A randomized, double-blind study to compare the efficacy and safety of nalbuphine nasal spray and injectable solution in patients after orthopaedic interventions and traumatological procedures.

AIMS: Our previous 3-period crossover study in healthy volunteers comparing the pharmacokinetics of nalbuphine nasal spray Apain with parenteral nalbuphine solution demonstrated high bioavailability of the nasal spray and close similarity of pharmacokinetic profiles after intranasal and intramuscular administration, especially within 30 min postdose. The aim of the present study was a noninferiority assessment of nalbuphine nasal spray vs. intramuscular injection for pain relief in postoperative patients. METHODS: Ninety orthopaedic and traumatology patients were enrolled in this double-blind, randomized study of the effectiveness and tolerance of a single 10.5 mg dose of nalbuphine nasal spray vs. 10 mg intramuscular injection. The summed pain intensity difference (SPID0-6) calculated using visual analogue scale scores was the primary study endpoint. RESULTS: Of 90 subjects enrolled, the per-protocol efficacy population comprised 79 patients; 6 patients in the reference group and 5 patients in the test group were excluded due to remedication. The mean values of study endpoints with 95% confidence interval were as follows in reference and test groups, respectively: SPID0-6 = 228.08 (205.73-250.43) vs. 248.73 9 (225.83-271.63), time to pain relief onset = 0.28 h (0.25-0.31) vs. 0.27 h (0.25-0.29), duration of analgesia = 5.55 h (5.17-5.93) vs. 5.51 h (5.10-5.92), area under the curve = 119.30 (91.17-147.43) vs. 99.81 (74.52-107.10). No statistically significant differences were revealed. CONCLUSION: Nalbuphine nasal spray Apain has been proven to be a safe, noninvasive alternative to intramuscular nalbuphine to relieve severe postoperative pain. Designed for self-administration and dose-adjusting, the noncontrolled opioid analgesic nalbuphine spray can be used for patient-controlled analgesia in out-of-hospital, field and home settings.

Optimal Post-Operative Nalbuphine Dose Regimen: A Randomized Controlled Trial in Patients with Laparoscopic Cholecystectomy.

Background and Objectives: Optimal opioid analgesia is an excellent analgesia that does not present unexpected adverse effects. Nalbuphine, acting on the opioid receptor as a partial mu antagonist and kappa agonist, is considered a suitable option for patients undergoing laparoscopic surgery. Therefore, we aim to investigate the appropriate dosage of nalbuphine for post-operative pain management in patients with laparoscopic cholecystectomy. Materials and Methods: Patients were randomly categorized into low, medium, and high nalbuphine groups. In each group, a patient control device for post-operative pain control was programed with a low (0.05 mg/kg), medium (0.10 mg/kg), or high (0.20 mg/kg) nalbuphine dose as a loading dose and each bolus dose with a lockout interval of 7 min and without background infusion. Primary and secondary outcomes included the post-operative pain scale and nalbuphine consumption, and episodes of post-operative opioid-related adverse events and satisfactory scores. Results: The low-dosage group presented a higher initial self-reported pain score in comparison to the other two groups for the two hours post-op (p = 0.039) but presented lower nalbuphine consumption than the other two groups for four hours post-op (p = 0.047). There was no significant difference in the analysis of the satisfactory score and adverse events. Conclusions: An appropriate administration of nalbuphine could be 0.1 to 0.2 mg/kg at the initial four hours; this formula could be modified to a lower dosage (0.05 mg/kg) in the post-operative management of laparoscopic cholecystectomy.

Comparative pharmacokinetics of nalbuphine nasal spray and solution for injection in healthy volunteers.

AIMS: Nalbuphine is a synthetic opioid with comparable analgesic activity to morphine but with a better safety profile. Nalbuphine is only available in injectable form due to low oral bioavailability. Nasal nalbuphine spray provides advantages in drug safety, avoids hepatic first-pass metabolism, is non-invasive and is convenient for patient-controlled analgesia by self-administration. This study aimed to evaluate the safety and pharmacokinetics (PK) of the newly developed nalbuphine nasal spray in comparison with a solution for injections. METHODS: Twenty-four healthy Caucasian volunteers were enrolled in this randomized, open-label, cross-over study. Subjects were administered one of the drugs: nasal spray 7.0 mg/dose, nalbuphine hydrochloride solution for injection 10 mg/dose intravenously (IV) or intramuscularly (IM). High-performance liquid chromatography-tandem mass spectrometry was used to determine nalbuphine concentrations. RESULTS: A comparison of PK profiles for IV, IM and intranasal (IN) routes of nalbuphine administration revealed a close similarity of absorption phases for nasal spray and IM injection. Differences between the mean Tmax and dose-adjusted Cmax values for nasal spray and IM injection were statistically insignificant. The median values of the elimination rate constants and the terminal elimination half-life following IV, IM and IN nalbuphine administration were similar. The mean absolute bioavailability of the nasal spray equalled 65.04%. CONCLUSIONS: The similarity of PK parameters of IM-injected nalbuphine solution and the nasal spray allows us to assume the latter is a feasible alternative to intramuscular nalbuphine injections appropriate for self-administration and field environments for managing moderate and severe pain of various aetiologies.

