Acitretin is indicated for the treatment of severe psoriasis in adults. Because of significant adverse effects associated with its use, this should be prescribed only by those knowledgeable in the systemic use of retinoids. In females of reproductive potential, this should be reserved for non-pregnant patients who are unresponsive to other therapies or whose clinical condition contraindicates the use of other treatments 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.
Oral Retinoid preparations
Acitretin is a retinoid, an aromatic analogue of vitamin A. The mechanism of action of acitretin is unknown, however, evidence exists for a wide range of actions at various cellular and subcellular levels. These include regulation of RNA/DNA synthesis, modulation of factors which influence epidermal proliferation, modification of glycoprotein synthesis and modulation of the immune response. Whatever the exact mechanism of action, the most prominent effect of acitretin is a modulation of cellular differentiation in the epidermis which re-establishes a more normal pattern of cell growth.
It is recommended that Acitretin be given only by, or under supervision of, a dermatological specialist. Acitretin capsules are for oral administration. The capsules should be taken once daily with meals or with milk. There is a wide variation in the absorption and rate of metabolism of Acitretin. This necessitates individual adjustment of dosage. For this reason the following dosage recommendations can serve only as a guide. Adult: Initial daily dose should be 25 mg or 30 mg for 2 to 4 weeks. After this initial treatment period the involved areas of the skin should show a marked response and/or side-effects should be apparent. Following assessment of the initial treatment period, titration of the dose upwards or downwards may be necessary to achieve the desired therapeutic response with the minimum of side-effects. In general, a daily dosage of 25?50 mg taken for a further 6?8 weeks achieves optimal therapeutic results. However, it may be necessary in some cases to a maximum of 75 mg/day. Therapy can be discontinued in patients with psoriasis whose lesions have improved sufficiently. In patients with Darier$#$#$#$s disease a starting dose of 10 mg may be appropriate. The dose should be increased cautiously as isomorphic reactions may occur. Patients with severe congenital ichthyosis and severe Darier's disease may require therapy beyond 3 months. The lowest effective dosage, not exceeding 50 mg/day, should be given. Continuous use beyond 6 months is contraindicated as only limited clinical data are available on patients treated beyond this length of time. Children: Acitretin is contra-indicated in children unless the benefits significantly outweigh the risks, in view of possible severe side-effects associated with long-term treatment. The dosage should be established according to bodyweight. The daily dosage is about 0.5 mg/kg. Higher doses (up to 1 mg/kg daily) may be necessary in some cases for limited periods, but only up to a maximum of 35 mg/day. The maintenance dose should be kept as low as possible in view of possible long-term side-effects. Elderly: Dosage recommendations are the same as for other adults.
Existing data suggests that concurrent intake of acitretin with ethanol led to the formation of etretinate. Concomitant administration of methotrexate, tetracyclines or vitamin A and other retinoids with acitretin is contraindicated. In concurrent treatment with phenytoin, it must be remembered that Acitretin partially reduces the protein binding of phenytoin. Low dose progesterone-only products (minipills) may be an inadequate method of contraception during acitretin therapy, Investigations into the effect of acitretin on the protein binding of anticoagulants of the coumarin type (warfarin) revealed no interaction.
Acitretin is contra-indicated in cases of hypersensitivity to it or excipients or to other retinoids. Its use is contra-indicated in pregnant women and women who might become pregnant during or within 2 years of the cessation of treatment. It is also contra-indicated in patients with hepatic or renal impairment and in patients with chronic abnormally elevated blood lipid values. Acitretin should only be prescribed by physicians who are experienced in the use of systemic retinoids and understand the risk of teratogenicity associated with Acitretin therapy. The risk of giving birth to a deformed child is exceptionally high if Acitretin is taken before or during pregnancy, no matter for how long or at what dosage. Foetal exposure to Acitretin always involves a risk of congenital malformation. Donation of blood by a patient being treated with Acitretin is prohibited during and for two year after completion of treatment.
Most of the clinical side-effects of Acitretin are dose-related and are usually well-tolerated at the recommended dosages. However, the toxic dose of Acitretin is close to the therapeutic dose and most patients experience some side-effects during the initial period whilst dosage is being adjusted. They are usually reversible with reduction of dosage or discontinuation of therapy.
Acitretin is contra-indicated during pregnancy and in women who are breast feeding as it is a known human teratogen. It is also contra-indicated in women of childbearing potential unless specific criteria are met.
Manifestations of acute Vitamin A toxicity include severe headache, vertigo, nausea or vomiting, drowsiness, irritability and pruritus. Signs and symptoms of accidental or deliberate overdosage with Acitretin would probably be similar. Specific treatment is unnecessary because of the low acute toxicity of the preparation.
Store in a cool & dry place, protected from light. Do not store above 25°C.
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