ISOTRETINOIN Drug Interactions: What You Need to Know

Drug Interactions Vitamin A: Because of the relationship of isotretinoin to vitamin A, patients should be advised against taking vitamin supplements containing vitamin A to avoid additive toxic effects. Tetracyclines: Concomitant treatment with isotretinoin and tetracyclines should be avoided because isotretinoin use has been associated with a number of cases of pseudotumor cerebri (benign intracranial hypertension), some of which involved concomitant use of tetracyclines. Micro-dosed Progesterone Preparations: Micro-dosed progesterone preparations (“minipills” that do not contain an estrogen) may be an inadequate method of contraception during isotretinoin therapy. Although other hormonal contraceptives are highly effective, there have been reports of pregnancy from patients who can become pregnant who have used combined oral contraceptives, as well as transdermal patch/injectable/implantable/vaginal ring hormonal birth control products. These reports are more frequent for patients who can become pregnant who use only a single form of contraception. It is not known if hormonal contraceptives differ in their effectiveness when used with isotretinoin. Therefore, it is critically important for patients who can become pregnant to select and commit to use two forms of effective contraception simultaneously, at least one of which must be a primary form (see PRECAUTIONS ). Norethindrone/ethinyl estradiol: In a study of 31 premenopausal female patients with severe recalcitrant nodular acne receiving Ortho-Novum ® 7/7/7 Tablets as an oral contraceptive agent, isotretinoin at the recommended dose of 1 mg/kg/day, did not induce clinically relevant changes in the pharmacokinetics of ethinyl estradiol and norethindrone and in the serum levels of progesterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Prescribers are advised to consult the package insert of medication administered concomitantly with hormonal contraceptives, since some medications may decrease the effectiveness of these birth control products. St. John’s Wort: Isotretinoin use is associated with depression in some patients (see WARNINGS, Psychiatric Disorders and ADVERSE REACTIONS, Psychiatric ). Patients should be prospectively cautioned not to self-medicate with the herbal supplement St. John’s Wort because a possible interaction has been suggested with hormonal contraceptives based on reports of breakthrough bleeding on oral contraceptives shortly after starting St. John’s Wort. Pregnancies have been reported by users of combined hormonal contraceptives who also used some form of St. John’s Wort. Phenytoin: Isotretinoin has not been shown to alter the pharmacokinetics of phenytoin in a study in seven healthy volunteers. These results are consistent with the in vitro finding that neither isotretinoin nor its metabolites induce or inhibit the activity of the CYP 2C9 human hepatic P450 enzyme. Phenytoin is known to cause osteomalacia. No formal clinical studies have been conducted to assess if there is an interactive effect on bone loss between phenytoin and isotretinoin. Therefore, caution should be exercised when using these drugs together.

Systemic

Corticosteroids: Systemic corticosteroids are known to cause osteoporosis. No formal clinical studies have been conducted to assess if there is an interactive effect on bone loss between systemic corticosteroids and isotretinoin. Therefore, caution should be exercised when using these drugs together.

Laboratory Tests Pregnancy

Test - Patients who can become pregnant must have had two negative urine or serum pregnancy tests with a sensitivity of at least 25 mIU/mL before receiving the initial isotretinoin prescription. The first test (a screening test) is obtained by the prescriber when the decision is made to pursue qualification of the patient for isotretinoin. The second pregnancy test (a confirmation test) must be done in a CLIA-certified laboratory. The interval between the two tests must be at least 19 days. - For patients with regular menstrual cycles, the second pregnancy test must be done during the first 5 days of the menstrual period immediately preceding the beginning of isotretinoin therapy and after the patient has used 2 forms of contraception for 1 month. - For patients with amenorrhea, irregular cycles, or using a contraceptive method that precludes withdrawal bleeding, the second pregnancy test must be done immediately preceding the beginning of isotretinoin therapy and after the patient has used 2 forms of contraception for 1 month. - Each month of therapy, patients must have a negative result from a urine or serum pregnancy test. A pregnancy test must be repeated each month, in a CLIA-certified laboratory, prior to the patient who can become pregnant receiving each prescription.

