category X drug

(redirected from Class X Drug)
A drug with a very high teratogenic risk to a fetus, based on controlled animal studies, which is contraindicated for use during pregnancy
Examples Accutane, thalidomide, vitamin A congeners, Xanax
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

category X drug

Pharmacology A therapeutic with known teratogenicity which is contraindicated for use during pregnancy–eg, vitamin A congeners–for severe acne–which cause a characteristic syndrome in neonates. See Vitamin A embryopathy.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.