtazapine orally disintegrating tablets with caution in patients with risk factors for QT prolongation. ( 5.5 , 7 )

Drug

Reaction with Eosinophilia and System Symptoms (DRESS): Discontinue mirtazapine orally disintegrating tablets if DRESS is suspected. ( 5.6 )

Increased Appetite/Weight

Gain : Mirtazapine orally disintegrating tablets have been associated with increased appetite and weight gain. ( 5.7 ) Somnolence : May impair judgment, thinking and/or motor skills. Use with caution when engaging in activities requiring alertness, such as driving or operating machinery. ( 5.8 , 7 ) Activation of Mania/Hypomania : Screen patients for bipolar disorder prior to initiating treatment. ( 2.3 , 5.9 ) Seizures : Use with caution in patients with a seizure disorder. ( 5.10 )

Elevated

Cholesterol/Triglycerides : Has been reported with mirtazapine use. ( 5.11 ) Hyponatremia : May occur as a result of treatment with serotonergic antidepressants, including mirtazapine orally disintegrating tablets. ( 5.12 )

Transaminase

Elevations : Clinically significant elevations have occurred. Use with caution in patients with impaired hepatic function. ( 5.13 )

5.1 Suicidal Thoughts and Behaviors in Adolescents and Young Adults In pooled analyses of placebo-controlled trials of antidepressant drugs (SSRIs and other antidepressant classes) that included approximately 77,000 adult patients and 4,500 pediatric patients, the incidence of suicidal thoughts and behaviors in antidepressant-treated patients age 24 years and younger was greater than in placebo-treated patients. There was considerable variation in risk of suicidal thoughts and behaviors among drugs, but there was an increased risk identified in young patients for most drugs studied. There were differences in absolute risk of suicidal thoughts and behaviors across the different indications, with the highest incidence in patients with MDD. The drug-placebo differences in the number of cases of suicidal thoughts and behaviors per 1000 patients treated are provided in Table 1.

Table

1: Risk Differences of the Number of Patients with Suicidal Thoughts and Behavior in the Pooled Placebo-Controlled Trials of Antidepressants in Pediatric and Adult Patients Age Range Drug-Placebo Difference in Number of Patients with Suicidal Thoughts or Behaviors per 1000 Patients Treated Increases Compared to Placebo <18 years old 14 additional patients 18 to 24 years old 5 additional patients Decreases Compared to Placebo 25 to 64 years old 1 fewer patient ≥65 years old 6 fewer patients It is unknown whether the risk of suicidal thoughts and behaviors in children, adolescents, and young adults extends to longer-term use, i.e., beyond four months. However, there is substantial evidence from placebo-controlled maintenance trials in adults with MDD that antidepressants delay the recurrence of depression and that depression itself is a risk factor for suicidal thoughts and behaviors. Monitor all antidepressant-treated patients for any indication of clinical worsening and emergence of suicidal thoughts and behaviors, especially during the initial few months of drug therapy, and at times of dosage changes. Counsel family members or caregivers of patients to monitor for changes in behavior and to alert the healthcare provider. Consider changing the therapeutic regimen, including possibly discontinuing mirtazapine orally disintegrating tablets, in patients whose depression is persistently worse, or who are experiencing emergent suicidal thoughts or behaviors.

5.2 Agranulocytosis In premarketing clinical trials, 2 (1 with Sjögren&apos;s Syndrome) out of 2796 patients treated with mirtazapine developed agranulocytosis [absolute neutrophil count (ANC) &lt;500/mm 3 with associated signs and symptoms, e.g., fever, infection, etc.] and a third patient developed severe neutropenia (ANC &lt;500/mm 3 without any associated symptoms). For these 3 patients, onset of severe neutropenia was detected on days 61, 9, and 14 of treatment, respectively.

All

3 patients recovered after mirtazapine was stopped. If a patient develops a sore throat, fever, stomatitis, or other signs of infection, along with a low white blood cell (WBC) count, treatment with mirtazapine orally disintegrating tablets should be discontinued and the patient should be closely monitored.

5.3 Serotonin Syndrome Serotonergic antidepressants, including mirtazapine orally disintegrating tablets, can precipitate serotonin syndrome, a potentially life-threatening condition. The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. John&apos;s Wort) and with drugs that impair metabolism of serotonin, i.e., MAOIs <span class="opacity-50 text-xs">[see Contraindications (4) , Drug Interactions (7) ]</span> . Serotonin syndrome can also occur when these drugs are used alone. Serotonin syndrome signs and symptoms may include mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). The concomitant use of mirtazapine orally disintegrating tablets with MAOIs is contraindicated. In addition, do not initiate mirtazapine orally disintegrating tablets in a patient being treated with MAOIs such as linezolid or intravenous methylene blue. No reports involved the administration of methylene blue by other routes (such as oral tablets or local tissue injection). If it is necessary to initiate treatment with an MAOI such as linezolid or intravenous methylene blue in a patient taking mirtazapine orally disintegrating tablets, discontinue mirtazapine orally disintegrating tablets before initiating treatment with the MAOI <span class="opacity-50 text-xs">[see Contraindications (4) , Drug Interactions (7) ]</span>. Monitor all patients taking mirtazapine orally disintegrating tablets for the emergence of serotonin syndrome. Discontinue treatment with mirtazapine orally disintegrating tablets and any concomitant serotonergic agents immediately if the above symptoms occur, and initiate supportive symptomatic treatment. If concomitant use of mirtazapine orally disintegrating tablets with other serotonergic drugs is clinically warranted, inform patients of the increased risk for serotonin syndrome and monitor for symptoms.