A population pharmacokinetic-pharmacodynamic model evaluating efficacy of nalbuphine extended-release in patients with prurigo nodularis.

AIMS: Population pharmacokinetic (PK) and pharmacokinetic-pharmacodynamic (PK-PD) models were used to describe the exposure-response (E-R) relationship between nalbuphine exposure and two widely used rating scales for itch: the Numerical Rating Scale for the subject's 'average'; itch experience (NRS-AV) and the Worst Itch (WI-NRS), with 24-h recall. Simulations based on the model E-R relationship were used to support dose selection for Phase 3 clinical trials and were evaluated with a target of reducing the 7-day average of the 24-h WI-NRS by at least 30% from baseline in most of the analysis population. METHODS: Data from two clinical trials (NCT02373215: 9 healthy subjects; NCT02174419: 62 subjects with PN), in patients with prurigo nodularis (PN) with moderate to severe itch who received treatment with either of two doses of nalbuphine extended release (ER) or placebo, were used for the analysis. A two-compartment PK model with serial zero and first-order oral absorption was used to describe drug exposure. A maximum effect ( E max ) model with a placebo effect was used to model the itch response endpoints (NRS-AV, WI-NRS). RESULTS: The PK-PD model predicted the exposure-related reduction in both NRS-AV and WI-NRS over time with approximately 63% and 27% of E max , respectively. Exposures associated with 80% of E max were achieved in about 78% of the patients at 162 mg, twice daily (BID), compared to 35% at 81 mg BID. CONCLUSION: Simulated dose response indicated that 108 and 162 mg BID doses result in the highest proportion of patients achieving at least a 30% reduction in NRS-AV and WI-NRS, respectively.

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: Treatment of prurigo nodularis (PN) is challenging and new treatment options are needed. OBJECTIVE: To evaluate the efficacy and safety of two oral doses of the kappa opioid agonist and mu opioid antagonist nalbuphine extended release (NAL-ER) tablets in a phase 2, multicentre, randomized, double-blind, placebo-controlled trial with an open-label, 50-week extension phase. METHODS: Subjects with moderate-to-severe PN were randomized to NAL-ER 81 mg (NAL-ER81) or 162 mg (NAL-ER162) tablets twice-daily or placebo for 8 weeks of stable dosing following a 2-week titration period. Subjects completing Week 10 with a Worst Itch Numerical Rating Scale (WI-NRS) score ≥5 at the time of rollover (or during the observation period) were eligible for open-label treatment. RESULTS: Of 63 randomized subjects, 62 were treated and comprised the modified intent-to-treat population (MITT), 50 completed 10 weeks of treatment. In the MITT analysis, 8 subjects (44.4%) treated with NAL-ER162 (P = 0.32) and 6 (27.3%) treated with NAL-ER81 (P = 0.78) achieved ≥30% reduction from baseline in 7-day WI-NRS at Week 10 (primary efficacy endpoint) vs. 8 (36.4%) in the placebo group. Itch reduction was significant among 8/12 (66.7%) subjects completing Week 10 treated with NAL-ER162 vs. placebo (8/20, 40.0%; P = 0.03). Additionally, 6 subjects (33.3%) treated with NAL-ER162 and 3 (13.6%) treated with NAL-ER81 achieved ≥50% reduction from baseline in 7-day WI-NRS at Week 10 (coprimary endpoint). Extended open-label treatment was associated with further improvements in itch reduction and favourable changes in PN lesion activity as assessed by Prurigo Activity Score. Adverse events occurred predominantly during dose titration and were of mild-to-moderate severity. The safety profile did not change with extended open-label treatment. CONCLUSION: In adult subjects with PN, oral treatment with NAL-ER 162 mg twice daily provided measurable anti-pruritic efficacy in subjects completing ≥10 weeks of treatment and was well tolerated (ClinicalTrials.gov: NCT02174419).

Effects of multimodal analgesia of flurbiprofen axetil, nalbuphine and patient controlled intravenous analgesia on inflammatory factor levels and stress response in patients after laparoscopic radical gynecological malignancy surgery.

To evaluate the efficacy of multimodal analgesia of flurbiprofen axetil, nalbuphine hydrochloride and patient controlled intravenous analgesia (PCIA) on inflammatory factor levels and stress response in patients after laparoscopic radical gynecological malignancy surgery. The data of 100 patients admitted to our hospital from May 2019 to May 2020 for laparoscopic radical gynecological malignancy surgery were retrospectively analyzed and they were assigned (1:1) to either an experimental group or a control group according to the alphabetical order of their initials. The experimental group was given preemptive analgesia with flurbiprofen axetil, postoperative analgesia with nalbuphine hydrochloride, and PCIA and the control group was given conventional analgesic measures. The pain scores at 1h, 6h, 12h, 24h and 48h postoperatively in the experimental group were remarkably lower than those in the control group (P<0.001). The experimental group showed significantly lower inflammatory factor levels, pain mediator levels and stress response indexes in the morning before surgery, 1d, and 2d after surgery than the control group (P<0.001). The multimodal analgesia of flurbiprofen axetil, nalbuphine hydrochloride and PCIA can effectively alleviate the stress response and inflammatory response in patients after radical gynecologic malignancy surgery and the patients' pain perception is reduced with a high safety profile.

