Anti-emetic drug effects on cognitive and psychomotor performance: granisetron vs. ondansetron.

The central objectives of this study were to evaluate the cognitive, psychomotor and subjective effects of two anti-emetic drugs of established value in the prophylaxis of radiation induced nausea and vomiting. The drugs of interest were granisetron (Kytril, SmithKline Beecham Pharmaceuticals, Philadelphia, PA; 1 mg tablets/2 mg dose) and ondansetron (Zofran, Glaxo Welcome, Inc., Research Triangle Park, NC; 8 mg tablets/8 mg dose). The experimental approach, involving 24 active-duty military subjects, was a placebo controlled, double blind, crossover design with a positive control (prochlorperazine, 10 mg tablets/10 mg dose) condition. Testing was accomplished during the evening and early morning hours, between 1630 hours and 0230 hours. Therefore, fatigue stemming from an extended work period and a disrupted work/rest cycle was also part of the study design. Data were collected on the following: cognitive and psychomotor effects, affective state changes, temperature, serum drug levels, and side effects. The drugs of interest, granisetron and ondansetron, were extremely well tolerated, with no obvious side effects when compared to the placebo condition. Two of five cognitive tests detected a positive control effect and nearly all of the measurement instruments demonstrated a general fatigue effect, independent of the drug. There was no evidence of any cognitive, psychomotor or subjective state changes caused by either granisetron or ondansetron. It was concluded the anti-emetic drugs, granisetron or ondansetron, would not interfere with performance when given prophylactically to personnel at risk of exposure to radiation.