Nalbuphine and pentazocine in an opioid-benzodiazepine sedative technique: a double-blind comparison.

Sedation by a combination of an opioid drug such as pentazocine with a benzodiazepine is commonly used for minor surgical and investigative procedures. Nalbuphine is a newer drug which, like pentazocine, is an opioid agonist-antagonist. Its actions are similar, but it has theoretical advantages in its profile of cardiovascular side effects. Nalbuphine or pentazocine in combination with diazepam were compared as components of a sedative technique for invasive radiology. The doses used were in the ratio of 2.5:1--ie nalbuphine 0.2 mg kg-1 and pentazocine 0.5 mg kg-1. Both regimens gave satisfactory results, and no difference could be detected between them in terms of sedation, analgesic efficacy, cardiovascular or respiratory changes, or recovery. Nalbuphine provides a safe and effective alternative to pentazocine in this situation. The study confirmed the need for caution because of the respiratory depressant effects of both drugs.