Pharmacokinetic comparison of nalbuphine with single injection and patient-controlled analgesia mimic method in healthy Chinese volunteers.

WHAT IS KNOWN AND OBJECTIVE: Nalbuphine is a mu (µ) receptor partial antagonist/kappa (κ) receptor agonist analgesic and can be administered as a single injection or using patient-controlled analgesia (PCA) in the clinical setting. However, differences in the pharmacokinetics of the two administration methods are unclear. Here, a clinical trial was performed to compare the pharmacokinetic characteristics and superiority of nalbuphine with a single-injection or PCA-mimic method to provide a reference for the selection of an appropriate administration method. METHODS: Twenty healthy individuals were divided into two groups and injected with 10 mg nalbuphine intravenously using a single-injection or a PCA-mimic method (2 mg once for five times with a 30-min interval). Blood samples were collected, and safety was investigated. The liquid chromatography-tandem mass spectrometry was adopted to determine the concentration of nalbuphine in plasma. RESULTS AND DISCUSSION: The maximum concentration (Cmax ) and area under concentration-time curve (AUC0-t ) values of nalbuphine in the single-injection and PCA groups were as follows: Cmax , 81.3 ± 24.7 and 39.8 ± 6.4 ng/ml, respectively; moreover, AUC0-t , 110.3 ± 19.5 and 128.3 ± 23.0 h ng/ml, respectively. The effective analgesic concentration durations (EACDs) for the two administration methods were 1.39 ± 0.64 and 1.96 ± 0.91 h, respectively. Nalbuphine was well tolerated, and improvements were observed in the PCA group. WHAT IS NEW AND CONCLUSION: Compared with those in the single-injection group, the AUC0-t and EACDs in the PCA group were similar, whereas Cmax was decreased significantly. Therefore, the PCA method was more suitable for the clinical application of nalbuphine injection owing to the superiority of lower concentration fluctuation and the improved safety profile.

Nelarabine as salvage therapy and bridge to allogeneic stem cell transplant in 118 adult patients with relapsed/refractory T-cell acute lymphoblastic leukemia/lymphoma. A CAMPUS ALL study.

The outcome of relapsed or refractory (R/R) T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/T-LBL) in adults is poor, with less than 20% of patients surviving at 5 years. Nelarabine is the only drug specifically approved for R/R T-ALL/T-LBL, but the information to support its use is based on limited available data. The aim of this observational phase four study was to provide recent additional data on the efficacy and safety of nelarabine in adults with R/R T-ALL/T-LBL and to evaluate the feasibility and outcome of allogeneic hematopoietic stem cell transplant (SCT) after salvage with nelarabine therapy. The primary endpoints were overall response rate (ORR) and overall survival (OS). Additional endpoints were safety, SCT rate and post-SCT OS. Between May 2007 and November 2018, 118 patients received nelarabine salvage therapy at 27 Italian hematology sites. The median age was 37 years (range 18-74 years), 73% were male, 77 had a diagnosis of T-ALL and 41 of T-LBL, and 65/118 (55%) had received more than two lines of therapy. The median number of nelarabine cycles was two (range 1-4); 43/118 (36%) patients had complete remission (CR), 16 had partial remission (14%) and 59 (50%) were refractory, with an ORR of 50%. The probability of OS, from the first dose of nelarabine, was 37% at 1 year with a median survival of 8 months. The OS at 1 year was significantly better for the 47 patients (40%) who underwent SCT after nelarabine salvage therapy (58% vs 22%, log-rank P < .001). The probability of OS at 2 and 5 years from SCT was 46% and 38%, respectively. Seventy-five patients (64%) experienced one or more drug-related adverse events (AE). Grade III-IV neurologic toxicities were observed in 9/118 (8%) of cases and thrombocytopenia or/and neutropenia (grade III-IV) were reported in 41% and 43% of cases, respectively. In conclusion, this is one of the largest cohorts of adult patients with R/R T-ALL/T-LBL treated in real life with nelarabine. Taking into account the poor prognosis of this patient population, nelarabine represents an effective option with an ORR of 50% and a CR rate of 36%. In addition, 40% of cases following nelarabine salvage therapy could undergo SCT with an expected OS at 2 and 5 years of 46% and 38%, respectively. The safety profile of nelarabine was acceptable with only 8% of cases showing grade III-IV neurological AE.

Pain management after ambulatory surgery: a prospective, multicenter, randomized, double-blinded parallel controlled trial comparing nalbuphine and tramadol.

