A comparision of nalbuphine with morphine for analgesic effects and safety : meta-analysis of randomized controlled trials

The effect of nalbuphine on prevention of emergence delirium in children: a systematic review with meta-analysis

BACKGROUND

Emergence delirium remains a major postoperative concern for children undergoing surgery. Nalbuphine is a synthetic mixed agonist-antagonist opioid, which is believed to reduce the incidence of emergence delirium in children. The primary objective was to examine the effect of nalbuphine on emergence delirium in children undergoing surgery.

METHODS

Databases of MEDLINE, EMBASE, and CENTRAL were searched from their starting dates until April 2023. Randomized Clinical Trials (RCT) and observational studies comparing nalbuphine and control in children undergoing surgery were included.

RESULTS

Eight studies (n = 1466 patients) were eligible for inclusion of data analysis. Compared to the control, our pooled data showed that the nalbuphine group was associated with lower incidence of emergence delirium (RR = 0.38, 95% CI [0.30, 0.47], p < 0.001) and reduced postoperative pain scores (MD = -0.98, 95% CI [-1.92, -0.04], p = 0.04).

CONCLUSIONS

This review showed the administration of nalbuphine is associated with significant decrease in the incidence of emergence delirium and postoperative pain scores among children undergoing surgery. However, due to limited sample size, high degree of heterogeneity and low level of evidence, future adequately powered trials are warranted to explore the efficacy of nalbuphine on emergence delirium among the pediatric population.

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.

Ultrasound-guided pericapsular nerve block compared with IV opioids in hip injuries: A randomised controlled trial

STUDY OBJECTIVES

The study aimed to compare the analgesic effect of USG-guided PENG (Peri capsular nerve group) block with Intravenous Nalbuphine hydrochloride (IVN) in patients with hip fracture coming to the emergency department (ED). The purpose was also to monitor the adverse effects and rescue analgesic requirements in both treatment modalities.

METHODS

The study was an open-label randomised controlled trial (RCT) comparing PENG block versus IVN in treating patients with femoral head and neck fractures, as well as pubic rami fracture of the hip (HF). The participants in the PENG group received a USG-guided PENG block by injection of 25 ml of 0.25% bupivacaine, whereas the IVN group received 0.15 mg/kg of nalbuphine. An emergency physician with expertise in ultrasound-guided nerve blocks performed the PENG blocks. The primary outcome was to measure the improvement of the NRS (Numerical rating scale) score at 30 min in both static position (Patient-chosen position for the best comfort) and dynamic position (15-degree passive affected lower limb elevation). Secondary outcomes were to measure static and dynamic NRS pain scores at 2 h, 4 h, and 6 h after intervention in both groups. The requirement for rescue analgesia, adverse events and any block-related complications were also recorded.

RESULTS

A total of 60 patients with HF were included in the final analysis. The static and dynamic NRS score was significantly lower in the PENG group compared to the IVN group at 30 min, 2 h, 4 h, and 6 h post-intervention. In the PENG group, the static NRS score was improved by 5.73 ± 1.17, while In the IVN group, the static NRS score was just improved by 2.13 ± 0.97 at 30 min. In the same duration, the Dynamic NRS score in the PENG group was improved by 6.13 ± 1.38, while In the IVN group, it improved just by 2.43 ± 1.28. Rescue analgesia was required in 50.0% of patients in the IVN group but none in the PENG group. Further, no block-related complications or adverse events were observed in the patients of the PENG group.

CONCLUSION

The study provides evidence that the ultrasound-guided PENG block has a better analgesic effect and has fewer adverse events than IV opioids in patients with HF.

