Saccadic eye movements as a quantitative measure of the sedative effect of drugs

Abstract

On separate test days, seven healthy test subjects were given a single oral dose each of moclobemide (150 mg), desipramine (50 mg), amitriptyline (50 mg) or placebo in randomized order and under double-blind conditions. Horizontal 30° saccades were recorded 30 minutes prior to administration, and 30, 60 and 90 minutes, and 2, 3, 6 and 9 hours thereafter. The amplitude, peak velocity and duration of 15 saccades were recorded during each session. Moclobemide had only a very minor effect on the normal state of alertness: a significant, moderate degree of fatigue was noted only two hours after administration. In comparison with placebo, desipramine increased alertness slightly by lessening physiological fatigue under the test conditions. Amitriptyline caused relatively marked fatigue which peaked two hours after the tablet was taken and continued, decreasing gradually for up to nine hours.

Key Words:

• moclobemide
• desipramine
• amitriptyline
• placebo
• saccades
• infrared oculography
• sedation