BACKGROUND: Postoperative pain in ambulatory surgery is a multifactorial issue affecting patient satisfaction, time of discharge, and rehospitalization. This study evaluated the efficacy and safety of nalbuphine for the treatment of postoperative pain after ambulatory surgery, relative to tramadol. METHODS: This multi-center, randomized, double blind, and controlled study was conducted at 10 centers. In accordance with the inclusion criteria, 492 ambulatory surgery patients were recruited. These patients had moderate to severe pain after ambulatory surgery, with a visual analogue scale (VAS) score > 3 cm. They were randomly divided into an experimental (n = 248) or control (n = 244) group and treated for analgesia with 0.2 mg/kg of nalbuphine or 2 mg/kg of tramadol, respectively. VAS scores, adverse events, and vital signs of the patients were recorded before administration (baseline; T1); and 30 min (T2), 2 h (T3), 4 h (T4), and 6 h (T5) after administration of analgesia. A decrease in pain intensity of more than 25% compared with the baseline was used as an indicator of analgesic efficacy. The experimental and control groups were compared with regard to this indicator of efficacy at each timepoint. RESULTS: The VAS scores of the experimental and control groups were statistically comparable at timepoints T1-T4. At T5, the VAS scores of the experimental group were significantly lower than that of the control. The pain intensity was significantly higher in the experimental group compared with the control at T2 and T3. Adverse events and vital signs were similar for the two groups at each timepoint. CONCLUSIONS: Nalbuphine can provide effective and safe pain relief in patients after ambulatory surgery. TRIAL REGISTRATION: The registration number is ChiCTR-IOR-16010032 , the date of registration was 2016-11-28.

Nalbuphine Reduces Opioid-Associated Urinary Retention in Pediatric Patients.

OBJECTIVES: To evaluate the effect of nalbuphine administration on urine output in critically ill children with opioid-associated urinary retention. DESIGN: Institutional review board approved, single center, retrospective medical chart review. SETTING: Large medical-surgical PICU within a free-standing, tertiary care children's hospital. PATIENTS: Patients admitted to the PICU between October 1, 2014, and February 29, 2016, who received IV nalbuphine after meeting criteria for opioid-associated oliguria (defined as urine output below 1 mL/kg/hr and received at least one dose of opioid therapy within the preceding 12 hr). INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Seventeen patients who received 21 doses of nalbuphine were analyzed. The median age and weight of patients were 6 years (interquartile range, 3-11.5 yr) and 18 kg (interquartile range, 12-35 kg), respectively. Two distinct dosing strategies became evident, specifically 0.05 mg/kg (n = 11 doses) and 0.1 mg/kg (n = 10 doses). Urine output increased significantly from baseline (median, 0 mL/kg/hr; interquartile range, 0-0.53 mL/kg/hr) to 6 hours post nalbuphine administration (median, 1.48 mL/kg/hr; interquartile range, 0-2 mL/kg/hr; p = 0.0002). Patients who received 0.1 mg/kg/dose had a greater urine output response compared with those who received 0.05 mg/kg/dose. Five patients (29%) had a catheter inserted into their bladder after administration of nalbuphine. Pain scores (grouped 6 hr before and after nalbuphine administration and single pain scores documented immediately before and after nalbuphine administration) were unchanged. CONCLUSIONS: Nalbuphine administration, at a dose of 0.1 mg/kg, improved urine output in a cohort of children with opioid-associated urinary retention. Pain control did not appear influenced by the provision of nalbuphine. Additional studies are needed to determine the influence of nalbuphine on urinary catheter insertion rates and catheter-associated urinary tract infections.

Prophylactic Nalbuphine to Prevent Neuraxial Opioid-Induced Pruritus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PURPOSE: Evaluate the efficacy of prophylactic nalbuphine in preventing neuraxial opioid-induced pruritus. DESIGN: Systematic review and meta-analysis. METHODS: Following the PRISMA statement, PubMed, CINAHL, Cochrane and EMBASE were searched for eligible studies. FINDINGS: A total of 17 trials consisting of 1,052 patients were evaluated. Compared to placebo, there is low quality of evidence that nalbuphine was effective in reducing the incidence of pruritus in all patient population (RR, 0.66; 95% CI, 0.52 to 0.83; P = .0004) and obstetrics (RR, 0.81; 95% CI, 0.67 to 0.98; P = .03). We also found moderate quality of evidence that nalbuphine lowered pruritus in non-obstetrics, the number of rescue pruritus therapy and severity of pruritus episodes. However, nalbuphine did not cause sedation and affect pain scores. CONCLUSIONS: Prophylactic nalbuphine decreased the incidence and severity of pruritus without adverse effects on sedation and analgesic effect of opioids.

Nalbuphine for postoperative pain treatment in children.