Lipids

Pretreatment and follow-up blood lipids should be obtained under fasting conditions. After consumption of alcohol, at least 36 hours should elapse before these determinations are made. It is recommended that these tests be performed at weekly or biweekly intervals until the lipid response to isotretinoin is established. The incidence of hypertriglyceridemia is one patient in four on isotretinoin therapy (see WARNINGS, Lipids ).

Liver Function Tests

Since elevations of liver enzymes have been observed during clinical trials, and hepatitis has been reported, pretreatment and follow-up liver function tests should be performed at weekly or biweekly intervals until the response to isotretinoin has been established (see WARNINGS, Hepatotoxicity ).

Glucose

Some patients receiving isotretinoin have experienced problems in the control of their blood sugar. In addition, new cases of diabetes have been diagnosed during isotretinoin therapy, although no causal relationship has been established.

Cpk

Some patients undergoing vigorous physical activity while on isotretinoin therapy have experienced elevated CPK levels; however, the clinical significance is unknown. There have been rare postmarketing reports of rhabdomyolysis, some associated with strenuous physical activity. In a clinical trial of 217 pediatric patients (12 to 17 years) with severe recalcitrant nodular acne, transient elevations in CPK were observed in 12% of patients, including those undergoing strenuous physical activity in association with reported musculoskeletal adverse events such as back pain, arthralgia, limb injury, or muscle sprain. In these patients, approximately half of the CPK elevations returned to normal within 2 weeks and half returned to normal within 4 weeks. No cases of rhabdomyolysis were reported in this trial.

Pregnancy ( 4.1 , 8.1 ) Hypersensitivity to this product or any of its components ( 4.2 , 5.15 )

4.1 Pregnancy Isotretinoin capsules are contraindicated in pregnancy <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ]</span> .

4.2 Hypersensitivity Isotretinoin capsules are contraindicated in patients with hypersensitivity to isotretinoin (or Vitamin A, given the chemical similarity to isotretinoin) or to any of its components (anaphylaxis and other allergic reactions have occurred) <span class="opacity-50 text-xs">[see Warnings and Precautions (5.14) ]</span> .

AND PRECAUTIONS

• Psychiatric Disorders (depression, psychosis, suicidal thoughts and behavior, and aggressive and/or violent behaviors): Prior to and during therapy assess for these conditions; stop if these conditions occur on therapy (5.4)
• Intracranial Hypertension (Pseudotumor Cerebri) : Avoid use with concomitant tetracyclines (5.5)
• Serious Skin Reactions : Monitor for Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious skin reactions (5.6)
• Acute Pancreatitis : If occurs, discontinue treatment (5.7)
• Lipid Abnormalities (hypertriglyceridemia, low HDL, and elevation of cholesterol): Monitor lipid levels at regular intervals; stop if hypertriglyceridemia cannot be controlled (5.8)
• Hearing Impairment : Discontinue and refer to specialized care (5.9)
• Hepatotoxicity : Monitor liver function tests prior to and during therapy (5.10 , 5.15)
• Inflammatory Bowel Disease : Discontinue for abdominal pain, rectal bleeding, or severe diarrhea (5.11)
• Musculoskeletal Abnormalities : Arthralgias, back pain, decreases in bone mineral density and premature epiphyseal closure (5.12)
• Ocular Abnormalities e.g., corneal opacities, decreased night vision: If visual symptoms occur, discontinue and refer for an ophthalmological exam (5.13)

