Study of the prophylactic effect of droperidol, alizapride, propofol and promethazine on spinal morphine-induced pruritus.

BACKGROUND: We have compared the use of alizapride, propofol, droperidol and promethazine for the prevention of spinal morphine-induced pruritus. METHODS: Three hundred ASA I or II women undergoing Caesarean section under spinal anaesthesia, in which morphine 0.2 mg was added to a local anaesthetic, were assigned randomly to receive i.v., in the operating room, just after delivery of the baby, alizapride 100 mg, propofol 20 mg, droperidol 1.25 mg, promethazine 50 mg or saline 2 ml (control group). In the postoperative period, the women were assessed for pruritus (absent, mild, moderate or severe) or other untoward symptoms by blinded observers. We used 95% confidence limits (95% CI) for the cumulative incidence of moderate and severe pruritus to compare the groups, and the NNT and 95% CI to compare droperidol, propofol and alizapride as for their effectiveness in preventing pruritus. For other untoward effects, the chi(2)-test was used, results being considered significant when P<0.05. RESULTS: The droperidol, propofol and alizapride groups had significantly lower incidences of pruritus compared with the control and promethazine groups, while the incidence of pruritus was similar among the patients assigned to the promethazine and control groups. As for the prevention of moderate and severe pruritus, droperidol had the lowest NNT (3.52; 95% CI: 3.37-3.67), followed by propofol (4.61; 95% CI: 4.45-4.77) and alizapride (5.43; 95% CI: 5.27-5.59). As for untoward effects, droperidol and promethazine increased the incidence of somnolence, which seemed more severe with promethazine. Otherwise, there were no differences between the groups. CONCLUSION: Droperidol, propofol and alizapride, in a decreasing order of effectiveness in the doses used in this study, reduced the incidence of pruritus induced by the use of morphine 0.2 mg intrathecally. On the other hand, promethazine 50 mg was shown to be ineffective.

Effect of intravenous alizapride on spinal morphine-induced pruritus.

BACKGROUND: This double-blind study was undertaken to determine whether alizapride inhibits spinal morphine-induced pruritus. METHODS: Eighty-four patients undergoing Caesarean section under spinal anaesthesia (100 mg of hyperbaric lidocaine 5% plus morphine 0.2 mg) were randomly allocated to one of two groups. Just after birth, alizapride-50 mg (alizapride group) or metoclopramide-10 mg (metoclopramide group) were injected i.v. Patients were assessed after surgery for pruritus (absent, mild, moderate or severe) or other untoward symptoms. RESULTS: In the metoclopramide group, pruritus was absent in 5 (12%) patients, mild in 23 (55%), moderate in 11 (26%), and severe in 3 (7%), while in the alizapride group, these incidences were, respectively, 5 (12%), 33 (79%), 4 (10%), and 0 (P=0.045, chi(2)-test). There was no difference in the incidence of side-effects, which were all minor. CONCLUSIONS: Alizapride reduced the severity of morphine-induced pruritus.

The inhibition of epidural morphine-induced pruritus by epidural droperidol.

UNLABELLED: IV droperidol inhibits epidural morphine-induced pruritus, but this effect disappears when the dose is increased from 2.5 to 5.0 mg. This study was performed to determine whether epidural droperidol would have a similar effect. In this double-blinded study, we enrolled 140 patients undergoing Cesarean delivery under epidural anesthesia who were randomly allocated to four groups. Anesthesia consisted of 150 mg of 0.5% bupivacaine with 1:200,000 epinephrine, with 2 mg of morphine and 0.0, 1.25, 2.5, or 5.0 mg of droperidol (Groups 1 to 4). During the postoperative period, patients were assessed for pruritus (absent, mild, moderate, or severe) and other untoward symptoms. The chi(2) test was used to compare the incidence of the side effects. For the analysis of pruritus, we used the Mantel-Haenszel test for linear association. Droperidol induced a dose-related reduction in the incidence of pruritus (P < 0.001). This reduction was independent of the incidence of somnolence, which increased with droperidol dose (P < 0.05 when the incidence of somnolence in Groups 1 and 4 was compared). We conclude that droperidol, in doses up to 5 mg epidurally, induces a dose-related reduction in the incidence of pruritus without inducing significant side effects. IMPLICATIONS: Epidural morphine is effective for pain control but yields some side effects, including pruritus, that can be severe. Studying patients undergoing Cesarean delivery, we found a dose-related reduction in the incidence of pruritus using epidural droperidol.