Pharmacokinetics of nalbuphine administered intravenously and subcutaneously in goats (Capra aegagrus hircus)

The purpose of this study was to evaluate the pharmacokinetics (PK) of intravenously (IV) and subcutaneously (SC) administered nalbuphine in domestic goats. Nalbuphine hydrochloride was administered at 0.8 mg/kg for both IV and SC routes in six goats with a minimum of 10-day washout period between sample collection phases. Eighteen plasma samples were collected over a 36-hour period, analyzed using reverse phase high-performance liquid chromatography (HPLC). Plasma data were analyzed using compartmental and noncompartmental approaches. Following IV nalbuphine administration, elimination half-life, area under the plasma concentration time curve from time 0 to infinity (AUC0 - ∞), concentration at time zero (C0), and total body clearance were 120.4 ± 39.1 (min-1 ± SD), 17311.01 ± 7227.32 (min·ng·mL-1 ± SD), 675.6 ± 337.13 (ng·mL-1 ± SD), and 44.5 ± 13.8 (mL·min-1·kg-1 ± SD), respectively. After SC nalbuphine administration, elimination half-life, area under the plasma concentration time curve from time 0 to infinity (AUC0 - ∞), and maximum plasma drug concentration were 129 ± 52.9 (min-1 ± SD), 20826.5 ± 14376.2 (min·ng·mL-1), and 368.03 ± 503.78 (ng·mL-1). Calculated bioavailability for the SC route was 138 ± 126 (% ± SD). Nalbuphine in goats is characterized by rapid elimination and high subcutaneous bioavailability and may be a safe analgesic opioid option in goats in the future.

Nalbuphine versus morphine: an adjuvant to spinal anesthesia for controlling pain after total knee arthroplasty: a propensity score-matched analysis

BACKGROUND

Nalbuphine, a synthetic k-agonist and µ-antagonist, provides efficient pain relief while reducing opioid-related adverse effects. This study aims to compare the efficacy of intrathecal nalbuphine (ITN) with intrathecal morphine (ITM) for post-TKA pain.

METHODS

A retrospective cohort analysis of 131 patients who underwent TKA with spinal anesthesia (SA), a single shot of adductor canal block, and periarticular injections was conducted. The patients were divided into 2 groups, Group N received 0.8 mg nalbuphine, and Group M received 0.2 mg morphine as an adjuvant to SA. Propensity-score matching was employed to compare the visual analog scales (VAS) of postoperative pain intensity, cumulative morphine use (CMU), maximum knee flexion angle, straight leg raise (SLR) ability, incidence of postoperative nausea and vomiting (PONV), and length of hospital stay (LHS).

RESULTS

The mean VAS of group M were significantly lower than group N at 6, 12, 18, and 24 h (P < 0.01). Group M had lower CMU than group N at 24 h (P < 0.01) and 48 h (P < 0.01), while there was no significant difference between groups in terms of knee flexion angle and SLR at any time point. Additionally, 29.3 and 57.9% of patients in group N and M experienced PONV, respectively (p = 0.04), and group N had significantly shorter LHS compared to group M (P < 0.001).

CONCLUSION

Although, intrathecal morphine (ITM) still provides better pain control particularly in the first 24 h, patients who received intrathecal nalbuphine (ITN) had significantly fewer incidence of PONV, and shorter LHS.

Effectiveness and safety of prehospital analgesia with nalbuphine and paracetamol versus morphine by paramedics - an observational study

BACKGROUND

Despite the development of various analgesic concepts, prehospital oligoanalgesia remains very common. The present work examines prehospital analgesia by paramedics using morphine vs. nalbuphine + paracetamol.

METHODS

Patients with out-of-hospital-analgesia performed by paramedics from the emergency medical services of the districts of Fulda (morphine) and Gütersloh (nalbuphine + paracetamol) were evaluated with regards to pain intensity at the beginning and the end of prehospital treatment using the Numeric-Rating-Scale for pain (NRS), sex, age, and complications. The primary endpoint was achievement of adequate analgesia, defined as NRS < 4 at hospital handover, depending on the analgesics administered (nalbuphine + paracetamol vs. morphine). Pain intensity before and after receiving analgesia using the NRS, sex, age and complications were also monitored.