5.1 Embryo-Fetal Toxicity ABSORICA/ABSORICA LD is contraindicated in pregnancy <span class="opacity-50 text-xs">[see Contraindications (4.1) ]</span> . Based on human data, ABSORICA/ABSORICA LD can cause fetal harm when administered to a pregnant patient. There is an extremely high risk that life-threatening birth defects will result if pregnancy occurs while taking any amount of ABSORICA/ABSORICA LD even for short periods of time. Potentially any fetus exposed during pregnancy can be affected. There are no accurate means of determining prenatally whether an exposed fetus has been affected. Major congenital malformations, spontaneous abortions, and premature births have been documented following exposure to isotretinoin during pregnancy <span class="opacity-50 text-xs">[see Use in Specific Populations (8.1) ]</span> . If a pregnancy occurs during ABSORICA/ABSORICA LD treatment, discontinue ABSORICA/ABSORICA LD immediately and refer the patient to an obstetrician/gynecologist experienced in reproductive toxicity for further evaluation and counseling. Any suspected fetal exposure during or 1 month after ABSORICA/ABSORICA LD therapy must be reported immediately to the FDA via the MedWatch telephone number 1-800-FDA-1088, and also to the iPLEDGE pregnancy registry at 1-866-495-0654 or via the internet (www.ipledgeprogram.com). Patients must be informed not to donate blood during ABSORICA/ABSORICA LD therapy and for 1 month following discontinuation because the blood might be given to a pregnant patient whose fetus must not be exposed to isotretinoin. ABSORICA/ABSORICA LD is available only through a restricted program under a REMS <span class="opacity-50 text-xs">[see Warnings and Precautions (5.2) ]</span>. 5.2 iPLEDGE Program ABSORICA/ABSORICA LD are available only through a restricted program under a REMS called the iPLEDGE REMS because of the risk of embryo-fetal toxicity <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1) ]</span> . Notable requirements of the iPLEDGE REMS include the following:

• Prescribers must be certified with the program and comply with the following requirements: Determine reproductive status of all patients prior to initiating treatment o Provide contraception counseling to patients who can get pregnant prior to and during treatment, or refer patients who can get pregnant to an expert for such counseling o Provide scheduled pregnancy testing, and verify and document the negative pregnancy test result prior to writing each prescription, for no more than a 30-day supply
• Patients who can become pregnant must be enrolled by signing an informed consent form and must comply with the following requirements o Comply with the pregnancy testing and contraception requirements [see Use in Specific Populations (8.3)] o Demonstrate comprehension of the safe-use conditions of the program every month o Obtain the prescription within 7 days of the pregnancy test collection
• Patients who cannot become pregnant must be enrolled by signing an informed consent form and must obtain the prescription within 30 days of the office visit
• Pharmacies that dispense ABSORICA/ABSORICA LD must be certified by being registered and activated in the program, must only dispense to patients who are authorized to receive ABSORICA/ABSORICA LD, and comply with the following requirements: o Only dispense a maximum of a 30-day supply with a Medication Guide. o Do not dispense refills. Dispense only with a new prescription and a new authorization from the program. o Return ABSORICA/ABSORICA LD to inventory if patients do not obtain the prescription by the “Do Not Dispense To After” date
• Wholesalers and distributors must be registered with the program and must only distribute to certified pharmacies. Further information, including a list of qualified pharmacies and distributors, is available at www.ipledgeprogram.com or 1-866-495-0654.

5.3 ABSORICA and ABSORICA LD are Not Substitutable Given that the bioavailability and the recommended dosage of ABSORICA and ABSORICA LD are different, ABSORICA and ABSORICA LD are not substitutable. For example, ABSORICA and ABSORICA LD have a 20 mg strength; however, these strengths have different bioavailability and are not substitutable.

5.4 Psychiatric Disorders ABSORICA/ABSORICA LD may cause depression, psychosis and, rarely, suicidal ideation, suicide attempts, suicide, and aggressive and/or violent behaviors <span class="opacity-50 text-xs">[see Adverse Reactions (6) ]</span> . Healthcare providers should be alert to the warning signs of psychiatric disorders to help ensure patients receive the help they need (Prescribers should read the brochure, Recognizing Psychiatric Disorders in Adolescents and Young Adults: A Guide for Prescribers of Isotretinoin ). Prior to initiation of ABSORICA/ABSORICA LD therapy, patients and family members should be asked about any history of psychiatric disorder, and at each visit during therapy patients should be assessed for symptoms of depression, mood disturbance, psychosis, or aggression to determine if further evaluation is necessary. Patients should immediately stop ABSORICA/ABSORICA LD and the patient (or caregiver) should promptly contact their prescriber if the patient develops depression, mood disturbance, psychosis, or aggression. Discontinuation of ABSORICA/ABSORICA LD may be insufficient; further evaluation may be necessary such as a referral to a mental healthcare professional.

