Retrospective analysis of postoperative nausea and vomiting to determine antiemetic activity of droperidol added to propofol: a possible drug interaction.

Propofol decreases the frequency of postoperative nausea and vomiting. We investigated whether its antiemetic activity could be improved further by coadministration of droperidol. We retrospectively reviewed the records of 266 women who underwent laparoscopic operations with nitrous oxide anesthesia and thiopental or propofol induction. The records were screened for frequency and time of occurrence of nausea and vomiting, concurrent drug use, duration of surgery, and times of recovery room admission and discharge. The combination of droperidol and thiopental decreased the frequency of nausea and vomiting over droperidol plus propofol, propofol alone, and thiopental alone. The addition of droperidol to propofol anesthesia doubled the frequency of multiple nausea and vomiting episodes, suggesting a possible interaction between the drugs. We cannot recommend that droperidol be added to propofol anesthesia for prophylaxis of postoperative nausea and vomiting.