Premedication with oral and rectal diazepam.

It has been postulated that esophageal retention of diazepam tablets is a problem of clinical significance, and that rectal administration is an advantageous alternative. To test this hypothesis, 100 patients were randomly allocated to premedication with either 15 mg diazepam orally or 10 mg diazepam as a rectal solution. A double dummy technique was used. A sedative effect was seen in 23 (50%) of the patients premedicated by mouth (O-group), but only in eight (20%) of those premedicated rectally (R-group) (P less than 0.05). Four patients (9%) in the O-group and seven (18%) in the R-group were unacceptably anxious before induction (n.s.). The plasma concentrations in the tablet group were nearly twice the concentrations found in the rectal-solution group, but no correlation between premedication effect and plasma concentration was found. Timing of premedication was very inaccurate, and this favored oral administration because of a more prolonged effect. No evidence of persistent esophageal retention was found.