5.4 Angle-Closure Glaucoma The pupillary dilation that occurs following use of many antidepressant drugs, including mirtazapine orally disintegrating tablets, may trigger an angle-closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy.

5.5 QT Prolongation and Torsades de Pointes The effect of mirtazapine on QTc interval was assessed in a clinical randomized trial with placebo and positive (moxifloxacin) controls involving 54 healthy volunteers using exposure response analysis. This trial showed a positive relationship between mirtazapine concentrations and prolongation of the QTc interval. However, the degree of QT prolongation observed with both 45 mg and 75 mg (1.67 times the maximum recommended daily dose) doses of mirtazapine was not at a level generally considered to be clinically meaningful. During postmarketing use of mirtazapine, cases of QT prolongation, Torsades de Pointes, ventricular tachycardia, and sudden death, have been reported <span class="opacity-50 text-xs">[see Adverse Reactions (6.1 , 6.2 )]</span> . The majority of reports occurred in association with overdose or in patients with other risk factors for QT prolongation, including concomitant use of QTc-prolonging medicines <span class="opacity-50 text-xs">[see Drug Interactions (7) and Overdosage (10) ]</span> . Exercise caution when mirtazapine orally disintegrating tablets are prescribed in patients with known cardiovascular disease or family history of QT prolongation, and in concomitant use with other drugs thought to prolong the QTc interval.

5.6 Drug Reaction with Eosinophilia and System Symptoms (DRESS)

Drug

Reaction with eosinophilia and systemic symptoms (DRESS) has been reported with postmarketing use of mirtazapine. DRESS may present with a cutaneous reaction (such as rash or exfoliative dermatitis), eosinophilia, fever, and/or lymphadenopathy with systemic complications such as hepatitis, nephritis, pneumonitis, myocarditis, and/or pericarditis. DRESS is sometimes fatal. Discontinue mirtazapine orally disintegrating tablets immediately if DRESS is suspected and institute appropriate treatment [see Contraindications (4) , Adverse Reactions (6.2) ].

5.7 Increased Appetite and Weight Gain In U.S. controlled clinical studies, appetite increase was reported in 17% of patients treated with mirtazapine, compared to 2% for placebo. In these same trials, weight gain of ≥7% of body weight was reported in 7.5% of patients treated with mirtazapine, compared to 0% for placebo. In a pool of premarketing U.S. clinical studies, including many patients for long-term, open-label treatment, 8% of patients receiving mirtazapine discontinued for weight gain. In an 8-week-long pediatric clinical trial of doses between 15 to 45 mg/day, 49% of mirtazapine-treated pediatric patients had a weight gain of at least 7%, compared to 5.7% of placebo-treated patients. The safety and effectiveness of mirtazapine orally disintegrating tablets in pediatric patients with MDD have not been established <span class="opacity-50 text-xs">[see Use in Specific Populations (8.4) ]</span> .

5.8 Somnolence In U.S. controlled studies, somnolence was reported in 54% of patients treated with mirtazapine, compared to 18% for placebo. In these studies, somnolence resulted in discontinuation for 10.4% of mirtazapine-treated patients, compared to 2.2% for placebo. It is unclear whether tolerance develops to the somnolent effect of mirtazapine orally disintegrating tablets. Because of the potentially significant effects of mirtazapine orally disintegrating tablets on impairment of performance, caution patients about engaging in activities that require alertness, including operating hazardous machinery and motor vehicles, until they are reasonably certain that mirtazapine orally disintegrating tablets does not affect them adversely. The concomitant use of benzodiazepines and alcohol with mirtazapine orally disintegrating tablets should be avoided <span class="opacity-50 text-xs">[see Drug Interactions (7) ]</span> .

5.9 Activation of Mania or Hypomania In patients with bipolar disorder, treating a depressive episode with mirtazapine orally disintegrating tablets or another antidepressant may precipitate a mixed/manic episode. In controlled clinical trials, patients with bipolar disorder were generally excluded; however, symptoms of mania or hypomania were reported in 0.2% of patients treated with mirtazapine. Prior to initiating treatment with mirtazapine orally disintegrating tablets, screen patients for any personal or family history of bipolar disorder, mania, or hypomania.

5.10 Seizures Mirtazapine orally disintegrating tablets have not been systematically evaluated in patients with seizure disorders. In premarketing clinical trials, 1 seizure was reported among the 2796 U.S. and non-U.S. patients treated with mirtazapine. Mirtazapine orally disintegrating tablets should be prescribed with caution in patients with a seizure disorder.