BACKGROUND: Several surveys over the past few years have demonstrated that postoperative pain in children is not treated appropriately. One pharmacological treatment option in a multimodal approach for postoperative pain treatment is the systemic administration of opioids. However, opioids are rarely used for postoperative pain treatment in children due to fear of adverse events. One long-standing opioid for systemic use is nalbuphine, a kappa-receptor agonist and µ-receptor antagonist. The efficacy of nalbuphine is believed to be similar to morphine. Increased dosing might result in a ceiling effect, and thus less analgesia than expected. In addition, there might be a lower risk for opioid-induced side effects (nausea, vomiting) and severe adverse events (respiratory depression) due to the antagonistic effect of the µ-receptor. Nalbuphine may be an useful opioid for postoperative use in children, but exact efficacy (e.g. compared to other commonly used opioids) has not been determined yet. OBJECTIVES: To assess the efficacy and adverse events of nalbuphine for acute postoperative pain treatment in children undergoing surgery. SEARCH METHODS: We systematically searched the following databases: The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 7), MEDLINE via Pubmed (January 1966 to July 2013) and EMBASE via Ovid (January 1947 to July 2013). We did not impose any restrictions regarding language or publication date. We checked all reference lists of retrieved articles for additional references. SELECTION CRITERIA: All randomised controlled trials (RCTs) investigating nalbuphine compared with placebo or other opioids were included. DATA COLLECTION AND ANALYSIS: Two review authors independently scanned the retrieved articles and made a decision regarding inclusion or exclusion of studies for this review. The same authors also performed the data extraction and the assessment of risk of bias. MAIN RESULTS: Ten RCTs including 658 patients were finally included in this systematic review. Five trials compared nalbuphine with placebo. Data from one out of five studies for the outcome moderate/severe pain following nalbuphine compared to placebo gave a risk ratio (RR) 1 hour postoperatively (postop) of 0.1 (95% confidence interval (CI) 0.01 to 0.71; low quality evidence) and a RR 2 hours postop of 0.14 (95% CI 0.02 to 1.06; low quality evidence). The estimated RR based on data from a single study indicated that nalbuphine reduced the requirement for analgesia two hours postop (RR 0.47; 95% CI 0.27 to 0.84; low quality evidence). Two included trials compared nalbuphine with morphine and showed a nonsignificant lower or comparable RR for moderate/severe pain at 1 hour postop (RR 0.84; 95% CI 0.12 to 5.74; low quality evidence), and 2 hours postop (RR 1.09; 95% CI 0.59 to 2.01; low quality evidence) for nalbuphine versus morphine. Four trials compared nalbuphine with tramadol for postoperative pain; data from one trial (per outcome) revealed a lower but nonsignificant RR for the need of additional rescue analgesics in children receiving nalbuphine (RR 2 hours postop 0.75; 95% CI 0.39 to 1.43; low quality evidence) (RR 12 hours postop 0.33; 95% CI 0.04 to 2.77; low quality evidence). One out of three trials comparing nalbuphine with pethidine demonstrated that the RR was not significantly lower following nalbuphine administration compared to pethidine (RR 2 hours postop 1.07; 95% CI 0.52 to 2.23; low quality evidence) (RR 24 hours postop 1.13; 95% CI 0.52 to 2.44; very low quality evidence). The most common adverse event was postoperative nausea and vomiting (PONV). Only one included trial reported that the RR for PONV in the postoperative care unit (PACU) was not significantly higher following nalbuphine compared to placebo (RR 1.00; 95% CI 0.16 to 6.42; low quality evidence) nor to morphine (RR 1.33; 95% CI 0.64 to 2.77; low quality evidence). AUTHORS' CONCLUSIONS: Because the overall quality of available evidence was low, this systematic review could not definitively show that the analgesic efficacy of nalbuphine is superior compared to placebo. Furthermore, due to the lack of significant results the comparison with other common opioids is also unclear. The same holds true for the evidence focusing on adverse events following nalbuphine compared to placebo or other opioid administration. The evidence is limited, because studies did not report conclusively all important postoperative pain outcomes (e.g. number of patients with the need for rescue analgesia, postoperative pain scores). Thus, a quantitative analysis was not possible for many major aspects (e.g. rescue analgesia, pain scores) and heterogeneity could not be further explored.

Efficacy and safety of nalbuphine for epidural labor analgesia at high altitude: An observational study.

Xining is located at the eastern edge of the Qinghai-Tibet Plateau, with an average altitude of >7000 feet (>2000 m). Nalbuphine is a kappa-opioid receptor agonist that can provide analgesia with fewer side effects than other opioid analgesics. This study aimed to evaluate pain control, side effects, and neonatal outcomes from combining nalbuphine with sufentanil and ropivacaine in 600 women during epidural anesthesia while giving birth at a high altitude in Xining, China. A total of 600 parturients receiving epidural labor analgesia were randomly divided into 2 groups, each group 300 parturients. The nalbuphine group received nalbuphine, sufentanil, and ropivacain, the control group only received sufentanil and ropivacain. The analgesic effect was evaluated through the Visual Analogue Scale scores. Neonatal outcomes were mainly evaluated through the Apgar Scores. Compared to the control group, the nalbuphine group showed lower Visual Analogue Scale scores at all time points after analgesia (P < .05). In comparison with the control group, parturients in the nalbuphine group showed lower incidence rates of fever at delivery, 24-hour postpartum bleeding, and pruritus (P < .05). However, between the 2 groups, there were no statistically significant differences in the remaining maternal and infant outcomes and neonatal outcomes (P > .05). Moreover, no adverse effects on neonatal outcomes were observed. The findings from this study support findings from previous studies that nalbuphine provided safe epidural analgesia without significant side effects for the mother and infant, and showed both safety and efficacy when used during labor at high altitude.