5.5 Intracranial Hypertension (Pseudotumor Cerebri) Isotretinoin use has been associated with cases of intracranial hypertension (pseudotumor cerebri), some of which involved concomitant use of tetracyclines. Concomitant treatment with tetracyclines should therefore be avoided with ABSORICA/ABSORICA LD use. Early signs and symptoms of intracranial hypertension include papilledema, headache, nausea and vomiting, and visual disturbances. Patients with these symptoms should be screened for papilledema and, if present, they should be told to discontinue ABSORICA/ABSORICA LD immediately and be referred to a neurologist for further diagnosis and care <span class="opacity-50 text-xs">[see Adverse Reactions ( 6 )]</span> .

5.6 Serious Skin Reactions There have been postmarketing reports of erythema multiforme and severe skin reactions [e.g., Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN)] associated with isotretinoin use. These reactions may be serious and result in death, life-threatening events, hospitalization, or disability. Patients should be monitored closely for severe skin reactions, and ABSORICA/ABSORICA LD should be discontinued if they occur.

5.7 Pancreatitis Acute pancreatitis has been reported with isotretinoin use in patients with either elevated or normal serum triglyceride levels. In rare instances, fatal hemorrhagic pancreatitis has been reported. If symptoms of pancreatitis occur, discontinue ABSORICA/ABSORICA LD and seek medical attention.

5.8 Lipid Abnormalities Elevations of serum triglycerides above 800 mg/dL have been reported with isotretinoin use. In clinical trials, marked elevations of serum triglycerides, decreases in high-density lipoproteins (HDL), and increases in cholesterol levels were reported in 25%, 15%, and 7% of patients treated with isotretinoin capsules, respectively. These lipid changes were reversible upon isotretinoin capsule cessation. Some patients have been able to reverse triglyceride elevation by reduction in weight and restriction of dietary fat and alcohol while continuing isotretinoin or through dosage reduction. The cardiovascular consequences of hypertriglyceridemia associated with isotretinoin are unknown. Fasting lipid tests should be performed before ABSORICA/ABSORICA LD treatment and then at intervals until the lipid response to ABSORICA/ABSORICA LD is known, which usually occurs within 4 weeks. Careful consideration should be given to risk/benefit of ABSORICA/ABSORICA LD in patients who are at higher risk of hypertriglyceridemia (e.g., patients with diabetes, obesity, increased alcohol intake, lipid metabolism disorder or familial history of lipid metabolism disorder). If ABSORICA/ABSORICA LD therapy is instituted in such patients, more frequent checks of serum values for lipids are recommended <span class="opacity-50 text-xs">[see Warnings and Precautions (5.15) ]</span> . ABSORICA/ABSORICA LD should be stopped if hypertriglyceridemia cannot be controlled.

5.9 Hearing Impairment Impaired hearing has been reported in patients taking isotretinoin; in some cases, the hearing impairment has been reported to persist after therapy has been discontinued. Mechanism(s) and causality for this reaction have not been established. Patients who experience tinnitus or hearing impairment should discontinue ABSORICA/ABSORICA LD treatment and be referred for specialized care for further evaluation.

5.10 Hepatotoxicity Clinical hepatitis has been reported with isotretinoin use. Additionally, mild to moderate elevations of liver enzymes have been observed in approximately 15% of individuals treated during clinical trials with isotretinoin capsules, some of which normalized with dosage reduction or continued administration of the drug. If normalization does not readily occur or if hepatitis is suspected during treatment, ABSORICA/ABSORICA LD should be discontinued.

5.11 Inflammatory Bowel Disease Isotretinoin has been associated with inflammatory bowel disease (including regional ileitis) in patients without a prior history of intestinal disorders. In some instances, symptoms have been reported to persist after isotretinoin treatment has been stopped. Patients experiencing abdominal pain, rectal bleeding or severe diarrhea should discontinue ABSORICA/ABSORICA LD immediately <span class="opacity-50 text-xs">[see Adverse Reactions (6) ]</span> .