5.11 Elevated Cholesterol and Triglycerides In U.S. controlled studies, nonfasting cholesterol increases to ≥20% above the upper limits of normal were observed in 15% of patients treated with mirtazapine, compared to 7% for placebo. In these same studies, nonfasting triglyceride increases to ≥500 mg/dL were observed in 6% of patients treated with mirtazapine, compared to 3% for placebo.

5.12 Hyponatremia Hyponatremia may occur as a result of treatment with serotonergic antidepressants, including mirtazapine orally disintegrating tablets. Cases with serum sodium lower than 110 mmol/L have been reported. Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which may lead to falls. Signs and symptoms associated with more severe or acute cases have included hallucination, syncope, seizure, coma, respiratory arrest, and death. In many cases, this hyponatremia appears to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). In patients with symptomatic hyponatremia, discontinue mirtazapine orally disintegrating tablets and institute appropriate medical intervention. Elderly patients, patients taking diuretics, and those who are volume-depleted may be at greater risk of developing hyponatremia <span class="opacity-50 text-xs">[see Use in Specific Populations (8.5) ]</span> .

5.13 Transaminase Elevations Clinically significant ALT (SGPT) elevations (≥3 times the upper limit of the normal range) were observed in 2.0% (8/424) of patients treated with mirtazapine in a pool of short-term, U.S. controlled trials, compared to 0.3% (1/328) of placebo patients. While some patients were discontinued for the ALT increases, in other cases, the enzyme levels returned to normal despite continued mirtazapine treatment. Mirtazapine orally disintegrating tablets should be used with caution in patients with impaired hepatic function <span class="opacity-50 text-xs">[see Use in Specific Populations (8.6) , Clinical Pharmacology (12.3) ]</span> .

5.14 Discontinuation Syndrome There have been reports of adverse reactions upon the discontinuation of mirtazapine orally disintegrating tablets (particularly when abrupt), including but not limited to the following: dizziness, abnormal dreams, sensory disturbances (including paresthesia and electric shock sensations), agitation, anxiety, fatigue, confusion, headache, tremor, nausea, vomiting, and sweating, or other symptoms which may be of clinical significance. A gradual reduction in the dosage, rather than an abrupt cessation, is recommended <span class="opacity-50 text-xs">[see Dosage and Administration (2.6) ]</span>.

5.15 Use in Patients with Concomitant Illness Mirtazapine orally disintegrating tablets have not been systematically evaluated or used to any appreciable extent in patients with a recent history of myocardial infarction or other significant heart disease. Mirtazapine was associated with significant orthostatic hypotension in early clinical pharmacology trials with normal volunteers. Orthostatic hypotension was infrequently observed in clinical trials with depressed patients <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span> . Mirtazapine orally disintegrating tablets should be used with caution in patients with known cardiovascular or cerebrovascular disease that could be exacerbated by hypotension (history of myocardial infarction, angina, or ischemic stroke) and conditions that would predispose patients to hypotension (dehydration, hypovolemia, and treatment with antihypertensive medication).

5.16 Risks in Patients with Phenylketonuria Phenylalanine can be harmful to patients with phenylketonuria (PKU). Mirtazapine orally disintegrating tablets contain phenylalanine, a component of aspartame. Mirtazapine orally disintegrating tablets contain the following amount of phenylalanine: 3.22 mg per 15 mg orally disintegrating tablet, 6.44 mg per 30 mg orally disintegrating tablet, and 9.66 mg per 45 mg orally disintegrating tablet. Before prescribing mirtazapine orally disintegrating tablets to a patient with PKU, consider the combined daily amount of phenylalanine from all sources, including mirtazapine orally disintegrating tablets.

PRECAUTIONS General Discontinuation Symptoms There have been reports of adverse reactions upon the discontinuation of mirtazapine tablets, USP (particularly when abrupt), including but not limited to the following: dizziness, abnormal dreams, sensory disturbances (including paresthesia and electric shock sensations), agitation, anxiety, fatigue, confusion, headache, tremor, nausea, vomiting, and sweating, or other symptoms which may be of clinical significance. The majority of the reported cases are mild and self-limiting. Even though these have been reported as adverse reactions, it should be realized that these symptoms may be related to underlying disease. Patients currently taking mirtazapine tablets should NOT discontinue treatment abruptly, due to risk of discontinuation symptoms. At the time that a medical decision is made to discontinue treatment with mirtazapine tablets, a gradual reduction in the dose, rather than an abrupt cessation, is recommended.

Akathisia/Psychomotor

Restlessness The use of antidepressants has been associated with the development of akathisia, characterized by a subjectively unpleasant or distressing restlessness and need to move, often accompanied by an inability to sit or stand still. This is most likely to occur within the first few weeks of treatment. In patients who develop these symptoms, increasing the dose may be detrimental.

