DOES POTENCY DETERMINE AMNESTIC EFFECTS OF BENZODIAZEPINES - A DOSE-RESPONSE COMPARISON OF FLUNITRAZEPAM AND NITRAZEPAM

This study was designed to explore whether differences in the psychomo tor, subjective and memory effects of different benzodiazepines (BDZ) relate to differences in their potencies. Two BDZs with similar kineti cs but different potencies were compared. Flunitrazepam (0.5 and 1.0 m g), nitrazepam (5 and 10 mg) or placebo were administered to 50 health y volunteers in a double-blind, parallel group designs. Subjects compl eted a test battery before and 1.5 h post-treatment. The higher dose o f the more potent BDZ, flunitrazepam, impaired episodic memory in rela tion to placebo. In contrast, differences in psychomotor and subjectiv e effects between BDZ were less clear. We conclude that a main caveat to the conclusion that potency plays a role in determining BDZ amnesti c effects is the possible contribution of sedation and differential ta sk sensitivities to apparent differential effects of BDZ compounds.