Ацитретин

Описание

Acitretin is the free acid form of etretinate useful in the treatment of severe psoriasis and other disorders of keratinization. Although the two compounds have virtually the same efficacy and teratogenic side-effects, acitretin is advantageous for child-bearing women, as its shorter half-life reduces the necessary contraception period from two years to only one month after treatment ceases.

Химические свойства

Crystalline Solid

Использование

Acitretin, a retinoid that binds to nuclear receptors and regulates gene expression, is a potent activator of the α-secretase ADAM10 gene expression and apoptosis inducer via the CD95 signalling pathway. Acitretin is a systemic retinoid drug used in the treatment of severe psoriasis.

Показания

Unlike isotretinoin, acitretin (Soriatane) is not primarily sebosuppressive. Rather, it promotes normalization of dysregulated keratinocyte proliferative activity in the epidermis and is also antiinflammatory. Oral absorption is optimal when acitretin is taken with a fatty meal; peak levels are reached approximately 3 hours after ingestion, while steady-state plasma levels are achieved after approximately 3 weeks of daily dosing. The mean terminal elimination half-life of the parent compound is 49 hours. However, when consumed with ethanol, acitretin may be transesterified to form etretinate, a retinoid that is stored in adipose tissue, resulting in a much longer half-life (3–4 months or longer).

Всемирная организация здравоохранения(ВОЗ)

Acitretin, a retinol derivative, was introduced in 1989 for the treatment of severe psoriasis. By the end of 1990, acitretin was confirmed to be metabolized in part to etretinate. Marketing authorization was suspended temporarily in France while the product information was modified to conform to the recommendations issued by the Committee for Proprietary Medicinal Products of the European Communities. Acitretin remains registered in several countries. See also WHO comment for etretinate.

Общее описание

Pharmaceutical secondary standards for application in quality control, provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.
Acitretin is a major metabolite of etretinate and belongs to the class of retinoid and is typically used for treating psoriasis. Acitretin inhibits excessive cell growth and keratinisation which are the major symptoms of psoriasis, therefore reducing plaque formation and scaling.

Механизм действия

Acitretin (Soriatane) is a synthetic derivative of vitamin A that is particularly effective in treating the pustular and erythrodermic forms of psoriasis. It is the main metabolite of etretinate; ingestion of alcohol with acitretin increases the amount of detectable etretinate. It is accumulated in fatty tissue with a prolonged elimination half-life of approximately 120 days. Most patients show improvement within 2 to 4 weeks, although some patients may need as long as 6 months of therapy before a response is noted.

Фармаколо?гия

Like other systemic retinoids, acitretin is a serious teratogen and should not be prescribed for women of childbearing potential unless no acceptable alternative is available and the patient has acknowledged in writing that she understands the need to use two effective forms of contraception during therapy and for 3 years following discontinuation of therapy. Because of the much longer half-life of etretinate, which may be formed when ethanol is ingested with acitretin, female patients of childbearing potential must also agree not to ingest alcohol during treatment and for 2 months following its discontinuation. Other toxicities are similar to those of isotretinoin; they include cutaneous irritation and inflammation, bone and joint pain, hyperlipidemia, hepatic enzyme elevation, and tendinous and ligamentous calcifications.Alopecia (hair loss) may also occur in some patients.

Клиническое использование

Acitretin is most useful for the treatment of severe psoriasis, particularly the pustular and erythrodermic variants. Psoriatic nail changes and arthritis also may respond. Combining the drug with ultraviolet light therapy (Re-UVB, in the case of ultraviolet B radiation, or Re-PUVA, with psoralen plus ultraviolet A radiation) permits the use of lower doses of both acitretin and ultraviolet radiation. Other conditions for which the drug may be especially useful include congenital and acquired hyperkeratotic disorders, such as the ichthyoses and palmoplantar keratodermas, and severe lichen planus.

Побочные эффекты

Side effects are dose dependent and include elevation of triglycerides, hepatitis, hair loss, thinning of the nails, cheilitis, xerosis, and stickiness of the skin. Gemfibrozil (300 mg b.i.d.) corrects elevated lipid levels on this therapy.