Effects of Foods on the Pharmacokinetics and Clinical Efficacy of Quazepam

: The effects of foods on the pharmacokinetics and clinical efficacy of quazepam, a benzodiazepine derivative, in healthy persons were examined. Six healthy Japanese male subjects were randomly divided into three groups and each subject was treated with quazepam under the following three conditions by the crossover method. For the fasting state, subjects were administered 15 mg quazepam 11 hours after a meal. For the postprandial state, subjects were administered 15 mg or 30 mg quazepam 2 hours after a meal. Mean peak plasma concentration (Cmax) of quazepam was significantly higher [1.6-2.8 fold] with administration 2 hours after a meal than 11 hours after a meal. However, in regard to 15 mg of quazepam administration, the area under the curve (AUC) did not differ between administration 2 hours after a meal and 11 hours after a meal. In addition, differences were observed neither in other pharmacokinetic parameters or blood metabolite concentration under all of the study conditions, nor in clinical evaluation of subjective symptoms, complete blood count, or biochemical analyses between administrations 2 and 11 hrs after a meal. The present study showed that administration 2 hours after a meal did not affect subjective symptoms or physical functions so much; therefore it suggested favorable tolerance of this drug. However, it was also suggested that, in actual clinical use, it is important to evaluate the physical function including measurements of vital signs and hematological test results, carefully considering the effects of foods and daily life-style.