Overview
DESCRIPTION Acitretin, USP, a retinoid, is available in 10-mg, 17.5-mg, and 25-mg gelatin capsules for oral administration. Chemically, acitretin is all-trans-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-nonatetraenoic acid. It is a metabolite of etretinate and is related to both retinoic acid and retinol (vitamin A).
Mechanism of Action
CLINICAL PHARMACOLOGY The mechanism of action of acitretin is unknown. Pharmacokinetics: Absorption: Oral absorption of acitretin is optimal when given with food. For this reason, acitretin was given with food in all of the following trials. After administration of a single 50-mg oral dose of acitretin to 18 healthy subjects, maximum plasma concentrations ranged from 196 to 728 ng per mL (mean: 416 ng per mL) and were achieved in 2 to 5 hours (mean: 2.7 hours). The oral absorption of acitretin is linear and proportional with increasing doses from 25 to 100 mg. Approximately 72% (range: 47% to 109%) of the administered dose was absorbed after a single 50-mg dose of acitretin was given to 12 healthy subjects. Distribution: Acitretin is more than 99.
Indications
- INDICATIONS AND USAGE Acitretin Capsules, USP are indicated for the treatment of severe psoriasis in adults. Because of significant adverse effects associated with its use, Acitretin Capsules, USP should be prescribed only by those knowledgeable in the systemic use of retinoids. In females of reproductive potential, Acitretin Capsules, USP 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, USP can cause severe birth defects).
Common Doses
- 50 mg
Dosage
DOSAGE AND ADMINISTRATION There is intersubject variation in the pharmacokinetics, clinical efficacy, and incidence of side effects with Acitretin Capsules, USP. 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, USP 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.
Black Box 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.
Contraindications
- CONTRAINDICATIONS Pregnancy Category X: ( 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 , WARNINGS: 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 ).
Side Effects
- 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. Adverse Events/Postmarketing Reports: In addition to the events listed in the tables for the clinical trials, the following adverse events have been identified during postapproval use of acitretin.
Interactions
- Pharmacokinetic Drug Interactions (see also boxed CONTRAINDICATIONS AND WARNINGS and PRECAUTIONS : Drug Interactions ): In studies of in vivo pharmacokinetic drug interactions, no interaction was seen between acitretin and cimetidine, digoxin, phenprocoumon, or glyburide. Ethanol: Clinical evidence has shown that etretinate (a retinoid with a much longer half-life, see below) can be formed with concurrent ingestion of acitretin and ethanol.