Hyponatremia

Hyponatremia has been reported very rarely with the use of mirtazapine. Caution should be exercised in patients at risk, such as elderly patients or patients concomitantly treated with medications known to cause hyponatremia. Somnolence In US controlled studies, somnolence was reported in 54% of patients treated with mirtazapine tablets, compared to 18% for placebo and 60% for amitriptyline. In these studies, somnolence resulted in discontinuation for 10.4% of mirtazapine tablets-treated patients, compared to 2.2% for placebo. It is unclear whether or not tolerance develops to the somnolent effects of mirtazapine tablets. Because of the potentially significant effects of mirtazapine tablets on impairment of performance, patients should be cautioned about engaging in activities requiring alertness until they have been able to assess the drug’s effect on their own psychomotor performance (see PRECAUTIONS: Information for Patients ). Dizziness In US controlled studies, dizziness was reported in 7% of patients treated with mirtazapine tablets, compared to 3% for placebo and 14% for amitriptyline. It is unclear whether or not tolerance develops to the dizziness observed in association with the use of mirtazapine tablets.

Increased Appetite/Weight

Gain In US controlled studies, appetite increase was reported in 17% of patients treated with mirtazapine tablets, compared to 2% for placebo and 6% for amitriptyline. In these same trials, weight gain of ≥7% of body weight was reported in 7.5% of patients treated with mirtazapine, compared to 0% for placebo and 5.9% for amitriptyline. In a pool of premarketing US studies, including many patients for long-term, open-label treatment, 8% of patients receiving mirtazapine tablets discontinued for weight gain. In an 8-week-long pediatric clinical trial of doses between 15 to 45 mg/day, 49% of mirtazapine treated patients had a weight gain of at least 7%, compared to 5.7% of placebo-treated patients (see PRECAUTIONS: Pediatric Use ). Cholesterol/Triglycerides In US controlled studies, nonfasting cholesterol increases to ≥20% above the upper limits of normal were observed in 15% of patients treated with mirtazapine tablets, compared to 7% for placebo and 8% for amitriptyline. In these same studies, nonfasting triglyceride increases to ≥500 mg/dL were observed in 6% of patients treated with mirtazapine, compared to 3% for placebo and 3% for amitriptyline.

Transaminase Elevations

Clinically significant ALT (SGPT) elevations (≥3 times the upper limit of the normal range) were observed in 2.0% (8/424) of patients exposed to mirtazapine tablets in a pool of short-term US controlled trials, compared to 0.3% (1/328) of placebo patients and 2.0% (3/181) of amitriptyline patients. Most of these patients with ALT increases did not develop signs or symptoms associated with compromised liver function. While some patients were discontinued for the ALT increases, in other cases, the enzyme levels returned to normal despite continued mirtazapine treatment. Mirtazapine tablets should be used with caution in patients with impaired hepatic function (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION ). Activation of Mania/Hypomania Mania/hypomania occurred in approximately 0.2% (3/1299 patients) of mirtazapine tablet-treated patients in US studies. Although the incidence of mania/hypomania was very low during treatment with mirtazapine, it should be used carefully in patients with a history of mania/hypomania. Seizure In premarketing clinical trials, only one seizure was reported among the 2796 US and non-US patients treated with mirtazapine tablets. However, no controlled studies have been carried out in patients with a history of seizures. Therefore, care should be exercised when mirtazapine is used in these patients. Use in Patients with Concomitant Illness Clinical experience with mirtazapine tablets in patients with concomitant systemic illness is limited. Accordingly, care is advisable in prescribing mirtazapine for patients with diseases or conditions that affect metabolism or hemodynamic responses. Mirtazapine tablets have not been systematically evaluated or used to any appreciable extent in patients with a recent history of myocardial infarction or other significant heart disease. Mirtazapine tablets were associated with significant orthostatic hypotension in early clinical pharmacology trials with normal volunteers. Orthostatic hypotension was infrequently observed in clinical trials with depressed patients. Mirtazapine tablets should be used with caution in patients with known cardiovascular or cerebrovascular disease that could be exacerbated by hypotension (history of myocardial infarction, angina, or ischemic stroke) and conditions that would predispose patients to hypotension (dehydration, hypovolemia, and treatment with antihypertensive medication). Mirtazapine clearance is decreased in patients with moderate [glomerular filtration rate (GFR) =11 to 39 mL/min/1.73 m 2 ] and severe [GFR <10 mL/min/1.73 m 2 ] renal impairment, and also in patients with hepatic impairment. Caution is indicated in administering mirtazapine tablets to such patients (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION ). Information for Patients Prescribers or other health professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with mirtazapine tablets and should counsel them in its appropriate use. A patient Medication Guide about “Antidepressant Medicines, Depression and other Serious Mental Illnesses, and Suicidal Thoughts or Actions” is available for mirtazapine tablets. The prescriber or health professional should instruct patients, their families, and their caregivers to read the Medication Guide and should assist them in understanding its contents. Patients should be given the opportunity to discuss the contents of the Medication Guide and to obtain answers to any questions they may have. The complete text of the Medication Guide is reprinted at the end of this document. Patients should be advised of the following issues and asked to alert their prescriber if these occur while taking mirtazapine tablets.

