Morphine-induced Pruritus Research Articles

Incidence and influential factors of postoperative pruritus in morphine-based intravenous patient-controlled analgesia

Background: Pruritus is a distressing symptom of systemic opioid analgesia that responds poorly to conventional antipruritus treatments. This study aimed to determine the incidence and risk factors for postoperative pruritus using intravenous patient-controlled analgesia (IV-PCA). Methods: Opioid-naïve patients who underwent morphine-based IV-PCA for postoperative pain at a tertiary center between January 1, 2020, and June 30, 2023, were included retrospectively. The primary outcome was pruritus within 72 h after surgery. Cumulative morphine consumption and pain numerical rating scores were measured to evaluate the potential impact of pruritus on postoperative pain control. Results: A total of 1,696 patients were enrolled, of whom 119 (7.0%) developed pruritus during the study period. Five independent factors for pruritus were identified, including intraoperative uses of hydroxyethyl starch solutions [adjusted odds ratio (aOR): 0.13, 95% confidence interval (CI): 0.04–0.43], lockout interval of IV-PCA (aOR: 0.50, 95% CI: 0.27–0.94, on base-2 logarithmic scale), droperidol addition to morphine solutions (aOR: 0.53, 95% CI: 0.35–0.81), cumulative morphine dose (aOR: 1.76, 95% CI: 1.47–2.12, on base-2 logarithmic scale), and postoperative uses of antihistamines (aOR: 2.90, 95% CI: 1.83–4.60) (c-statistic = 0.745). Patients with pruritus had higher postoperative morphine consumption (median: 67.5 mg, interquartile range: 38.3–94.0 vs. 38.0 mg, 21.0–65.4, p<0.0001) but similar pain intensity compared to those without pruritus. Conclusion: Increasing the lockout interval and the droperidol regimen may protect patients from morphine-induced pruritus after IV-PCA. Further studies are warranted to clarify the mechanisms underlying the anti-pruritus effects of hydroxyethyl starch.

Comparison of the ED50 of prophylactic butorphanol in preventing morphine-induced pruritus with or without palonosetron: a prospective, double-blinded, randomized dose–response trial using an up-down sequential allocation method

Background Butorphanol has been used to reduce the incidence and severity of neuraxial morphine-induced pruritus. Palonosetron is a commonly used antiemetic for the prevention of postoperative nausea and vomiting. The aim of our study was to compare the effective dose in 50% of subjects (ED50) of intravenous butorphanol infusion with or without a single intravenous bolus of palonosetron for preventing pruritus induced by epidural administration of morphine. Methods A total of 120 parturients were randomly assigned to receive an intravenous bolus injection of palonosetron plus continuous infusion of butorphanol (Group P + B) or an intravenous bolus of saline plus continuous infusion of butorphanol (Group B) after epidural administration of morphine. The antipruritic effect was graded as satisfactory (numerical rating scale (NRS) of pruritus ≤3) or unsatisfactory (NRS >3) within 48 h after morphine treatment. The first patient in each group received butorphanol infusion at a rate of 4 µg/kg/h. The infusion dose for each subsequent patient in the corresponding group was increased by 0.2 µg/kg/h after an unsatisfactory response or decreased by 0.2 µg/kg/h after a satisfactory response. The ED50 was calculated for each group and compared using up-down sequential analysis. Results The ED50 (mean [95% confidence interval (CI)]) of the dose of intravenous butorphanol infusion for preventing moderate to severe pruritus was lower in Group P + B (3.29 µg/kg/min [3.25–3.34 µg/kg/min]) than in Group B (3.57 µg/kg/min [3.47–3.67 µg/kg/min]) (p < 0.05). Conclusions Under the conditions of the present study, a prophylactic use of 0.25 mg palonosetron reduced the ED50 of prophylactic infusion of butorphanol by approximately 8% to achieve a satisfactory antipruritic effect after epidural morphine for post-caesarean analgesia.

