<p>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.</p>