Acitretin (2 brand names, 1 dosage form, 1 route)
Available dosage forms: CAPSULE.
Routes of administration: ORAL.
Brand Names
- ACITRETIN
- SORIATANE
Boxed Warning
CONTRAINDICATIONS AND WARNINGS: Pregnancy Acitretin must not be used by females who are pregnant, or who intend to become pregnant during therapy or at any time for at least 3 years following discontinuation of therapy. Acitretin also must not be used by females who may not use reliable contraception while undergoing treatment and for at least 3 years following discontinuation of treatment. Acitretin is a metabolite of etretinate (TEGISON), and major human fetal abnormalities have been reported with the administration of acitretin and etretinate. Potentially, any fetus exposed can be affected. Clinical evidence has shown that concurrent ingestion of acitretin and ethanol has been associated with the formation of etretinate, which has a significantly longer elimination half-life than acitretin. Because the longer elimination half-life of etretinate would increase the duration of teratogenic potential for female patients, ethanol must not be ingested by female patients of childbearing potential either during treatment with acitretin or for 2 months after cessation of therapy. This allows for elimination of acitretin, thus removing the substrate for transesterification to etretinate. The mechanism of the metabolic process for conversion of acitretin to etretinate has not been fully defined. It is not known whether substances other than ethanol are associated with transesterification. Acitretin has been shown to be embryotoxic and/or teratogenic in rabbits, mice, and rats at oral doses of 0.6, 3, and 15 mg per kg, respectively. These doses are approximately 0.2, 0.3, and 3 times the maximum recommended therapeutic dose, respectively, based on a mg-per-m2 comparison. Major human fetal abnormalities associated with acitretin and/or etretinate administration have been reported including meningomyelocele; meningoencephalocele; multiple synostoses; facial dysmorphia; syndactyly; absence of terminal phalanges; malformations of hip, ankle, and forearm; low-set ears; high palat
Indications and Usage
Acitretin Capsules are indicated for the treatment of severe psoriasis in adults. Because of significant adverse effects associated with its use, Acitretin Capsules should be prescribed only by those knowledgeable in the systemic use of retinoids. In females of reproductive potential, Acitretin Capsules should be reserved for non-pregnant patients who are unresponsive to other therapies or whose clinical condition contraindicates the use of other treatments (see boxed CONTRAINDICATIONS AND WARNINGS — Acitretin Capsules can cause severe birth defects). Most patients experience relapse of psoriasis after discontinuing therapy. Subsequent courses, when clinically indicated, have produced efficacy results similar to the initial course of therapy.
Dosage and Administration
There is intersubject variation in the pharmacokinetics, clinical efficacy, and incidence of side effects with acitretin capsules. A number of the more common side effects are dose-related. Individualization of dosage is required to achieve sufficient therapeutic response while minimizing side effects. Therapy with acitretin capsules should be initiated at 25 to 50 mg per day, given as a single dose with the main meal. Maintenance doses of 25 to 50 mg per day may be given dependent upon an individual patient’s response to initial treatment. Relapses may be treated as outlined for initial therapy. When acitretin capsules are used with phototherapy, the prescriber should decrease the phototherapy dose, dependent on the patient’s individual response (see PRECAUTIONS ). Females who have taken TEGISON (etretinate) must continue to follow the contraceptive recommendations for TEGISON. TEGISON is no longer marketed in the U.S.; for information, call 1-888-838-2872. Information for Pharmacists Acitretin capsules must only be dispensed in no more than a monthly supply. An acitretin capsules Medication Guide must be given to the patient each time acitretin capsules are dispensed, as required by law.
Contraindications
(See boxed CONTRAINDICATIONS AND WARNINGS.) Acitretin is contraindicated in patients with severely impaired liver or kidney function and in patients with chronic abnormally elevated blood lipid values (see boxed WARNINGS , Hepatotoxicity ; WARNIN GS , Lipids and Possible Cardiovascular Effects ; and PRECAUTIONS ). An increased risk of hepatitis has been reported to result from combined use of methotrexate and etretinate. Consequently, the combination of methotrexate with acitretin is also contraindicated (see PRECAUTIONS , Drug Interactions ). Since both acitretin and tetracyclines can cause increased intracranial pressure, their combined use is contraindicated (see WARNINGS, Pseudotumor Cerebri). Acitretin is contraindicated in cases of hypersensitivity (e.g., angioedema, urticaria) to the preparation (acitretin or excipients) or to other retinoids.
Adverse Reactions
Hypervitaminosis A produces a wide spectrum of signs and symptoms primarily of the mucocutaneous, musculoskeletal, hepatic, neuropsychiatric, and central nervous systems. Many of the clinical adverse reactions reported to date with administration of acitretin resemble those of the hypervitaminosis A syndrome.
Drug Interactions
Ethanol Clinical evidence has shown that etretinate can be formed with concurrent ingestion of acitretin and ethanol (see boxed CONTRAINDICATIONS AND WARNINGS and CLINICAL PHARMACOLOGY , Pharmacokinetics ). Glyburide In a trial of 7 healthy male volunteers, acitretin treatment potentiated the blood glucose-lowering effect of glyburide (a sulfonylurea similar to chlorpropamide) in 3 of the 7 subjects. Repeating the trial with 6 healthy male volunteers in the absence of glyburide did not detect an effect of acitretin on glucose tolerance. Careful supervision of diabetic patients under treatment with acitretin is recommended (see CLINICAL PHARMACOLOGY, Pharmacokinetics and DOSAGE AND ADMINISTRATION ). Hormonal Contraceptives It has not been established if there is a pharmacokinetic interaction between acitretin and combined oral contraceptives. However, it has been established that acitretin interferes with the contraceptive effect of microdosed progestin “minipill” preparations. Microdosed “minipill” progestin preparations are not recommended for use with acitretin (see CLINICAL PHARMACOLOGY , Pharmacokinetic Drug Interactions ). It is not known whether other progestin-only contraceptives, such as implants and injectables, are adequate methods of contraception during acitretin therapy. Methotrexate An increased risk of hepatitis has been reported to result from combined use of methotrexate and etretinate. Consequently, the combination of methotrexate with acitretin is also contraindicated (see CONTRAINDICATIONS ). Phenytoin If acitretin is given concurrently with phenytoin, the protein binding of phenytoin may be reduced. Tetracyclines Since both acitretin and tetracyclines can cause increased intracranial pressure, their combined use is contraindicated (see CONTRAINDICATIONS and WARNINGS , Pseudotumor Cerebri). Vitamin A and Oral Retinoids Concomitant administration of vitamin A and/or other oral retinoids with acitretin must be avoided because of the risk of hypervi
Overdosage
In the event of acute overdosage, acitretin must be withdrawn at once. Symptoms of overdose are identical to acute hypervitaminosis A (e.g., headache and vertigo). The acute oral toxicity (LD50) of acitretin in both mice and rats was greater than 4,000 mg per kg. In one reported case of overdose, a 32-year-old male with Darier’s disease took 21 x 25-mg capsules (525-mg single dose). He vomited several hours later but experienced no other ill effects. All female patients of childbearing potential who have taken an overdose of acitretin must: 1) Have a pregnancy test at the time of overdose; 2) Be counseled as per the boxed CONTRAINDICATIONS AND WARNINGS and PRECAUTIONS sections regarding birth defects and contraceptive use for at least 3 years’ duration after the overdose.