Alleviating morphine-induced itching while sustaining its analgesic efficacy: Esketamine as a potential co-administrating choice

Morphine is one of the most commonly used and effective analgesic drugs in clinical practice. Morphine injected directly into the epidural and subarachnoid space acts directly on the central nervous system compared to oral or intravenous administration. This route of morphine delivery requires only a small dose to achieve satisfactory analgesia and greatly reduces the risk of adverse effects. However, morphine-induced itching significantly limits the clinical use of morphine and the maximization of its analgesic effects. Drugs commonly used worldwide to treat morphine-induced pruritus have different degrees of limitations. N-Methyl-D-aspartate (NMDA) receptors are involved in the mechanisms associated with morphine-induced itching. Theoretically, esketamine, an NMDA antagonist, which is commonly used in clinical practice to exert analgesic and sedative effects and contributes to circulatory stability, has the potential to effectively relieve morphine-induced itching without compromising its analgesic effects. In this paper, we discuss the possibility of co-administration of esketamine in cases of morphine-induced pruritus based on the current clinical situation and relevant mechanisms, with the intention of developing novel therapeutic options for morphine-induced pruritus.

Effect of intravenous administration of hydroxyzine hydrochloride on intrathecal morphine-induced pruritus after cesarean section.

Effect of intravenous administration of hydroxyzine hydrochloride on intrathecal morphine-induced pruritus after cesarean section.

Randomized Double-Blind Trial Comparing Efficacy of Intravenous Nalbuphine vs Intrathecal Nalbuphine for Prevention of Intrathecal Morphine Induced Pruritus in Orthopaedic Surgeries

Intrathecal morphine provides excellent postoperative pain relief but results in pruritus in 30-60% of patients. Nalbuphine, an opioid agonist-antagonist prevents intrathecal morphine-induced itch when given by intravenous route. In this study, we compared efficacy of intrathecal and intravenous nalbuphine for the prevention of intrathecal morphine-induced pruritus. 90 patients were randomly divided into two groups. IT group received 100 mcg of morphine with 400 mcg of nalbuphine intrathecally. IV group received 100 mcg of morphine intrathecally and 400 mcg of nalbuphine intravenously. Incidence of itching, respiratory depression, hypotension, nausea, vomiting, sedation and analgesia were compared between the groups every 4th hourly for 24 hours. Data were analyzed with Chi-square test and Mann-Whitney test. Incidence of itching in 24 hours period was 11.6% (5 patients) in IV group and 4.8% (2 patients) in IT group which was comparable. (P= 0.250) Two patients in IV group had intractable itching requiring naloxone. Incidence of itching at all time intervals was comparable between the groups. Analgesia was prolonged in IV group (P=0.03) Incidence of nausea, vomiting, sedation and respiratory depression was comparable. We conclude that intrathecal nalbuphine and intravenous nalbuphine were equally effective in preventing intrathecal morphine induced pruritus. The duration of analgesia was more when nalbuphine was given by IV route as compared to IT route.

Prevention and Treatment of Neuraxial Morphine-Induced Pruritus: A Scoping Review.

The addition of morphine to neuraxial anaesthesia leads to improved postoperative analgesia and lower opioid consumption, but is often accompanied by pruritus. Studies on preventing or treating pruritus show contradictory results. Our objective was to identify effective drugs for the prevention or treatment of pruritus by a scoping review of clinical trials. A systematic literature search was conducted in PubMed, Embase and Web of Science. We identified clinical trials investigating the prevention or treatment of neuraxial morphine-induced pruritus in adults. Systematic reviews and meta-analyses were screened for eligible studies. One-hundred-and-four articles were included covering 13 pharmacological groups. We conclude that dopamine antagonists, µ-opioid agonist/antagonists and neuraxial or orally administered µ-opioid antagonists prevent pruritus caused by neuraxial morphine regardless of the timing of administration. In the reviewed literature, 5HT3-antagonists prevent neuraxial morphine-induced pruritus when administered before morphine administration. For the treatment of neuraxial morphine-induced pruritus, only nalbuphine appears to be consistently effective. More research is needed to find the most effective doses and the optimal timing of the effective medication.

The Incidence of Itching in Thoracic Epidural Morphine Applications: Can Laboratory Parameters Be Effective in Predicting Itching?

