Avoiding psychic adverse effects during induction of neurolept anaesthesia with levomepromazine. A double-blind study of levomepromazine and droperidol.

Levomepromazine 0.1 mg/kg or droperidol 0.15 mg/kg for induction of neurolept anaesthesia were compared in a double-blind prospective study of 60 patients undergoing upper abdominal surgery. On the morning after surgery, eight of 30 patients (26.7%) who received droperidol remembered having had unpleasant anxiety, or nightmarish or panicky experiences during induction of anaesthesia, whereas only one of 30 patients (3.3%) receiving levomepromazine experienced such unpleasant adverse effects (P less than 0.01). During anaesthesia, the patients induced with levomepromazine needed somewhat less fentanyl, had somewhat less pain intensity, during the first 3 h after surgery, and they required the first postoperative dose of morphine 1.5 h later than the patients receiving droperidol (P less than 0.02). There was no difference in the number of patients receiving naloxone at the end of anaesthesia in the two groups. However, 21 of 30 patients (70%) in the levomepromazine group and only seven of 30 patients (23.3%) in the droperidol group were given physostigmine for arousal at the end of anaesthesia (P less than 0.01). There was no difference between the two groups in the occurrence of postoperative nausea, restlessness, hallucinations, or sedation in the recovery ward. This study shows that levomepromazine is superior to droperidol for induction of neurolept anaesthesia because it gives less psychic adverse effects, more analgesia, and a deeper sedation, which is easily reversed with physostigmine at the end of anaesthesia.