RESULTS

A total of 1,808 patients who received out-of-hospital-analgesia were evaluated (nalbuphine + paracetamol: 1,635 (90.4%), NRS-initial: 8.0 ± 1.4, NRS-at-handover: 3.7 ± 2.0; morphine: 173(9.6%), NRS-initial: 8.5 ± 1.1, NRS-at-handover: 5.1 ± 2.0). Factors influencing the difference in NRS were: initial pain intensity on the NRS (regression coefficient (RK): 0.7276, 95%CI: 0.6602-0.7950, p < 0.001), therapy with morphine vs. nalbuphine + paracetamol (RK: -1.2594, 95%CI: -1.5770 - -0.9418, p < 0.001) and traumatic vs. non-traumatic causes of pain (RK: -0.2952, 95%CI: -0.4879 - -0.1024, p = 0.002). Therapy with morphine (n = 34 (19.6%)) compared to nalbuphine + paracetamol (n = 796 (48.7%)) (odds ratio (OR): 0.274, 95%CI: 0.185-0.405, p < 0.001) and the initial NRS score (OR:0.827, 95%CI: 0.771-0.887, p < 0.001) reduced the odds of having an NRS < 4 at hospital handover. Complications occurred with morphine in n = 10 (5.8%) and with nalbuphine + paracetamol in n = 35 (2.1%) cases. Risk factors for complications were analgesia with morphine (OR: 2.690, 95%CI: 1.287-5.621, p = 0.008), female sex (OR: 2.024, 95%CI: 1.040-3.937, p = 0.0379), as well as age (OR: 1.018, 95%CI: 1.003-1.034, p = 0.02).

CONCLUSIONS

Compared to morphine, prehospital analgesia with nalbuphine + paracetamol yields favourable effects in terms of analgesic effectiveness and a lower rate of complications and should therefore be considered in future recommendations for prehospital analgesia.

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.

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.

Nalbuphine: an underrecognized battlefield analgesic and its utilization in combat care and peripheral areas

Battlefield injuries result in acute and severe uncontrolled pain, which can be reduced with the early use of analgesia. Apart from pain, battlefield injuries may also cause significant morbidity and a prolonged period of absence from active duty. Traditionally available opioids are known to cause various undesirable side effects such as respiratory depression that may worsen the condition of an already injured combatant. Nalbuphine is an opioid agonist-antagonist and has been increasingly used for postoperative analgesia over the last decade. In India, it is the only opioid analgesic that does not come under the Controlled Substances Act at the time of this publication. In today's world, where nalbuphine is being recommended for acute pain worldwide, its use in the Indian combat scenario needs to be conceptualized at the medical officer level (primary caregiver). This conceptualization will be discussed in detail in this review article.

Novel Opioids in the Setting of Acute Postoperative Pain: A Narrative Review

Although traditional opioids such as morphine and oxycodone are commonly used in the management of acute postoperative pain, novel opioids may play a role as alternatives that provide potent pain relief while minimizing adverse effects. In this review, we discuss the mechanisms of action, findings from preclinical studies and clinical trials, and potential advantages of several novel opioids. The more established include oliceridine (biased ligand activity to activate analgesia and downregulate opioid-related adverse events), tapentadol (mu-opioid agonist and norepinephrine reuptake inhibitor), and cebranopadol (mu-opioid agonist with nociceptin opioid peptide activity)-all of which have demonstrated success in the clinical setting when compared to traditional opioids. On the other hand, dinalbuphine sebacate (DNS; semi-synthetic mu partial antagonist and kappa agonist), dual enkephalinase inhibitors (STR-324, PL37, and PL265), and endomorphin-1 analog (CYT-1010) have shown good efficacy in preclinical studies with future plans for clinical trials. Rather than relying solely on mu-opioid receptor agonism to relieve pain and risk opioid-related adverse events (ORAEs), novel opioids make use of alternative mechanisms of action to treat pain while maintaining a safer side-effect profile, such as lower incidence of nausea, vomiting, sedation, and respiratory depression as well as reduced abuse potential.