BackgroundEpidural morphine, a powerful analgesic, also causes significant itching in patients. This study aimed to determine the incidence of thoracic epidural morphine-induced pruritus (EMIP) after thoracotomy and to investigate preoperative laboratory parameters for predicting itching in patients who received thoracic epidural morphine (TEM).MethodsThe patients were divided into two groups. The itching (+) group consists of patients who developed itching (n=31). The no-itching (-) / control group (n=31) was selected among patients who did not develop itching after TEM. Preoperative hemogram values, neutrophil/lymphocyte rate (NLR), platelet/lymphocyte rate (PLR), lymphocyte/monocytes rate (LMR), preoperative and postoperative alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (ALP), gamma-glutamyl transferase values, and whether there was itching in the first 48 hours after surgery were determined.ResultsThe incidence of thoracic EMIP after thoracotomy was 7.9%. While preoperative and postoperative ALP was found to be lower in patients with itching compared to those without itching. The cut-off value for preoperative/postoperative ALP was 84.5/53. Decreased white blood cell (WBC) could predict pruritus with a borderline statistical significance.ConclusionsThe incidence of EMIP after thoracotomy was lower compared to other literature data. Infusion of morphine only into the epidural area may cause a low incidence of EMIP. Laboratory parameters ALP and WBC can predict EMIP, but other hemogram parameters, NLR, LMR, and PLR cannot predict EMIP.

25853 Efficacy and safety of oral nalbuphine extended release in prurigo nodularis: Results of a phase 2 randomized controlled trial with an open-label extension phase

Background: Prurigo nodularis (PN) is a chronic dermatologic condition associated with severe itch. Currently, there are no approved disease-specific drugs. The synthetic opioid nalbuphine, a dual-acting μ-antagonist and κ-agonist, has shown antipruritic efficacy in morphine-induced pruritus, uremic pruritus, and in a preliminary trial in PN.

Medications for the prevention of pruritus in women undergoing cesarean delivery with Intrathecal morphine: A systematic review and bayesian network meta-analysis of randomized controlled trials

PurposeIntrathecal morphine-induced pruritus can cause significant discomfort in parturients and is refractory to conventional antipruritic treatment. This systematic review and network meta-analysis evaluates the effectiveness of the medications used for prevention of intrathecal (IT) morphine-induced pruritus after cesarean delivery under spinal anesthesia. MethodsA literature search was conducted from 1946 up to October 2019. We included all randomized controlled trials (RCTs) that compared medications used for prevention of pruritus with a control group in women undergoing cesarean delivery under spinal anesthesia with IT morphine. The primary outcome examined was the incidence of pruritus up to 24 h after cesarean delivery. Dichotomous data were extracted and summarized using odds ratios (OR) and 95% credible intervals (CrI) with Bayesian random effects network meta-analysis model. The GRADE approach was used to evaluate quality of the studies and effect evidence. ResultsOf the 26 studies included in the systematic review, 21 studies with a total of 2594 patients were included in the network meta-analysis [prophylaxis, n = 1603 (62%) vs. control, n = 991 (38%)]. These studies investigated seven classes of drugs including serotonin-receptor antagonists, dopamine-receptor antagonists, opioid agonist-antagonists, opioid-receptor antagonists, histamine-receptor antagonists, propofol and celecoxib. The network meta-analysis showed that serotonin-receptor antagonists' prophylaxis [control vs. prophylaxis: 60% vs. 47%; OR (95% CrI): 2.69 (1.43–5.36)] and opioid agonist-antagonists prophylaxis [control vs. prophylaxis: 72% vs. 47%; OR (95% CrI): 4.57 (1.67–12.91)] decreased the incidence of pruritus compared to the control group. Although all included studies were at low risk of bias, the quality of the overall network meta-analysis pooled estimates was low. ConclusionThis bayesian network meta-analysis of RCTs demonstrates serotonin-receptor antagonists and opioid agonist-antagonists may prevent pruritus in women undergoing cesarean delivery with intrathecal morphine compared to control group. However, further RCTs of adequate power and clearly defined end points are warranted.

