Mechanisms of the Comedolytic and Anti-Inflammatory Properties of Topical Retinoids
January 2005 | Volume 4 | Issue 1 | Original Article | 41 | Copyright © January 2005
Joseph B. Bikowsky MD
Background: Retinoids comprise a family of compounds with structures and mechanisms of action that resemble those of vitamin A
(retinol), an essential nutrient which plays a role in cell growth and differentiation. The retinoids, which interact with nuclear
receptors and affect gene transcription, have enormous therapeutic potential, particularly if they are receptor- and functionselective.
Tretinoin was the first topical retinoid employed for the treatment of acne. In recent years, other topical retinoids
for the treatment of acne have been designed from a disease-specific approach, with enhanced receptor and function selectivity,
which translates to improved therapeutic effects and more favorable tolerability. The properties that differentiate the
topical retinoids tretinoin, adapalene, and tazarotene have permitted clinicians to tailor acne treatment regimens for maximum
Tretinoin (all-trans-retinoic acid), considered a first-generation retinoid, acts by altering the milieu of the microcomedo and
influences desquamation of abnormal epithelium. Two receptor-selective synthetic retinoids, adapalene and tazarotene, may
be classified as third-generation retinoids. Adapalene, a derivative of naphthoic acid, has comedolytic, antiproliferative, and
anti-inflammatory properties. Tazarotene is a prodrug metabolized to tazarotenic acid that modulates cellular differentiation,
desquamation, and inflammation.