Clinical

Worsening and Suicide Risk Patients, their families, and their caregivers should be encouraged to be alert to the emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, mania, other unusual changes in behavior, worsening of depression, and suicidal ideation, especially early during antidepressant treatment and when the dose is adjusted up or down. Families and caregivers of patients should be advised to look for the emergence of such symptoms on a day-to-day basis, since changes may be abrupt. Such symptoms should be reported to the patient's prescriber or health professional, especially if they are severe, abrupt in onset, or were not part of the patient's presenting symptoms. Symptoms such as these may be associated with an increased risk for suicidal thinking and behavior and indicate a need for very close monitoring and possibly changes in the medication.

Agranulocytosis

Patients who are to receive mirtazapine tablets should be warned about the risk of developing agranulocytosis. Patients should be advised to contact their physician if they experience any indication of infection such as fever, chills, sore throat, mucous membrane ulceration, or other possible signs of infection. Particular attention should be paid to any flu-like complaints or other symptoms that might suggest infection. Interference with Cognitive and Motor Performance Mirtazapine tablets may impair judgment, thinking, and particularly, motor skills, because of its prominent sedative effect. The drowsiness associated with mirtazapine use may impair a patient’s ability to drive, use machines, or perform tasks that require alertness. Thus, patients should be cautioned about engaging in hazardous activities until they are reasonably certain that mirtazapine tablet therapy does not adversely affect their ability to engage in such activities.

Completing

Course of Therapy While patients may notice improvement with mirtazapine tablet therapy in 1 to 4 weeks, they should be advised to continue therapy as directed.

Concomitant Medication

Patients should be advised to inform their physician if they are taking, or intend to take, any prescription or over-the-counter drugs, since there is a potential for mirtazapine tablets to interact with other drugs. Patients should be made aware of a potential increased risk for serotonin syndrome if concomitant use of mirtazapine tablets with other serotonergic drugs, including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, buspirone, tryptophan, and St. John's wort, is clinically warranted, particularly during treatment initiation and dose increases.

Alcohol

The impairment of cognitive and motor skills produced by mirtazapine tablets has been shown to be additive with those produced by alcohol. Accordingly, patients should be advised to avoid alcohol while taking mirtazapine.

Pregnancy

Patients should be advised to notify their physician if they become pregnant or intend to become pregnant during mirtazapine tablets therapy.

Nursing

Patients should be advised to notify their physician if they are breastfeeding an infant.

Laboratory Tests

There are no routine laboratory tests recommended.

Drug

Interactions As with other drugs, the potential for interaction by a variety of mechanisms (e.g., pharmacodynamic, pharmacokinetic inhibition or enhancement, etc.) is a possibility (see CLINICAL PHARMACOLOGY).

Monoamine Oxidase

Inhibitors (See CONTRAINDICATIONS , WARNINGS , and DOSAGE AND ADMINISTRATION .)

Serotonergic

Drugs (See CONTRAINDICATIONS and WARNINGS .)

Drugs Affecting Hepatic Metabolism

The metabolism and pharmacokinetics of mirtazapine tablets may be affected by the induction or inhibition of drug-metabolizing enzymes. Drugs that are Metabolized by and/or Inhibit Cytochrome P450 Enzymes CYP Enzyme Inducers (these studies used both drugs at steady state) Phenytoin : In healthy male patients (n=18), phenytoin (200 mg daily) increased mirtazapine (30 mg daily) clearance about 2-fold, resulting in a decrease in average plasma mirtazapine concentrations of 45%. Mirtazapine did not significantly affect the pharmacokinetics of phenytoin. Carbamazepine : In healthy male patients (n=24), carbamazepine (400 mg b.i.d.) increased mirtazapine (15 mg b.i.d.) clearance about 2-fold, resulting in a decrease in average plasma mirtazapine concentrations of 60%. When phenytoin, carbamazepine, or another inducer of hepatic metabolism (such as rifampicin) is added to mirtazapine therapy, the mirtazapine dose may have to be increased. If treatment with such a medicinal product is discontinued, it may be necessary to reduce the mirtazapine dose.

Cyp

Enzyme Inhibitors Cimetidine : In healthy male patients (n=12), when cimetidine, a weak inhibitor of CYP1A2, CYP2D6, and CYP3A4, given at 800 mg b.i.d. at steady state was coadministered with mirtazapine (30 mg daily) at steady state, the Area Under the Curve (AUC) of mirtazapine increased more than 50%. Mirtazapine did not cause relevant changes in the pharmacokinetics of cimetidine. The mirtazapine dose may have to be decreased when concomitant treatment with cimetidine is started, or increased when cimetidine treatment is discontinued. Ketoconazole: In healthy, male, Caucasian patients (n=24), coadministration of the potent CYP3A4 inhibitor ketoconazole (200 mg b.i.d. for 6.5 days) increased the peak plasma levels and the AUC of a single 30-mg dose of mirtazapine by approximately 40% and 50%, respectively. Caution should be exercised when coadministering mirtazapine with potent CYP3A4 inhibitors, HIV protease inhibitors, azole antifungals, erythromycin, or nefazodone. Paroxetine : In an in vivo interaction study in healthy, CYP2D6 extensive metabolizer patients (n=24), mirtazapine (30 mg/day), at steady state, did not cause relevant changes in the pharmacokinetics of steady state paroxetine (40 mg/day), a CYP2D6 inhibitor.