Nalbuphine-6-glucuronide is a potent analgesic with superior safety profiles by altering binding affinity and selectivity for mu-/kappa-opioid receptors.

Although nalbuphine, a semi-synthetic analgesic compound, is less potent than morphine in terms of alleviating severe pain, our recent findings have revealed that nalbuphine-6-glucuronide (N6G), one of the glucuronide metabolites of nalbuphine, promotes a significantly more robust analgesic effect than its parent drug. Nevertheless, despite these promising observations, the precise mechanisms underlying the analgesic effects of nalbuphine glucuronides have yet to be determined. In this study, we aim to elucidate the mechanisms associated with the analgesic effects of nalbuphine glucuronides. Pharmacokinetic and pharmacodynamic studies were conducted to investigate the relationship between the central and peripheral compartments of nalbuphine and its derivatives. The analgesic responses of these compounds were evaluated based on multiple behavioral tests involving thermal and mechanical stimuli. Radioligand binding assays were also performed to determine the binding affinity and selectivity of these compounds for different opioid receptors. The results of these tests consistently confirmed that the heightened analgesic effects of N6G are mediated through its enhanced binding affinity for both mu- and kappa-opioid receptors, even comparable to those of morphine. Notably, N6G exhibited fewer side effects and did not induce sudden death, thereby highlighting its superior safety profile. Additionally, pharmacokinetic studies indicated that N6G could cross the blood-brain barrier when administered peripherally, offering pain relief. Overall, N6G provides great analgesic efficacy and enhanced safety. These findings highlight the potential value of nalbuphine glucuronides, particularly N6G, as promising candidates for the development of novel analgesic drugs.

Intrathecal bupivacaine in comparison with a combination of nalbuphine and bupivacaine for subarachnoid block: a randomized prospective double-blind clinical study.

We performed this randomized, prospective double-blind study to evaluate the effects of 2 different doses of intrathecal nalbuphine (a synthetic opioid agonist-antagonist) on the onset, duration of action, side effects, and complication produced by intrathecal hyperbaric 0.5% bupivacaine in lower abdominal, urologic and lower limb surgeries. Seventy-five patients of ASA grades 1 and 2 of either sex in the age group of 20-60 years were randomly allocated to 1 of 3 groups. Group A (n = 25) received 2.5 mL of 0.5% hyperbaric bupivacaine + 1 mL sterile water intrathecally; group B (n = 25) received 2.5 mL of 0.5% hyperbaric bupivacaine + 1 mL (200 µg) nalbuphine intrathecally; group C (n = 25) received 2.5 mL of 0.5% hyperbaric bupivacaine + 1 mL (400 µg) nalbuphine intrathecally. The onsets of sensory and motor blockade, highest level of sensory blockade, 2 segment regression time of sensory blockade, duration of motor blockade and analgesia, visual analog scale score, hemodynamic and respiratory changes, side effects were recorded, tabulated, and analyzed. Onsets of sensory and motor blockade and duration of motor blockade were not affected. Two segment regression time of sensory blockade and duration of analgesia were maximally prolonged in group C (P < 0.05). The visual analog scale scores were in the following order: group A > group B > group C at 90, 120, and 150 minutes after induction (P < 0.05). Hemodynamic and respiratory complications were absent except in 2 patients in groups A and C each, and 1 patient in group B developed bradycardia (P > 0.05). One patient in group A had nausea and vomiting, 2 patients in each group developed shivering (P > 0.05). No other side effect or complication was observed. Nalbuphine hydrochloride (400 µg) significantly prolongs the duration of sensory blockade and postoperative analgesia without any side effect or complication when introduced intrathecally along with hyperbaric bupivacaine.

Pharmacokinetics and tolerability of intranasal or intravenous administration of nalbuphine in infants.

