Morphine-induced Pruritus Research Articles

Ondansetron is Effective to Treat Spinal or Epidural Morphine-Induced Pruritus

Ondansetron is Effective to Treat Spinal or Epidural Morphine-Induced Pruritus

ONDANSETRON IS EFFECTIVE TO TREAT SPINAL OR EPIDURAL MORPHINE-INDUCED PRURITUS

S280 BACKGROUND: Spinal and epidural morphine are frequently associated with pruritus. Isolated case reports reported that ondansetron may be effective in this context. The aim of this study is to investigate the efficacy of ondansetron to treat this side-effect. METHODS: In a prospective, randomized, double-blind, placebo-control study, 100 patients having pruritus (> 4 on a visual analogue scale form 0 = no pruritus, to 10 = worst pruritus imaginable) after spinal or epidural morphine application, received either 8mg i.v. ondansetron (ondansetron group) in 100ml NaCl 0.9% or the vehicle (placebo group). A decrease of more than 4 on the VAS 60min after treatment was given, was considered a success. Change in pain and sedation levels, hemodynamic values and other side-effects, were regularly checked. The presence or absence of pruritus was assessed for the last time 24h later. RESULTS: The 2 groups were similar for demographic data, the route of morphine administration, and severity of pruritus at the beginning of the study. The ondansetron group showed a success rate of 70% versus 30% for the placebo group (P < 0.05). Among the successfully treated patients 3 (9%) in the ondansetron group and 6 (40%) in the placebo group reported the recurrence of pruritus (P < 0.05). Among the successfully treated patients no one complained of residual pruritus 24h later. No changes in pain or sedation levels were noted. Hemodynamic values remained stable, hemoglobin oxygen saturation did not decrease and no other side-effects were observed. CONCLUSION: The administration of ondansetron 8mg i.v. is an effective treatment for spinal or epidural morphine-induced pruritus. In this clinical condition the treatment is safe and well tolerated.

Treatment of Intrathecal Morphine-Induced Pruritus Following Cesarean Section

ALHASHEMI, JAMAL A.; CROSBY, EDWARD T.; GRODECKI, WLODZIMIERZ; DUFFY, PETER J.; HULL, KATHRYN A.; GALLANT, CATHY Author Information

Subhypnotic Doses of Propofol Relieve Pruritus Induced by Epidural and Intrathecal Morphine

We investigated the efficacy of subhypnotic doses of propofol for spinal morphine-induced pruritus in a prospective, randomized, double-blind, placebo-controlled study. Fifty patients, ASA physical status 1-3, with spinal morphine-induced pruritus were allocated to receive either 1 ml propofol (10 mg) or 1 ml placebo (Intralipid) intravenously after gynecologic, orthopedic, thoracic, or gastrointestinal surgery. In the absence of a positive response, a second drug treatment was given 5 min later. The persistence of pruritus 5 min after the second treatment dose was considered a treatment failure. All failures then received, in an open fashion, a supplementary dose of propofol (10 mg) and were reevaluated 5 min later. Both groups were well matched. The success rate was significantly greater in the propofol group (84%) than in the placebo (16%) group (P less than 0.05). Ninety percent of the treatment failures in the placebo group were successfully treated by a supplementary dose of 10 mg propofol. Eight percent of the patients (4% in each group) were resistant to all treatments, including naloxone 0.08 mg intravenously. Three patients had a slight increase in sedation in the propofol group versus none in control (not significant). The beneficial effect of treatment was longer than 60 min in 85% of patients in the propofol group and in 100% of the controls (not significant). These results suggest that propofol in a subhypnotic dose is an efficient drug treatment for spinal morphine-induced pruritus. At the dose administered (10 mg), side effects were rare and minor.

Reversal of Epidural Morphine-Induced Respiratory Depression and Pruritus with Nalbuphine

Reversal of Epidural Morphine-Induced Respiratory Depression and Pruritus with Nalbuphine

The Effect of Epinephrine in Local Anesthetic on Epidural Morphine-Induced Pruritus

Department of Anesthesia, University of British Columbia and Grace Hospital, Vancouver, British Columbia, Canada

The effect of epinephrine in local anaesthetic on epidural morphine-induced pruritus.

The severity of epidural morphine-induced pruritus was evaluated following the addition of epinephrine to the local anaesthetic solution used for Caesarean section anaesthesia. The local anaesthetic solutions used were: Group I--0.5 per cent bupivacaine plain--20 patients. Group II--0.5 per cent bupivacaine with 1:400,000 epinephrine--25 patients. Group III--0.5 per cent bupivacaine with 1:200,000 epinephrine for the 3 ml "test dose" followed by 0.5 per cent bupivacaine plain for anaesthesia--21 patients. The severity of the pruritus, as measured by completion of a visual analogue "itch scale" and by requests for medication for pruritus, was statistically significantly greater in both groups in which epinephrine was added. This effect was not dose-related, as the "test dose" group (15 micrograms epinephrine) experienced the most severe itch. This latter difference was also statistically significant (p less than 0.05).

Potentiation of histamine-induced itch and flare responses in human skin by the enkephalin analogue FK-33-824, beta-endorphin and morphine.

The effect of various opioid or putative neurotransmitter peptides on histamine-induced itch and flare responses was studied in humans after intradermal injection. Significant enhancement of the histamine responses was induced by the stable methionine-enkephalin analogue FK 33-824, beta-endorphin and morphine. The putative neurotransmitters substance P and vasoactive intestinal polypeptide (VIP)--which moreover are potent histamine liberators--had no enhancing effect. The potentiation induced by FK 33-824 was induced neither by local pretreatment with Compound 48/80 to deplete the local stores of mast-cell-bound histamine, nor by oral pretreatment with indomethacin to inhibit prostaglandin formation in the skin. Thus, the enhancement did not seem to be due to histamine release or to prostaglandin formation and the mechanism of the effect remains to be shown. The specific morphine antagonist naloxone did not inhibit the potentiation by FK 33-824, which might indicate that ordinary opiate receptors were not involved. The results support the idea that pain and itch are qualitatively separate processes and suggest possible mechanisms of morphine-induced pruritus. The findings are of particular interest in view of recent reports on the presence of methionine-enkephalin in Merkel cells.