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.

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.

Analgesic Efficacy of Nalbuphine as an Adjuvant to Ropivacaine in Erector Spinae Plane Block for Percutaneous Nephrolithotomy: A Randomized, Double-Blinded, Clinical Trial

Background

Erector spinae plane block (ESPB) is an easy and safe method for postoperative analgesia. However its effect lasts only for several hours. This trial was to investigate the effectiveness of different doses of nalbuphine as an adjuvant to ropivacaine in ESPB for patients undergoing percutaneous nephrolithotomy (PCNL).

Methods

Patients scheduled for PCNL were randomized into three groups and received ultrasound-guided ESPB at T10 level for postoperative analgesia. Each subject received 28 mL of 100 mg ropivacaine solution mixed with 2 mL of normal saline (Group R), 2 mL of 10 mg nalbuphine (Group RNL), or 2 mL of 20 mg nalbuphine (Group RNH). Primary outcome was the time to first opioid demand. Secondary outcomes were morphine consumption, VAS scores within 24 h postoperatively, rescue analgesic requirements, and length of hospital stay.

Results

The median [interquartile range, IQR] time to first opioid demand was significantly longer in group RNH (8.70 [6.90,14.85] h) than that of group R and group RNL (2.90 [2.00,6.30] h and 5.80 [2.95,7.00] h, respectively). VAS scores (either resting or active) within 24 h postoperatively were comparable between the three groups, with the most significant differences especially at 4, 6, 8 h. Morphine consumption at 24 h postoperatively was significant for R group vs RNH group (median difference, 9; 95% confidence interval [CI], 1.57 to 16.43; p = 0.02).

Conclusions

Adding 20mg nalbuphine to ropivacaine in ESPB could significantly improve the effect of analgesia and prolong the duration of nerve blocks for PCNL.

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.

Comparison of Two Different Doses of Nalbuphine With Isobaric Ropivacaine in Patients Undergoing Lower Segment Cesarean Section Under Subarachnoid Block: A Randomized Controlled Trial

INTRODUCTION

Obstetric analgesia and anesthesia is a challenge in itself. It requires an understanding of the physiological changes during pregnancy and labor and the effect of anesthetic agents on the fetus and newborn. Because neuraxial techniques provide superior analgesia and materno-fetal benefits, their use have increased significantly over the past three decades or so. A combination of local anesthetics like ropivacaine with opioids like nalbuphine has been shown to have additive beneficial effects in subarachnoid block (SAB) in lower segment cesarean section (LSCS). However, the optimal dose combination of ropivacaine and nalbuphine to maximize their benefits and minimize side effects remains to be established. Our study has compared the clinical efficacy and safety of 0.75% isobaric ropivacaine (15 mg) with two different doses of nalbuphine (0.4 mg and 0.6 mg) when given intrathecally for LSCS in terms of quality of sensory and motor blocks, hemodynamic parameters, duration of effective analgesia, Apgar score in newborn, and associated side effects.

METHOD AND MATERIALS

In this prospective, randomized, double-blind study, a total of 69 parturients between the age of 20-45 years, belonging to American Society of Anesthesiologists (ASA) grade I and II, undergoing cesarean section under SAB were evaluated. Patients were randomly allocated into three groups of 23 each by using the draw-of-lots technique. The patient and the observer were kept blinded as to which dose of drug (intrathecal) was being given to the patient. Patients in Group A received 0.75% isobaric ropivacaine 15 mg (2 ml) + 0.3 ml normal saline; patients in Group B received 0.75% isobaric ropivacaine 15 mg (2 ml) + 0.4 mg of nalbuphine (0.2 ml) + 0.1 ml normal saline; patients in Group C received 0.75% isobaric ropivacaine 15 mg (2 ml) + 0.6 mg of nalbuphine (0.3 ml). The total volume of drug solution in all three groups was 2.3 ml.

