The effect of ondansetron on the pharmacokinetics and pharmacodynamics of temazepam.

The objective of this study was to determine the effects of ondansetron on the pharmacokinetics of temazepam and on pharmacodynamics relevant to its use as oral premedication. Twenty-four healthy volunteers (12 of each sex) were administered the following oral treatments in a randomised, double-blind crossover design: temazepam 20 mg plus placebo; or temazepam 20 mg plus ondansetron 8 mg. Blood samples were taken for plasma temazepam assay at intervals up to 32 h after administration. In addition, a brief battery of psychomotor tests was administered 1 h prior to dosing and 1 and 4 h after dosing. Analysis of the derived pharmacokinetic parameters showed no differences between the treatments described above. Analysis of data from the dynamic measures likewise showed no difference between the treatments. It was concluded that the co-administration of ondansetron did not influence the pharmacokinetics or pharmacodynamic actions of temazepam.