Zolpidem and promethazine in pre-anaesthetic medication. A pharmacopsychological approach

This study dealt with the question: What are the effects of different doses of the benzodiazepine-like agent zolpidem and the phenothiazine derivative promethazine on mood in pre-anaesthetic medication? Subjects were 192 female and male patients awaiting elective surgery. Two drugs were administered to the patients in the evening before anaesthesia according to a 3 x 2 factorial randomized double-blind design. The first drug factor was zolpidem (8.03 vs. 16.06 mg) versus placebo. These drugs were combined with the second drug factor, either promethazine (50 mg) or placebo. In summary, the results confirm the hypothesis that zolpidem 8.03 mg can induce paradoxical effects, especially of anxiety, 1 h after application. When the dosage is doubled, no adverse effects are found, but there are no effects different from placebo either. Men could probably be described as a risk population for the adverse effects of zolpidem 8.03 mg. Furthermore, selective deactivating effects of promethazine 50 mg were shown in this study. In addition to these anaesthesiological aspects, this study showed promethazine to be useful as a research tool, suitable as a reference drug to detect deactivating effects. The multidimensional self-report inventory BSKE(EWL) (Befindlichkeitsskalierung durch Kategorien und Eigenschaftswörter) detected the expected drug effects, indicating that this instrument is suitable for further pharmacopsychological research.