Antipruritic effects of electroacupuncture on morphine-induced pruritus model mice through the TLR2/4-MyD88-NF-κB pathway.

Pruritus is one of the common side effects of intrathecal or epidural injection of opioids. The aim of this study was to test the antipruritic effect of acupuncture and its possible mechanism. We used electroacupuncture (EA), toll-like receptor (TLR)2/4 antagonist sparstolonin B (SsnB), and TLR2/4 agonist peptidoglycan (PGN) to precondition female wild-type BALB/c mice, and then prepared a morphine-induced pruritus model. The mRNA and protein expression levels of TLR2, TLR4, MyD88, and NF-κB were detected by RT-PCR and western blotting. The contents of interleukin (IL)-1, IL-6, IL-12, IL-10, and tumor necrosis factor-α in serum were measured by ELISA assays. Flow cytometry was performed to analyze the ratio of M1-phenotype to M2-phenotype macrophages. Our results showed that EA preconditioning improved pruritus; reduced the expressions of TLR2, TLR4, MyD88, and NF-κB both at the mRNA and protein levels (P<0.05); reduced the expression of proinflammatory cytokines IL-1, IL-6, IL-12, and tumor necrosis factor-α; and increased the expression of anti-inflammatory cytokine IL-10 (P<0.05). EA promoted M2-phenotype macrophage differentiation. Moreover, these results showed no significant difference between the SsnB group and the EA+SsnB group (P>0.05), but showed a significant difference between the PGN group and the EA+PGN group (P<0.05). Therefore, we propose that EA may be involved in the remission of pruritus in morphine-induced pruritus model mice through the TLR2/4-MyD88-NF-κB pathway. EA is a potential therapeutic treatment for pruritus.

Acupuncture for reducing pruritus induced by intrathecal morphine at elective cesarean delivery: a placebo-controlled, randomized, double-blind trial

BackgroundIntrathecal morphine is a standard postoperative analgesic administered after cesarean delivery, but frequently causes pruritus. Acupuncture reportedly resolves refractory pruritus in certain patients. The aim of the study was to investigate the effectiveness of acupuncture in preventing pruritus induced by intrathecal morphine. MethodsThirty parturients received intrathecal hyperbaric bupivacaine (12 mg), fentanyl (10 µg), and morphine (150 µg) for spinal anesthesia at elective cesarean delivery at term. Patients were randomly divided into the acupuncture group (n=15) and the control group (n=15). In the acupuncture and control groups, certified acupuncturists inserted either indwelling press needles or sham needles, into Hegu (LI4), Neiguan (PC6), Quchi (LI11), and Zhigou (SJ6) on both arms the day before surgery. Needles were removed 48 hours postoperatively. The primary outcome was the incidence of postoperative pruritus. Adverse effects including nausea and vomiting were also investigated. ResultsThere were no significant differences between the acupuncture group and the control group in the incidence of pruritus (67% vs. 67%, P=1.000, RR 1.0 [95% CI 0.60 to 1.66]) or the requirement for antipruritic therapy (6.7% vs. 20.0%, P=0.283, RR 0.33 [95% CI 0.04 to 2.85]). The incidence of postoperative nausea in the acupuncture group versus control group was 40.0% vs. 13.3%, P=0.099, RR 3.0 [95% CI 0.72 to 12.6]). The postoperative analgesic effect was comparable. ConclusionPreoperatively administered acupuncture using press needles did not decrease intrathecal morphine-induced pruritus or the requirement for treatment.

