Acitretin is indicated for the treatment of severe and extensive psoriasis that does not respond to other therapies. It is also used in palmo-plantar pustular psoriasis, severe congenital ichthyosis, and severe Darier’s disease (keratosis follicularis).

Acitretin is a retinoid and a synthetic derivative of vitamin A. Although its exact mechanism of action is not fully understood, it is known to act at multiple cellular and molecular levels. It influences gene expression by regulating RNA and DNA synthesis, controls abnormal skin cell proliferation, modifies glycoprotein production, and modulates immune responses. Its primary effect is the normalization of epidermal cell differentiation, restoring a more regular pattern of skin growth.

Adult and elderly: 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. In general, a daily dosage of 25-50 mg taken for a further 6 to 8 weeks to achieve optimal therapeutic results. However, it may be necessary in some cases to increase the dose up to a maximum of 75 mg/day.

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 50mg/day, should be given. Continuous use beyond 6 months is contra-indicated as only limited clinical data are available on patients treated beyond this length of time.

Children: The daily dosage is about 0.5mg/kg. Higher doses (up to 1mg/kg daily) may be necessary in some cases for limited periods, but only up to a maximum of 35 mg/day.

Concurrent use of acitretin with alcohol may lead to the formation of etretinate, which has a prolonged effect in the body. Co-administration with methotrexate, tetracyclines, vitamin A, or other retinoids is contraindicated due to increased toxicity risk. Acitretin may reduce protein binding of phenytoin, potentially altering its effect. Progesterone-only contraceptives (minipills) may be less effective during acitretin therapy. No significant interaction has been observed with coumarin-type anticoagulants such as warfarin.

Acitretin is highly teratogenic and must not be used during pregnancy. It is also contraindicated in women of childbearing potential unless strict contraception is maintained before, during, and after treatment (up to 2 years). It should not be used during breastfeeding. It is contraindicated in patients with severe liver or kidney impairment, chronic high lipid levels, hypersensitivity to retinoids, or rare glucose-galactose malabsorption. Concomitant use with vitamin A or other retinoids is also contraindicated.

Most patients experience some side effects with acitretin, especially during the early phase of treatment. These effects are usually dose-related and manageable. The most common effects involve the skin and mucous membranes, such as dryness. Temporary worsening of psoriasis symptoms may occur at the beginning of therapy.

Acitretin is strictly contraindicated during pregnancy and breastfeeding due to its high risk of causing birth defects. It should not be used in women who may become pregnant during treatment or within 2 years after stopping therapy.

There is a very high risk of severe birth defects if acitretin is used before or during pregnancy. Blood donation is prohibited during treatment and for 2 years afterward. Exposure to sunlight should be minimized as retinoids increase sensitivity to UV light. Liver function, lipid levels, and blood glucose should be regularly monitored. Patients should be informed about possible hair loss and decreased night vision. If severe symptoms like headache, nausea, vomiting, or visual disturbances occur, treatment should be stopped immediately.

Overdose may produce symptoms similar to vitamin A toxicity, including severe headache, dizziness, nausea, vomiting, drowsiness, irritability, and itching. Specific treatment is usually not required due to relatively low acute toxicity.

Oral Retinoid preparations

Store in a cool and dry place, protected from light. Do not store above 25°C.