[Postoperative analgesia after cesarean section: sublingual buprenorphine versus subcutaneous morphine].

This study aimed to compare the efficacy and side-effects of sublingual buprenorphine, a synthetic opioid agonist antagonist, with those of subcutaneous morphine. Fifty ASA class 1 patients were included in the study after having given their informed consent. Caesarean section was carried out under epidural block with 0.5% bupivacaine; no opioids were used during the procedure. The first dose of opioid was given 2 h after the first dose of bupivacaine. Patients were randomly given either 10 mg morphine (n = 25) or 0.4 mg buprenorphine (n = 25), followed by the same dose every 6 h for 36 h. When analgesia was insufficient, tablets containing dextropropoxyphene and paracetamol were given. No attempt was made to blind the study to the patient, but the investigator assessing pain was unaware of the drug given to the patient. Pain intensity was assessed before, and 2 h after each dose of opioid with a 100 mm visual scale, as well as systolic, diastolic and mean arterial blood pressures, heart and breathing rates, and SpO2. Side-effects (pruritus, nausea, vomiting, drowsiness) were also noted. In 2 patients in each group, the protocol was stopped before the 36th h, but after the fourth dose, either because of side-effects, or at the patient's request. Results were similar in both groups of patients, whether for degree of pain relief, or physiological effects. There was no clinically detectable respiratory depression. Duration and intensity of episodes of arterial oxygen desaturation, and the incidence of nausea, were similar in the 2 groups; pruritus was more common in the morphine group.(ABSTRACT TRUNCATED AT 250 WORDS)