5.12 Musculoskeletal Abnormalities Bone Mineral Density Changes, Osteoporosis, and Fractures Isotretinoin may have a negative effect on bone mineral density (BMD) in some patients. In a clinical trial of ABSORICA and another isotretinoin capsule product, 27/306 (9%) of adolescents had BMD declines, defined as ≥ 4% lumbar spine or total hip, or ≥ 5% femoral neck, during the 20-week treatment period. Repeat scans conducted within 2 to 3 months after the post-treatment scan showed no recovery of BMD. Long-term data at 4 to 11 months showed that 3 out of 7 patients had total hip and femoral neck BMD below pre-treatment baseline, and 2 others did not show the increase in BMD above baseline expected in this adolescent population. Therefore, healthcare providers should use caution when prescribing ABSORICA/ABSORICA LD to patients with a history of childhood osteoporosis conditions, osteomalacia, or other disorders of bone metabolism. This would include patients diagnosed with anorexia nervosa and those who are on chronic drug therapy that causes drug-induced osteoporosis/osteomalacia and/or affects vitamin D metabolism, such as systemic corticosteroids and any anticonvulsant <span class="opacity-50 text-xs">[see Use in Specific Populations (8.4) ]</span> . There have been spontaneous reports of osteoporosis, osteopenia, fractures and/or delayed healing of fractures in patients while on therapy with isotretinoin or following cessation of therapy with isotretinoin. Patients in early and late adolescence who participate in sports with repetitive impact may be at an increased risk of spondylolisthesis with and without pars fractures, and hip growth plate injuries have been reported.

Musculoskeletal Abnormalities Approximately

16% of patients treated with isotretinoin capsules in a clinical trial developed musculoskeletal symptoms (including arthralgia) during treatment. In general, these symptoms were mild to moderate, but occasionally required discontinuation of isotretinoin. In a trial of pediatric patients treated with isotretinoin capsules, approximately 29% (104/358) developed back pain. Back pain was severe in 14% (14/104) of the cases and occurred at a higher frequency in female patients than male patients. Arthralgias were experienced in 22% (79/358) of pediatric patients. Arthralgias were severe in 8% (6/79) of patients. Appropriate evaluation of the musculoskeletal system should be done in patients who present with these symptoms during or after a course of ABSORICA/ABSORICA LD. Consider discontinuing ABSORICA/ABSORICA LD if any significant abnormality is found. Effects of multiple courses of isotretinoin on the developing musculoskeletal system are unknown. There is some evidence that long-term, high-dose, or multiple courses of therapy with isotretinoin have more of an effect than a single course of therapy on the musculoskeletal system. It is important that ABSORICA/ABSORICA LD be given at the recommended dose for no longer than the recommended duration. Hyperostosis A high prevalence of skeletal hyperostosis was noted in clinical trials for disorders of keratinization with a mean dose of 2.24 mg/kg/day of isotretinoin capsules (approximately 1.1 times the maximum recommended daily dosage). Additionally, skeletal hyperostosis was noted in 6 of 8 patients in a prospective trial of disorders of keratinization. Minimal skeletal hyperostosis and calcification of ligaments and tendons have also been observed by x-ray in prospective trials of nodular acne patients treated with a single course of therapy at recommended doses. The skeletal effects of multiple isotretinoin treatment courses for acne are unknown. In a clinical trial of 217 pediatric patients (12 to 17 years) with severe recalcitrant nodular acne, hyperostosis was not observed after 16 to 20 weeks of treatment with approximately 1 mg/kg/day of isotretinoin capsules given in two divided doses. Hyperostosis may require a longer time frame to appear. The clinical course and significance remain unknown.

Premature Epiphyseal Closure

There are spontaneous literature reports of premature epiphyseal closure in acne patients receiving recommended doses of isotretinoin capsules. The effect of multiple courses of isotretinoin on epiphyseal closure is unknown. In a 20-week clinical trial that included 289 adolescents on ABSORICA or another isotretinoin capsule product who had hand radiographs taken to assess bone age, a total of 9 (3%) patients had bone age changes that were clinically significant and for which a drug-related effect cannot be excluded.

5.13 Ocular Abnormalities Visual problems should be carefully monitored. If visual difficulties occur, discontinue ABSORICA/ABSORICA LD treatment and obtain an ophthalmological examination <span class="opacity-50 text-xs">[see Adverse Reactions (6) ]</span>.

