Etretinate metabolism

K. M. Knights, R. Gasser, W. Klemisch, In vitro Metabolism of Acitretin by Human Liver Microsomes Evidence for an Acitretinoyl-Coenzyme A Thioester Conjugate in the Transesterification to Etretinate , Biochem. Pharmacol. 2000, 60, 507-516. 

Acitretin has the advantage of a shorter half-life. 2 hours after a single dose and 50 hours after multiple doses. It is. however, more susceptible to conversion to 13-ci.t-etretin. Thus, it appears that the e.stcr provides metabolic stability. 

Adtretin. Acitretin (Soriatane) is a yellow to greenish-yellow powder. It is the active species of etretinate. After absorption, acitretin is extensively metabolized and also undergoes isomerization to its 3-tis isomer. Acitretin is less lipid soluble than etretinate and thus is eliminated fa.ster by the body. The elimination half-life is SO hours. 

Not understood. It has been suggested that etretinate or isotretinoin may increase the rate of metabolism of warfarin. ... 

Uncertain. An in vitro study using human liver microsomes found that concentrations of 100 micromol of acitretin, etretinate and isotretinoin inhibited the total ciclosporin metaholism and total primary ciclosporin metabolite production to the same extent (32 to 45%). These figures suggest that the retinoids may inhibit ciclosporin metabolism. However, another in vitro study using human liver microsomes did not find that etretinate inhibits the metabolism of ciclosporin. ... 

Webber IR, Back DJ. Effect of etretinate on cyclosporin metabolism in vitro. BrJ Dermatol... 

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