Nalbuphine hydrochloride (Nubain ® , 20 mg) was administered intramusculary for postoperative pain control to thirty three patients scheduled for open cholecystectomy. Quality and duration of analgesia, with adverse effects were evaluated for two subsequent doses of nalbuphine. First dose was administered at the end of surgery, the other dose as requested by the patient. Besides one skin allergic reaction there were not observed any serious adverse effects. Analgesia was not adequate in four and two patients after the first and second dose, respectively. The average duration of analgesia was 3,4 hours and 4,5 hours after the first and second dose, respectively. The principle side effect was sedation pronounced in 95% of patients, in 41% assessed as deep sedation (GCS 10–12). In 15% of patients there was observed postoperative nausea and vomiting, in one patient there was observed a psychomotoric distress. Nalbuphine can be safely used for moderate to severe pain control without the risk of respiratory or circulatory depression.

        Key words: postoperative analgesia – nalbuphine