Acitretin is a second-generation retinoid. It is taken orally, and is typically used for psoriasis. It is a metabolite of etretinate, which was used prior to the introduction of acitretin. Acitretin is an oral retinoid used in the treatment of severe resistant psoriasis. Because of the potential for problems and severe side effects it is generally used in only very severe cases of psoriasis that have been unresponsive to other treatments. It binds to nuclear receptors that regulates gene transcription. They induce keratinocyte differentiation and reduce epidermal hyperplasia, leading to the slowing of cell reproduction. Acitretin is readily absorbed and widely distributed after oral administration. A therapeutic effect occurs after 2 to 4 weeks or longer. Patients that have received the medication are advised against giving blood for at least 3 years due to the risk of birth defects.
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