Postcesarean analgesia with spinal Morphine, Clonidine, or their combination

In this randomized, double-blind trial in 240 women, we investigated the analgesic efficacy and duration of subarachnoid fentanyl 15 [mu]g with morphine, clonidine, or both morphine and clonidine for cesarean delivery. A dose-finding analysis showed similar postoperative efficacy and side effects for groups receiving morphine 100 [mu]g with clonidine 60, 90, or 150 [mu]g. Data from these groups were combined (MC60-150, n = 113) and compared with groups receiving morphine 100 [mu]g (n = 39), clonidine 150 [mu]g (n = 39), or morphine 100 [mu]g plus clonidine 30 [mu]g (n = 41). The four groups differed in the time to patient-controlled morphine use and cumulative morphine consumption (P <0.0001 and P <0.001, respectively), with the longest duration and smallest dose in MC60-150. Pain scores were significantly different among groups. Onset of sensory block, ephedrine requirement and incidence of hypotension, patient satisfaction, and recovery were similar. Groups receiving clonidine had greater sedation, those receiving morphine had more severe pruritus, and group MC60-150 showed a trend to more vomiting intraoperatively. Compared with morphine 100 [mu]g or clonidine 150 [mu]g alone, the combination of subarachnoid morphine 100 [mu]g and at least 60 [mu]g of clonidine was found to increase the duration of postcesarean analgesia, reduce opioid requirement, and increase intraoperative sedation.