Corneal Opacities

Corneal opacities have occurred in patients receiving isotretinoin capsules and more frequently when higher drug dosages were used in patients with disorders of keratinization. The corneal opacities that have been observed in clinical trial patients treated with isotretinoin capsules have either completely resolved or were resolving at follow-up 6 to 7 weeks after discontinuation of isotretinoin [see Adverse Reactions (6) ].

Decreased Night Vision

Decreased night vision has been reported during isotretinoin use and in some instances the event has persisted after therapy was discontinued. Because the onset in some patients was sudden, patients should be advised of this potential problem and warned to be cautious when driving or operating any vehicle at night.

Dry Eyes

Dry eyes has been reported in patients during isotretinoin use. Patients who wear contact lenses may have trouble wearing them while on ABSORICA/ABSORICA LD treatment and afterwards.

5.14 Hypersensitivity Reactions Anaphylactic reactions and other allergic reactions have been reported with isotretinoin use. Cutaneous allergic reactions and serious cases of allergic vasculitis, often with purpura (bruises and red patches) of the extremities and extracutaneous involvement (including renal) have been reported. Severe allergic reaction necessitates discontinuation of therapy and appropriate medical management.

Allergic Reactions

Due to the Inactive Ingredient (FD&C Yellow No. 5) in the 25 mg ABSORICA Capsule The 25 mg ABSORICA capsule contains FD&C Yellow No. 5 (tartrazine) which may cause allergic-type reactions (including bronchial asthma) in certain susceptible persons. Although the overall incidence of tartrazine sensitivity in the general population is low, it is frequently seen in patients who also have aspirin hypersensitivity.

The

10 mg, 20 mg, 30 mg, 35 mg, and 40 mg ABSORICA capsules do not contain FD&C Yellow No. 5 and all of the ABSORICA LD capsules do not contain FD&C Yellow No. 5. Thus, in patients with allergic reactions to tartrazine, avoid using the 25 mg ABSORICA capsules.

5.15 Laboratory Abnormalities and Laboratory Monitoring for Adverse Reactions Laboratory Monitoring Pregnancy Testing A pregnancy test must be obtained prior to obtaining a prescription , repeated each month, at the end of the entire course of ABSORICA/ABSORICA LD therapy and 1 month after the discontinuation of ABSORICA/ABSORICA LD <span class="opacity-50 text-xs">[see Use in Specific Populations (8.3) ]</span>.

Lipid Tests

Pretreatment and follow-up fasting lipid tests should be obtained under fasting conditions. After consumption of alcohol, at least 36 hours should elapse before testing is performed. It is recommended that these tests be performed periodically until the lipid response to ABSORICA/ABSORICA LD is known. The incidence of hypertriglyceridemia is 25% in patients treated with isotretinoin capsules [see Warnings and Precautions (5.8) ] .

Liver Function

Tests As elevations of liver enzymes have been observed during clinical trials, and hepatitis has been reported in patients on isotretinoin capsules, pretreatment and follow-up liver function tests should be performed periodically until the response to ABSORICA/ABSORICA LD is known [see Warnings and Precautions (5.10) ].

Additional Laboratory Abnormalities Glucose

With isotretinoin use, some patients have experienced problems in the control of their blood sugar. In addition, new cases of diabetes have been diagnosed during isotretinoin use.

Cpk

Some patients undergoing vigorous physical activity while taking isotretinoin have experienced elevated CPK levels; however, the clinical significance is unknown. There have been rare postmarketing reports of rhabdomyolysis with isotretinoin use, some associated with strenuous physical activity. In a clinical trial of 924 patients, marked elevations in CPK (≥350 U/L) were observed in approximately 24% of patients treated with isotretinoin capsules. In another clinical trial of 217 pediatric patients (12 to 17 years old) elevations in CPK were observed in 12% of patients, including those undergoing strenuous physical activity in association with reported musculoskeletal adverse events such as back pain, arthralgia, limb injury, or muscle sprain. In these patients, approximately half of the CPK elevations returned to normal within 2 weeks and half returned to normal within 4 weeks. No cases of rhabdomyolysis were reported in this clinical trial.