Acitretine

Acitretin (Soriatane(R)) is an aromatic retinoïd (carboxylic acid metabolite of etretinate). Acitretin has a terminal elimination half-life of about 55 to 60 hours. However, concomitant intake of alcohol induces transformation to etretinate (lipophilic ester) which has a longer terminal elimination half life (84 to 168 days). Due to the teratogenic effect of acitretin, contraception should be used during therapy and 2 years afterwards. Acitretin monotherapy is effective in pustular psoriasis and psoriatic palmo-plantar keratoderma. In the other forms of psoriasis, combination with phototherapy (PUVA, UVB) or topical therapy is necessary (calcipotriol, corticosteroids). Acitretin is effective in cutaneous disorders of keratinization (ichtyosis, palmo-plantar keratoderma, Darier's disease). Severe cutaneous forms of lichen planus were recently recognized as indications of acitretin treatment; 35 to 40 mg daily is the mean effective dosage in adults (0.5 mg/kg/j in children). Acitretin was shown effective in preventing the development of new skin carcinomas in predisposed patients (Xeroderma pigmentosum, immunosupression). Acitretin is a potent teratogen. Mucocutaneous side effects are varied (cheilitis, dry mucosae, xerosis, palmo-plantar peeling, hair loss.), dose-dependent and reversible. Biological side-effects consist principally in elevations of transaminases (5 to 8% of patients). Acute hepatotoxic reactions are rare. Hyperlipidemia is another side-effect commonly observed. Bony changes (ligament calcifications, osteoporosis) have been reported with various incidence. In children, growth and development have to be monitored. Combination of acitretin with potentially hepatotoxic molecules (methotrexate) is contraindicated, as is combination with cyclines (risk of intracranial hypertension).