Other

Drug-drug Interactions Amitriptyline In healthy, CYP2D6 extensive metabolizer patients (n=32), amitriptyline (75 mg daily), at steady state, did not cause relevant changes in the pharmacokinetics of steady state mirtazapine (30 mg daily); mirtazapine also did not cause relevant changes to the pharmacokinetics of amitriptyline. Warfarin In healthy male subjects (n=16), mirtazapine (30 mg daily), at steady state, caused a small (0.2) but statistically significant increase in the International Normalized Ratio (INR) in subjects treated with warfarin. As at a higher dose of mirtazapine, a more pronounced effect can not be excluded, it is advisable to monitor the INR in case of concomitant treatment of warfarin with mirtazapine. Lithium No relevant clinical effects or significant changes in pharmacokinetics have been observed in healthy male subjects on concurrent treatment with subtherapeutic levels of lithium (600 mg/day for 10 days) at steady state and a single 30-mg dose of mirtazapine. The effects of higher doses of lithium on the pharmacokinetics of mirtazapine are unknown. Risperidone In an in vivo , nonrandomized, interaction study, subjects (n=6) in need of treatment with an antipsychotic and antidepressant drug, showed that mirtazapine (30 mg daily) at steady state did not influence the pharmacokinetics of risperidone (up to 3 mg b.i.d.).

Alcohol

Concomitant administration of alcohol (equivalent to 60 g) had a minimal effect on plasma levels of mirtazapine (15 mg) in 6 healthy male subjects. However, the impairment of cognitive and motor skills produced by mirtazapine tablets were shown to be additive with those produced by alcohol. Accordingly, patients should be advised to avoid alcohol while taking mirtazapine tablets.

Diazepam

Concomitant administration of diazepam (15 mg) had a minimal effect on plasma levels of mirtazapine (15 mg) in 12 healthy subjects. However, the impairment of motor skills produced by mirtazapine tablets has been shown to be additive with those caused by diazepam. Accordingly, patients should be advised to avoid diazepam and other similar drugs while taking mirtazapine tablets. QTc-Prolonging Drugs The risk of QT prolongation and/or ventricular arrhythmias (e.g., Torsades de Pointes) may be increased with concomitant use of medicines which prolong the QTc interval (e.g., some antipsychotics and antibiotics) and in case of mirtazapine overdose (see ADVERSE REACTIONS and OVERDOSE sections). Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Carcinogenicity studies were conducted with mirtazapine given in the diet at doses of 2, 20, and 200 mg/kg/day to mice and 2, 20, and 60 mg/kg/day to rats. The highest doses used are approximately 20 and 12 times the maximum recommended human dose (MRHD) of 45 mg/day on an mg/m 2 basis in mice and rats, respectively. There was an increased incidence of hepatocellular adenoma and carcinoma in male mice at the high dose. In rats, there was an increase in hepatocellular adenoma in females at the mid and high doses and in hepatocellular tumors and thyroid follicular adenoma/cystadenoma and carcinoma in males at the high dose. The data suggest that the above effects could possibly be mediated by non-genotoxic mechanisms, the relevance of which to humans is not known. The doses used in the mouse study may not have been high enough to fully characterize the carcinogenic potential of mirtazapine tablets.

Mutagenesis

Mirtazapine was not mutagenic or clastogenic and did not induce general DNA damage as determined in several genotoxicity tests: Ames test, in vitro gene mutation assay in Chinese hamster V 79 cells, in vitro sister chromatid exchange assay in cultured rabbit lymphocytes, in vivo bone marrow micronucleus test in rats, and unscheduled DNA synthesis assay in HeLa cells. Impairment of Fertility In a fertility study in rats, mirtazapine was given at doses up to 100 mg/kg [20 times the maximum recommended human dose (MRHD) on an mg/m 2 basis]. Mating and conception were not affected by the drug, but estrous cycling was disrupted at doses that were 3 or more times the MRHD, and pre-implantation losses occurred at 20 times the MRHD.

Pregnancy Teratogenic

Effects - Pregnancy Category C Reproduction studies in pregnant rats and rabbits at doses up to 100 mg/kg and 40 mg/kg, respectively [20 and 17 times the maximum recommended human dose (MRHD) on an mg/m 2 basis, respectively], have revealed no evidence of teratogenic effects. However, in rats, there was an increase in postimplantation losses in dams treated with mirtazapine. There was an increase in pup deaths during the first 3 days of lactation and a decrease in pup birth weights. The cause of these deaths is not known. The effects occurred at doses that were 20 times the MRHD, but not at 3 times the MRHD, on an mg/m 2 basis. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Nursing Mothers

Because some mirtazapine may be excreted into breast milk, caution should be exercised when mirtazapine tablets are administered to nursing women.