NMDA receptor antagonists attenuate intrathecal morphine-induced pruritus through ERK phosphorylation

Pruritus is the most common complication of intrathecal morphine; however, its exact molecular mechanism is unclear, and treatment is challenging. The analgesic effect of N-methyl-D-aspartate (NMDA) receptor antagonists and the morphine-associated increase in NMDA receptor activation suggest potential role of NMDA receptor in the spinal itch sensation. Male C57BL/6 mice were given intrathecal morphine to induce scratching behavior. The effects of NMDA, ketamine, ifenprodil and U0126 on morphine-induced pruritus and analgesia were evaluated also. The number of scratching responses was counted for 30 min post-injection to evaluate pruritus. A warm-water tail immersion assay was conducted before and until 120 min post-injection at 30-min intervals. Percent of maximal possible effect (%MPE) and area under curve (AUC) were calculated based on tail-flick latency to evaluate analgesic efficacy. Compared with control treatment, intrathecal morphine elicited an obvious scratching response and analgesic effect in a dose dependent manner. Ketamine (1 μg), ifenprodil (0.1 μg) and U0126 (0.1 μg and 1.0 μg) all significantly attenuated morphine induced scratches. Ifenprodil (0.1 μg) injection significantly prolonged the analgesic effect of intrathecal morphine. The ERK1/2 phosphorylation induced by intrathecal morphine was inhibited by ketamine, ifenprodil and U0126 as well. U0126 inhibited morphine-induced pruritus with no effect on its analgesia. Therefore, intrathecal coadministration of morphine with NMDA receptor antagonists ketamine and ifenprodil alleviated morphine-induced scratching. Intrathecal morphine increased ERK phosphorylation in the lumbar spinal dorsal horn, which may be related with morphine-induced pruritus, and was counteracted by NMDA receptor antagonists.

Pruritus after intrathecal morphine for cesarean delivery: incidence, severity and its relation to serum serotonin level

BackgroundPruritus is the most common side effect of intrathecal morphine, especially in parturients. The exact mechanism is not clear and many possible mechanisms have been suggested. Among these is the activation of the 5-hydroxytryptamine sub-type-3 receptors by intrathecal morphine. MethodsForty parturients who underwent elective cesarean delivery under spinal anesthesia were divided into two groups of 20 each in this prospective, randomized study. Both groups received an intrathecal injection of 0.5% (2–3 mL) hyperbaric bupivacaine in addition to 100 μg of morphine in group 1 (M100) and 200 μg of morphine in group 2 (M200). Two blood samples were taken from each patient for serotonin estimation, preoperatively and four hours later. Postoperatively, all patients were assessed for pruritus (incidence and severity), pain (visual analog pain scale), first request for analgesia, and total analgesic dose required within 24 hours. ResultsThe serum serotonin level increased significantly postoperatively, by 283% versus 556% (P <0.05) in group M100 and M200, respectively. The incidence of pruritus was 55% in the M100 group, and 75% in the M200 group (P=0.32). Postoperative pruritus severity was significantly higher in group M200 than in group M100 (P <0.05) at six and eight hours; but not at other times. Postoperative analgesia, as well as analgesic consumption, was comparable between groups. ConclusionThe serum serotonin level increased significantly in the postoperative period in both groups, suggesting a role of serotonin in the genesis of intrathecal morphine-induced pruritus.

Prevalence and management of intrathecal morphine-induced pruritus in New Zealand Māori healthcare recipients.

The aim of this article was to determine whether the incidence of intrathecal morphine-induced pruritus (ITMI) was influenced by ethnicity, age or gender in relation to orthopaedic versus caesarean surgeries. The use of intrathecal morphine for patients undergoing total hip and knee joint replacements and for lower segment caesarean sections (LSCS) has gained popularity worldwide since its introduction over 30 years ago. Several international studies show that morphine delivered via the intrathecal route is an effective and safe method of pain relief. However, while the beneficial effects of intrathecal morphine have been clearly documented in many studies, so also have the adverse effects, predominantly being nausea and vomiting, pruritus and respiratory depression. Pruritus is described as one of the most common adverse effects, with a reported incidence of 30-100%. A retrospective study was conducted using data collected over a 21-month period on post-operative patients who had received intrathecal morphine as their post-operative pain management. A two-phased approach was undertaken. The study was conducted to determine the incidence of ITMI pruritus among two patient groups, New Zealand Māori and New Zealand European, 96 subjects in total, and if treatment was received. The findings revealed significant ethnic disparities whereas New Zealand Māori had a significantly higher rate of ITMI pruritus than New Zealand European, New Zealand Māori experienced the pruritus with more intensity and are less likely to be treated for it. Increased international knowledge and awareness for health professionals around the diversities of ethnicity and associated pharmacogenetics playing a significant role in patient response to opioid therapy can lead to improved overall care and patient satisfaction.