OBJECTIVES: Intranasal nalbuphine could be a safe, efficacious and non-invasive alternative to parenteral pain medication in infants. We aimed to assess pharmacokinetics (PK) and tolerability of intranasal and intravenous nalbuphine administration in infants. METHODS: Prospective open-label study including infants 1-3 months of age admitted to the emergency department, receiving nalbuphine for procedural pain management. Patients were alternately allocated to a single nalbuphine dose of 0.05 mg/kg intravenously or 0.1 mg/kg intranasally. Nalbuphine PK samples were collected 15, 30 and 120-180 min after dosing. Area under the concentration time curve (AUC0-Tlast) was calculated by non-compartmental analysis (NCA) and compared by Wilcoxon test. Neonatal Infant Pain Score was assessed during nalbuphine administration and the following interventions: venous access, urinary catheterisation, lumbar puncture. RESULTS: Out of 52 study subjects receiving nalbuphine, 31 were eligible for NCA (11 intravenous, 20 intranasal). Median AUC0-Tlast after 0.05 mg/kg intravenously was 8.7 (IQR: 8.0-18.6) µg×L/hour vs 7.6 (5.4-10.4) µg×L/hour after intranasal administration of 0.1 mg/kg (p=0.091). Maximum serum concentration (Cmax) was observed 30 min after intranasal administration (3.5-5.6 µg/L). During intravenous and intranasal nalbuphine administration, mild to no pain was recorded in 71% and 67% of study subjects, respectively. CONCLUSION: This is the first study investigating intranasal administration of nalbuphine in infants suggesting an intranasal bioavailability close to 50%. Non-invasive intranasal application was well tolerated. Additional studies are warranted to optimise dosing and timing of interventions as Cmax is delayed by half an hour after intranasal administration. TRIAL REGISTRATION NUMBER: NCT03059511.

Effectiveness and safety of prehospital analgesia including nalbuphine and paracetamol by paramedics: an observational study.

BACKGROUND: The aim of this study was to examine the effectiveness and safety of prehospital analgesia with nalbuphine and/or paracetamol by paramedics. METHODS: In this retrospective trial, following the implementation of a standard-operating-procedure for pain requiring treatment as defined as a score ≥4 on the 0-10 Numeric Rating Scale for pain, all emergency operations in the district of Gütersloh between January 1, 2020, and June 30, 2022, with analgesic administration by paramedics in patients ≥18 years were included in the study. Analgesic agents employed by the paramedics included nalbuphine and/or paracetamol, butylscopolamine for abdominal colic, and esketamine in case of failure of the other analgesics. The primary endpoint was the patients' rating of their pain on the Numeric Rating Scale at the end of the operation. Additional covariates included sex, cause of pain, analgesics used, Numeric Rating Scale at beginning and analgesic-associated complications (reduced level of consciousness, hypotension, desaturation, a- or bradypnea). RESULTS: A total of 1931 emergency operations (female: N.=1039 [53.8%]) with pain requiring treatment (non-traumatic cause: N.=1106 [57.3%]; initial Numeric Rating Scale: 8.0±1.4). Analgesics applied were nalbuphine + paracetamol (50.6%), paracetamol (38.7%), butylscopolamine (13.4%), nalbuphine (7.7%), and esketamine (4.9%). Mean pain reduction was 4.3±2.3 (nalbuphine + paracetamol: 5.0±2.1; nalbuphine: 4.7±2.3) and paracetamol: 3.3±2.2, respectively. Factors influencing a change in the Numeric Rating Scale were trauma (regression-coefficient: -0.308, 95% CI: -0.496 - -0.119, P=0.0014 vs. non-trauma; nalbuphine [yes vs. no]: regression-coefficient 0.684, 95% CI 0.0774-1.291, P=0.03; nalbuphine + paracetamol: regression-coefficient 0.763, 95% CI 0.227-1.299, P=0.005). At the end of the operation, 49.7% had a Numeric Rating Scale <4, 34.3% had a Numeric Rating Scale 4-5, and 16.0% had a Numeric Rating Scale ≥6. Factors influencing a Numeric Rating Scale <4 at end of use were trauma vs. non-trauma: odds ratio 0.788, 95% CI 0.649-0.957, P=0.02. The Numeric Rating Scale at beginning reported: odds ratios 0.754, 95% CI 0.700-0.812, P<0.0001. Analgesic-associated complications were not observed. CONCLUSIONS: Prehospital analgesia by paramedics with nalbuphine as monotherapy or in combination with paracetamol allows for sufficient analgesia without the occurrence of complications.

Nalbuphine reduces the incidence of emergence agitation in children undergoing Adenotonsillectomy: A prospective, randomized, double-blind, multicenter study.

OBJECTIVE: To evaluate the effect of nalbuphine on emergence agitation (EA) in children undergoing adenotonsillectomy. DESIGN: Multicenter, prospective, double-blind, randomized controlled trial. SETTING: The First People's Hospital of Foshan and three other participating institutions in China, from April 2020 to December 2021. PATIENTS: Eight hundred patients, 3-9 years of age, American Society of Anesthesiologists (ASA) classification I or II, undergoing elective adenotonsillectomy were included. INTERVENTIONS: Nalbuphine (0.1 mg/kg) or saline was administered intravenously. MEASUREMENTS: The incidence of EA; the pediatric anesthesia emergence delirium (PAED) scale; and the faces, legs, activity, cry, and consolability (FLACC) scales. Extubation time, duration of post-anesthesia care unit (PACU) stay, anesthesia nurses' and parents' satisfaction, and other side effects. MAIN RESULTS: The incidence of EA in the nalbuphine group was lower than that in the saline group 30 min after extubation (10.28% vs. 28.39%, P = 0.000). In addition, the FLACC scores in the nalbuphine group were lower than those in the saline group 30 min after extubation (P < 0.05). Furthermore, the proportion of moderate-to-severe pain cases (FLACC scores >3) was significantly lower in the nalbuphine group than in the saline group (33.58% vs. 60.05%, P = 0.000). Adjusting the imbalance of postoperative pain intensity, the risk of EA was still lower in the nalbuphine group at 0 min (OR, 0.39; 95% CI, 0.26-0.60; P = 0.000), (OR, odds ratio; CI, confidence interval), 10 min (OR, 0.39; 95% CI, 0.19-0.79; P = 0.01), and 20 min (OR, 0.27; 95% CI, 0.08-0.99; P = 0.046) than in the saline group. There were no significant differences in extubation time, duration of PACU stay, nausea and vomiting, or respiratory depression between the two groups (P > 0.05). CONCLUSION: Nalbuphine reduced the incidence of EA in children after adenotonsillectomy under general anesthesia, which may be involved in both analgesic and non-analgesic pathways.