Pediatric Use

Safety and effectiveness in the pediatric population have not been established (see BOXED WARNING and WARNINGS: Clinical Worsening and Suicide Risk ). Two placebo-controlled trials in 258 pediatric patients with MDD have been conducted with mirtazapine tablets, and the data were not sufficient to support a claim for use in pediatric patients. Anyone considering the use of mirtazapine tablets in a child or adolescent must balance the potential risks with the clinical need. In an 8-week-long pediatric clinical trial of doses between 15 to 45 mg/day, 49% of mirtazapine-treated patients had a weight gain of at least 7%, compared to 5.7% of placebo-treated patients. The mean increase in weight was 4 kg (2 kg SD) for mirtazapine-treated patients versus 1 kg (2 kg SD) for placebo-treated patients (see PRECAUTIONS, Increased Appetite/Weight Gain ).

Geriatric Use Approximately

190 elderly individuals (≥65 years of age) participated in clinical studies with mirtazapine tablets. This drug is known to be substantially excreted by the kidney (75%), and the risk of decreased clearance of this drug is greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection. Sedating drugs may cause confusion and over-sedation in the elderly. No unusual adverse age-related phenomena were identified in this group. Pharmacokinetic studies revealed a decreased clearance in the elderly. Caution is indicated in administering mirtazapine tablets to elderly patients (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION ).

Information for Patients Prescribers or other health professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with mirtazapine tablets and should counsel them in its appropriate use. A patient Medication Guide about “Antidepressant Medicines, Depression and other Serious Mental Illnesses, and Suicidal Thoughts or Actions” is available for mirtazapine tablets. The prescriber or health professional should instruct patients, their families, and their caregivers to read the Medication Guide and should assist them in understanding its contents. Patients should be given the opportunity to discuss the contents of the Medication Guide and to obtain answers to any questions they may have. The complete text of the Medication Guide is reprinted at the end of this document. Patients should be advised of the following issues and asked to alert their prescriber if these occur while taking mirtazapine tablets.

Clinical

Worsening and Suicide Risk Patients, their families, and their caregivers should be encouraged to be alert to the emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, mania, other unusual changes in behavior, worsening of depression, and suicidal ideation, especially early during antidepressant treatment and when the dose is adjusted up or down. Families and caregivers of patients should be advised to look for the emergence of such symptoms on a day-to-day basis, since changes may be abrupt. Such symptoms should be reported to the patient's prescriber or health professional, especially if they are severe, abrupt in onset, or were not part of the patient's presenting symptoms. Symptoms such as these may be associated with an increased risk for suicidal thinking and behavior and indicate a need for very close monitoring and possibly changes in the medication.

Agranulocytosis

Patients who are to receive mirtazapine tablets should be warned about the risk of developing agranulocytosis. Patients should be advised to contact their physician if they experience any indication of infection such as fever, chills, sore throat, mucous membrane ulceration, or other possible signs of infection. Particular attention should be paid to any flu-like complaints or other symptoms that might suggest infection. Interference with Cognitive and Motor Performance Mirtazapine tablets may impair judgment, thinking, and particularly, motor skills, because of its prominent sedative effect. The drowsiness associated with mirtazapine use may impair a patient’s ability to drive, use machines, or perform tasks that require alertness. Thus, patients should be cautioned about engaging in hazardous activities until they are reasonably certain that mirtazapine tablet therapy does not adversely affect their ability to engage in such activities.

Completing

Course of Therapy While patients may notice improvement with mirtazapine tablet therapy in 1 to 4 weeks, they should be advised to continue therapy as directed.

Concomitant Medication

Patients should be advised to inform their physician if they are taking, or intend to take, any prescription or over-the-counter drugs, since there is a potential for mirtazapine tablets to interact with other drugs. Patients should be made aware of a potential increased risk for serotonin syndrome if concomitant use of mirtazapine tablets with other serotonergic drugs, including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, buspirone, tryptophan, and St. John's wort, is clinically warranted, particularly during treatment initiation and dose increases.

Alcohol

The impairment of cognitive and motor skills produced by mirtazapine tablets has been shown to be additive with those produced by alcohol. Accordingly, patients should be advised to avoid alcohol while taking mirtazapine.

Pregnancy

Patients should be advised to notify their physician if they become pregnant or intend to become pregnant during mirtazapine tablets therapy.

Nursing

Patients should be advised to notify their physician if they are breastfeeding an infant.

Laboratory Tests

There are no routine laboratory tests recommended.

Drug

Interactions As with other drugs, the potential for interaction by a variety of mechanisms (e.g., pharmacodynamic, pharmacokinetic inhibition or enhancement, etc.) is a possibility (see CLINICAL PHARMACOLOGY).

