Pharmacokinetics of the retinoids isotretinoin and etretinate

Decreased Isotretinoin Efficacy during Acute Alcohol Intake

“…Isotretinoin has a complex me tabolism. as 4-oxo-isotretinoin is its major metabolite and a glucuronized compound is excreted in bile and urine [6]. In our case, temporary acute alcohol consumption in a patient with a past history of chronic alcohol ingestion might have induced hepatic microsomal enzymes transitorily, thus increasing retinoid biotransformation and both decreasing therapeutic efficacy and undesirable secondary effects.…”

Sarcoid-Like Granuloma Following Prolonged Etretinate Treatment

“…Less than 1% have presented pyogenic gra nuloma-like lesions and smaller numbers crythcma-multiforme-like lesions [1,2], An unusual side effect of etreti nate was a nodular prurigo-like eruption [3]. Brazzell and Colburn [4] confirm the storing of etretinate in adipose tis sue until its elimination after prolonged treatments. Detec tion of blood traces, even 3 years after ceasing therapy, have been reported [5].…”

Oral Liarozole as a Catabolic Inhibitor Potently Increases Retinoic Acid in vivo: First Experience from an Ongoing Therapeutic Trial in Highly Malignant Primary Brain Tumors

“…In contrast to 4-hydroxy-retinamide or fenretinide [11,12], retinol and retinol-binding protein have not been markedly altered with increased total plasma retinoic acids until now. Maximum plasma levels occur 1-6 h after oral administration [13,14], with a biphasic mean elimination half-life of 1.3 h for 13-cis-RA and 17 h for 4-oxo-13-cis-RA. Under 13-cis-RA monotherapy, plasma concentrations have remained stable for 25 days [14].…”

“…Maximum plasma levels occur 1-6 h after oral administration [13,14], with a biphasic mean elimination half-life of 1.3 h for 13-cis-RA and 17 h for 4-oxo-13-cis-RA. Under 13-cis-RA monotherapy, plasma concentrations have remained stable for 25 days [14]. Due to a short plasma half-life of liarozole, dosedependent retinoid side effects can be controlled easily during combined therapy and have never necessitated any glucocorti coid intervention [15].…”