Nalbuphine May Be Superior to Sufentanil in Relieving Postcesarean Uterine Contraction Pain in Multiparas: A Retrospective Cohort Study.

Purpose: Postcesarean pain remains a major complaint from puerperium women who have undergone cesarean section, especially uterine contraction induced visceral pain. The optimal opioid for pain relief after cesarean section (CS) is still unclear. The goal of this study was to compare the analgesic effect of Nalbuphine to Sufentanil in patients who underwent CS. Patients and Methods: In this single-center retrospective cohort study, we included patients who received Nalbuphine or Sufentanil Patient-Controlled Intravenous Analgesia (PCIA) after CS between 1 January 2018 and 30 November 2020. Data on a Visual Analog Scale (VAS) at uterine contraction, at rest, and at movement, analgesic consumption, and side effects were collected. We performed logistic regression to identify predictors of severe uterine contraction pain. Results: A total of 674 patients were identified in the unmatched cohort, and 612 patients in the matched one. Compared to the Sufentanil group, lower VAS-contraction was recorded in the Nalbuphine group in both the unmatched and matched cohorts, the mean difference (MD) on POD1 was 0.35 (95% CI: 0.17 to 0.54, p<0.001) and 0.28 (95% CI: 0.08 to 0.47, p<0.001), respectively, and the MD of POD2 was 0.12 (95% CI: 0.03 to 0.40, P=0.019) and 0.12 (95% CI: 0.03 to 0.41, P=0.026), respectively. On POD1 but not POD2, VAS-movement was lower in the Nalbuphine group as compared to the Sufentanil group. No difference was found between VAS-rest on POD1 and POD2 in both unmatched and matched cohorts. Less analgesic consumption, and side effects were recorded in the Nalbuphine group. Logistic regression indicated that multipara and analgesic consumption were risk factors for severe uterine contraction pain. In subgroup analysis, VAS-contraction was meaningfully reduced in the Nalbuphine group compared with the Sufentanil group in multipara patients, but not primiparas. Conclusion: Compared to Sufentanil, Nalbuphine may provide better analgesia on uterine contraction pain. The superior analgesia may only exhibit in multiparas.

Safety and Efficacy of Oral Nalbuphine on Postoperative Pain in Hemorrhoidectomy Patients: A Randomized, Double-blind, Placebo-controlled, Pivotal Trial.

OBJECTIVES: Severe postoperative pain requiring opioid treatment has been reported in 20% to 40% of hemorrhoidectomy patients. Compared with morphine, nalbuphine offers better hemodynamic stability, a lower risk of respiratory depression, and a lower potential for addiction. Nalbuphine was developed from the intravenous form into an oral form (PHN131) to alleviate moderate-to-severe pain. MATERIALS AND METHODS: A randomized, double-blind, placebo-controlled, multiple-dose, parallel-design trial was conducted to evaluate the safety and efficacy of PHN131 in patients undergoing hemorrhoidectomy. Eligible patients were randomly assigned to receive either PHN131 soft capsules containing nalbuphine hydrochloride 60 mg or placebo capsules. Intramuscular diclofenac was the rescue analgesic. Pain was measured by the area under the curve of mean Visual Analog Scale pain intensity scores. RESULTS: Visual Analog Scale results in patients receiving PHN131 were significantly lower than placebo group scores through 48 hours postoperatively (149.2±75.52 vs. 179.6±65.97; P =0.0301). According to Brief Pain Inventory Short-Form scores, the impact of pain on quality of life was significantly smaller for the PHN131 group than for the placebo group. Time to the first use of diclofenac postoperatively was significantly longer in the PHN131 group than in the placebo group. The cumulative dosage of diclofenac in the PHN131 group was only around half of that in the placebo group ( P <0.0001). Drug-related adverse events were mild-to-moderate and resolved by the treatment end. No drug-related severe adverse events were observed. DISCUSSION: Our findings demonstrate that PHN131 is effective and well-tolerated in the treatment of moderate-to-severe post hemorrhoidectomy pain and may provide another option for patients to control their pain.