Ondansetron for neuraxial morphine-induced pruritus: A meta-analysis of randomized controlled trials.

Pruritus is one of the most common adverse effects associated with neuraxial morphine. Ondansetron has been used to deal with the problem of neuraxial morphine-induced pruritus (NMIP). The aim of this meta-analysis was to evaluate the preventive efficacy of ondansetron on NMIP. Online databases such as PubMed, EMBASE and the Cochrane Central Register of Controlled Trials were searched for eligible randomized controlled trials (RCTs). The primary outcome was the incidence of NMIP. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data. Trial sequential analysis (TSA) was performed to avoid the risk of making a spurious claim of significant effect and to calculate the sample size necessary to make a robust claim of effect. Our traditional meta-analysis showed that prophylactic ondansetron could significantly reduce the incidence of NMIP in non-obstetric patients (three trials, RR=0.63, 95% CI 0.45-0.89, P=.008) with modest heterogeneity (I2 =47%) while it did not show the preventive efficacy of NMIP in obstetric patients (seven trials, RR=0.84, 95% CI 0.69-1.03, P=.10) with obvious heterogeneity (I2 =82% ). However, TSA demonstrates that more high-quality RCTs are still needed to confirm the preventive efficacy of ondansetron on NMIP in non-obstetric populations and to study whether ondansetron prevents NMIP in obstetric patients. Prophylactic ondansetron can significantly reduce the incidence of NMIP in non-obstetric patients but not in obstetric patients. However, more well-designed trials are still required to test the reliability of the results in our traditional meta-analysis.

Abstract PR389

Background & Objectives: Intrathecal morphine provides effective, long lasting postoperative analgesia following Caesarean delivery, but is associated with pruritus which may be unpleasant. This prospective, double-blind controlled study compared sub-hypnotic doses of propofol as prophylaxis for intrathecal morphine-induced pruritus. Materials & Methods: Fifty-three ASA I & II parturients scheduled for elective Caesarean delivery were randomized to receive propofol 20 mg (Group A), propofol 10 mg (Group B) and normal saline (Group C). All parturients received 2 ml of 0.5% hyperbaric bupivacaine, fentanyl 25 μg and morphine 0.15 mg intrathecally. The study drugs were given over 30 seconds after delivery of the newborn. Pruritus was assessed using Verbal Rating Scale and recorded during recovery and at 4, 8 and 12 hours following intrathecal morphine. The level of sedation and post-operative nausea vomiting (PONV) were also recorded. Results: Demographic data of the parturients in all three groups were comparable. The cumulative incidences of pruritus were identical in Group A and Group B, 29.4% (95% CI: 7.8-51.1%), and comparable to Group C, 52.7% (95% CI: 30.2-75.1%), (p = 0.25). The NNT for moderate pruritus were less in Group A, 3.23 (95% CI: 2.99-3.47) than Group B, 3.98 (95% CI: 3.71-4.25). The incidence of moderate pruritus was significantly lower in Group A than Group C only at 4 hours (p < 0.05). PONV was significantly lower in Group A compared to Group C (p = 0.002) but similar between Groups A and B (p = 0.106) as well as Groups B and C (p = 0.095). Significantly more parturients in Groups A and B than Group C were sedated (p = 0.04). Conclusion: This study concluded that propofol was not effective in reducing the incidence of intrathecal morphine-induced pruritus in Caesarean delivery. However, its severity was reduced by propofol 20 mg at 4 hours post-delivery but not by propofol 10 mg.

Methylnaltrexone to Prevent Intrathecal Morphine-induced Pruritus After Cesarean Delivery

Methylnaltrexone to Prevent Intrathecal Morphine-induced Pruritus After Cesarean Delivery

Methylnaltrexone to Prevent Intrathecal Morphine-Induced Pruritus After Caesarean Delivery

Methylnaltrexone to Prevent Intrathecal Morphine-Induced Pruritus After Caesarean Delivery

Comparison of mirtazapine, gabapentin and ondansetron to prevent intrathecal morphine-induced pruritus.