Inhibition of epidural morphine-induced pruritus by intravenous droperidol. The effect of increasing the doses of morphine and of droperidol.

BACKGROUND AND OBJECTIVES: Because the mechanism of inhibition of epidural morphine-induced pruritus by droperidol is not clear, this study was undertaken to determine the effects of larger doses of droperidol or morphine, or both. METHODS: A double-blind study was performed in 210 ASA I or II patients undergoing cesarean delivery, who were randomly assigned to six groups. All patients received epidural anesthesia with 0.5% bupivacaine containing 1:200,000 epinephrine, to which 2 mg (groups 1, 2, and 3) or 4 mg (groups 4, 5, and 6) morphine sulfate was added. Just after delivery, 2.5 mg droperidol was given intravenously to groups 2 and 5, and 5 mg was given to groups 3 and 6. During the postoperative period, the patients were assessed for the occurrence and severity of pruritus (classified as absent, mild, moderate, or severe) or other untoward symptoms. The groups were compared for the incidence of pruritus by the Mann-Whitney nonparametric test. RESULTS: The incidence of pruritus was significantly reduced only when the control group. (no droperidol) was compared with the group that received 2.5 mg droperidol, both when 2 mg and when 4 mg morphine was used. A 5-mg dose of droperidol had no inhibitory effect. There was no difference in the incidence of pruritus between use of 2 mg and 4 mg morphine. Other untoward effects of morphine either could not be observed or occurred with an incidence unaffected by either dose of droperidol. CONCLUSION: Pruritus caused by epidural use of 2 or 4 mg of morphine is inhibited by the intravenous use of 2.5 mg droperidol but not by a larger dose.

Inhibition of epidural morphine-induced pruritus by intravenous droperidol.

BACKGROUND AND OBJECTIVES: Our objective was to study in more detail our previous finding that intravenous droperidol inhibits pruritus induced by epidural morphine. METHODS: In a double blind study, 107 ASA I or II patients undergoing cesarean section received epidural anesthesia with 150 mg (30 ml) of 0.5% bupivacaine with 1:200,000 epinephrine and 2 mg of morphine hydrochloride in a single injection. They were randomly allocated to either receive (treated group, n = 54) or not receive (control group, n = 53) an intravenous injection of 2.5 mg of droperidol just after delivery. During the postoperative period, the patients were assessed for the occurrence and severity of pruritus or other possible untoward symptoms. Pruritus was classified as absent, mild, moderate, or severe. RESULTS: The incidence of pruritus in control group was absent, 26.4%; mild, 39.6%; moderate, 28.3%; severe, 5.7%; for the treated group, the incidences were, respectively: 59.2; 27.8; 13.0; and 0.0% (p = 0.0003; Mann-Whitney test). As for other side effects of morphine, nausea and vomiting had a similar incidence in the two groups; urinary retention could not be analyzed because of bladder catheterization, and constipation, herpes labialis and clinical evidence of respiratory depression were never observed. Droperidol produced a greater incidence of somnolence (2% in control and 17% in treated group--p < 0.02; Fisher's exact test), but it was never incapacitating. The incidence of hypotension was similar in the two groups. CONCLUSION: Intravenous droperidol reduces the incidence and severity of pruritus caused by epidural injection of morphine without inducing important side effects.