Monoamine Oxidase

Inhibitors (See CONTRAINDICATIONS , WARNINGS , and DOSAGE AND ADMINISTRATION .)

Serotonergic

Drugs (See CONTRAINDICATIONS and WARNINGS .)

Drugs Affecting Hepatic Metabolism

The metabolism and pharmacokinetics of mirtazapine tablets may be affected by the induction or inhibition of drug-metabolizing enzymes. Drugs that are Metabolized by and/or Inhibit Cytochrome P450 Enzymes CYP Enzyme Inducers (these studies used both drugs at steady state) Phenytoin : In healthy male patients (n=18), phenytoin (200 mg daily) increased mirtazapine (30 mg daily) clearance about 2-fold, resulting in a decrease in average plasma mirtazapine concentrations of 45%. Mirtazapine did not significantly affect the pharmacokinetics of phenytoin. Carbamazepine : In healthy male patients (n=24), carbamazepine (400 mg b.i.d.) increased mirtazapine (15 mg b.i.d.) clearance about 2-fold, resulting in a decrease in average plasma mirtazapine concentrations of 60%. When phenytoin, carbamazepine, or another inducer of hepatic metabolism (such as rifampicin) is added to mirtazapine therapy, the mirtazapine dose may have to be increased. If treatment with such a medicinal product is discontinued, it may be necessary to reduce the mirtazapine dose.

Cyp

Enzyme Inhibitors Cimetidine : In healthy male patients (n=12), when cimetidine, a weak inhibitor of CYP1A2, CYP2D6, and CYP3A4, given at 800 mg b.i.d. at steady state was coadministered with mirtazapine (30 mg daily) at steady state, the Area Under the Curve (AUC) of mirtazapine increased more than 50%. Mirtazapine did not cause relevant changes in the pharmacokinetics of cimetidine. The mirtazapine dose may have to be decreased when concomitant treatment with cimetidine is started, or increased when cimetidine treatment is discontinued. Ketoconazole: In healthy, male, Caucasian patients (n=24), coadministration of the potent CYP3A4 inhibitor ketoconazole (200 mg b.i.d. for 6.5 days) increased the peak plasma levels and the AUC of a single 30-mg dose of mirtazapine by approximately 40% and 50%, respectively. Caution should be exercised when coadministering mirtazapine with potent CYP3A4 inhibitors, HIV protease inhibitors, azole antifungals, erythromycin, or nefazodone. Paroxetine : In an in vivo interaction study in healthy, CYP2D6 extensive metabolizer patients (n=24), mirtazapine (30 mg/day), at steady state, did not cause relevant changes in the pharmacokinetics of steady state paroxetine (40 mg/day), a CYP2D6 inhibitor.

Other

Drug-drug Interactions Amitriptyline In healthy, CYP2D6 extensive metabolizer patients (n=32), amitriptyline (75 mg daily), at steady state, did not cause relevant changes in the pharmacokinetics of steady state mirtazapine (30 mg daily); mirtazapine also did not cause relevant changes to the pharmacokinetics of amitriptyline. Warfarin In healthy male subjects (n=16), mirtazapine (30 mg daily), at steady state, caused a small (0.2) but statistically significant increase in the International Normalized Ratio (INR) in subjects treated with warfarin. As at a higher dose of mirtazapine, a more pronounced effect can not be excluded, it is advisable to monitor the INR in case of concomitant treatment of warfarin with mirtazapine. Lithium No relevant clinical effects or significant changes in pharmacokinetics have been observed in healthy male subjects on concurrent treatment with subtherapeutic levels of lithium (600 mg/day for 10 days) at steady state and a single 30-mg dose of mirtazapine. The effects of higher doses of lithium on the pharmacokinetics of mirtazapine are unknown. Risperidone In an in vivo , nonrandomized, interaction study, subjects (n=6) in need of treatment with an antipsychotic and antidepressant drug, showed that mirtazapine (30 mg daily) at steady state did not influence the pharmacokinetics of risperidone (up to 3 mg b.i.d.).

Alcohol

Concomitant administration of alcohol (equivalent to 60 g) had a minimal effect on plasma levels of mirtazapine (15 mg) in 6 healthy male subjects. However, the impairment of cognitive and motor skills produced by mirtazapine tablets were shown to be additive with those produced by alcohol. Accordingly, patients should be advised to avoid alcohol while taking mirtazapine tablets.

Diazepam

Concomitant administration of diazepam (15 mg) had a minimal effect on plasma levels of mirtazapine (15 mg) in 12 healthy subjects. However, the impairment of motor skills produced by mirtazapine tablets has been shown to be additive with those caused by diazepam. Accordingly, patients should be advised to avoid diazepam and other similar drugs while taking mirtazapine tablets. QTc-Prolonging Drugs The risk of QT prolongation and/or ventricular arrhythmias (e.g., Torsades de Pointes) may be increased with concomitant use of medicines which prolong the QTc interval (e.g., some antipsychotics and antibiotics) and in case of mirtazapine overdose (see ADVERSE REACTIONS and OVERDOSE sections).