OBJECTIVE:Antagonism of the central nervous system inhibitor neurotransmitter gamma-Aminobutyric acid (GABA) or serotonergic system activation is an important factor in the pathogenesis of intrathecal morphine-induced pruritus. This study tested the hypothesis that preoperative use of ondansetron, gabapentin or mirtazapine can prevent morphine-induced pruritus.METHODS:We randomly allocated 80 patients of American Society of Anesthesiology (ASA) classification I and II physical status who were to undergo unilateral inguinal hernia or pilonidal sinus operations under spinal anesthesia into 4 equal groups. The first 3 groups received oral doses of 30 mg mirtazapine, 8 mg ondansetron, and 1200 mg gabapentin at 2 hours, 10 minutes, and 1 hour before surgery, respectively, and the fourth group was given a placebo. All patients received intrathecal injection of 15 mg of 0.5% hyperbaric bupivacaine and 0.2 mg morphine. Pruritus was evaluated at 0, 3, 6, 9, 12, and 24 hours after intrathecal morphine administration, and details of presence, onset time, duration, localization, and severity of pruritus were recorded.RESULTS:Incidence of pruritus was significantly more frequent in the placebo group compared to ondansetron, gabapentin, and mirtazapine groups (70%, 55%, 35%, and 35%, respectively). In general, onset of pruritus was between 2 and 6 hours after intrathecal morphine injection; however, onset in the gabapentin group (mean±SD: 4.75±2.7 hours; p=0.019) was delayed compared to other groups. It was observed that pruritus persisted relatively longer in the ondansetron and placebo groups (mean±SD: 6±3.08; 5.82±2.96 hours, respectively; p=0.047). No statistical determination was made regarding location of pruritus. Severity of pruritus was greater in the placebo group (p=0.0001). Necessity for antipruritic treatment was not statistically significantly different between groups.CONCLUSION:Incidence and severity of intrathecal morphine-induced pruritus decreased with use of each of all 3 drugs compared to placebo.

Comparative study between nalbuphine and ondansetron in prevention of intrathecal morphine-induced pruritus in women undergoing cesarean section.

Background:Intrathecal morphine provides effective postoperative analgesia, but their use is associated with numerous side effects, including pruritus, nausea, vomiting, urinary retention, and respiratory depression. Pruritus is the most common side effect with a reported incidence of 58–85%.Objectives:This prospective, randomized, and double-blinded study was performed for women scheduled for cesarean delivery using spinal anesthesia to compare nalbuphine and ondansetron in the prevention of intrathecal morphine-induced pruritus.Patients and Methods:Ninety women after spinal anesthesia with hyperbaric bupivacaine and intrathecal morphine patients randomly divided into three groups. Women in placebo group (P group) received 4 ml of normal saline intravenous (IV) injection, nalbuphine group (N group) received 4 ml of a 4 mg nalbuphine IV injection, and ondansetron 4 group (O group) received 4 ml of a 4 mg ondansetron IV injection, immediately after delivery of the baby. Studied women observed in postanesthesia care unit for 4 h. The primary outcome measures success of the treatment, defined as a pruritus score 1 (no pruritus) or 2 (mild pruritus - no treatment required) at 20 min after treatment.Results:Although, three was no significant difference between the three studied groups regarding; score 1 pruritus, while, score 2 pruritus (mild pruritus - no treatment requested) was significantly high in N and O groups compared to placebo group. Pruritus score 1 (no pruritus) plus pruritus score 2 were significantly high in N and O groups compared to placebo group (20 cases, 20 cases, 5 cases; respectively, P = 0.008). In addition; score 3 pruritus (moderate - treatment requested) was significantly less in N and O groups compared to placebo group.Conclusion:Nalbuphine and ondansetron were found to be more effective than placebo for prevention of intrathecal morphine-induced pruritus in women undergoing cesarean delivery and nalbuphine is preferred than ondansetron because it is not excreted in the breast milk.