RESULT

 We found that the time to onset of sensory block was shortest in Group A (5.87±1.290 minutes) followed by Group C (6.00±1.087 minutes) and Group B (6.17±1.696 minutes); time to two-segment regression of sensory block was longest in Group C (101.74±8.996 minutes) followed by Group B (85.87±15.348 minutes) and Group A (65.00±7.071 minutes); duration of effective analgesia was longest in Group C (206.09±18.766 minutes) followed by Group B (183.91±15.880 minutes) and Group A (121.74±11.833 minutes); and time from SAB to complete regression of motor block was longest in Group C (216.52±15.553 minutes) followed by Group B (203.48±20.138 minutes) and Group A (174.78±14.731 minutes). Side effects were comparable among all three groups.

CONCLUSION

The optimal dose combination in SAB for cesarean section was 15 mg of 0.75% isobaric ropivacaine + 0.6 mg nalbuphine, with minimal side effects.

Efficacy and Safety of Parenteral Injection of an Extended Release κ-receptor Opioid Sebacoyl Dinalbuphine Ester for Acute and Chronic Pain After Laparoscopic Bariatric Surgery: a Randomized, Placebo-Controlled, Double-Blind Trial

PURPOSE

μ-receptor opioids are associated with unwanted gastrointestinal side effects and respiratory depression. A long-acting non-μ-receptor parenteral opioid is not currently available for management of acute and chronic postsurgical pain (CPSP). This double-blind clinical trial tested an extended-release κ-receptor agonist, sebacoyl dinalbuphine ester (SDE, Naldebain®) for management of surgical pain after laparoscopic bariatric surgery.

MATERIALS AND METHODS

Patients were randomly assigned to receive a single intramuscular injection of SDE (150 mg, n = 30) or vehicle solution (n = 30) at > 12 h before surgery. All patients received standard perioperative multimodal analgesia (MMA). The primary endpoint was the pain intensity in the beginning 7 days after operation. The secondary endpoints were adverse reactions up to 7 days and incidence of CPSP at 3 months after surgery.

RESULTS

Compared with placebos, the area under curves of visual analog scale (VAS) for 0-48 h after operation were significantly reduced in SDE group (143.3 ± 65.4 and 105.9 ± 36.3, P = 0.025). There were significantly fewer patients in the SDE group who had moderate-to-severe pain (VAS ≥ 4) (16.7% vs 50%; P = 0.012) at postoperative 48 h. Pain intensities were similar between the two groups at 72 h and 7 days postoperatively. The incidence of CPSP at 3 months was not different. SDE did not increase drug-related systemic adverse events.

CONCLUSION

In addition to the standard perioperative MMA, a single-dose injection of long-acting κ-receptor agonist SDE provides significantly better pain management for 48 h following laparoscopic bariatric surgery. A long-acting κ-receptor agonist opioid could improve in-hospital pain management and potentiate early discharge after operation without increasing drug-related systemic complications.

Analgesic efficacy and safety of nalbuphine versus morphine for perioperative tumor ablation: a randomized, controlled, multicenter trial

Background

The study will compare the efficacy and safety of nalbuphine hydrochloride injection and morphine hydrochloride injection for perioperative analgesia in tumor ablation and the differences between the two groups regarding duration of surgery, average daily dose, patient satisfaction with analgesia, quality of life, and other indicators. Furthermore, it will evaluate the clinical application of nalbuphine and morphine for perioperative analgesia in ablation surgery and provides important reference and guidance for clinical practice.

Methods

This is a randomized controlled study. Patients who were diagnosed by clinicians and required tumor ablation are enrolled and randomized to the experimental groups. In the test group, nalbuphine 80 mg + 0.9% normal saline (72 ml) is set in the patient-controlled analgesia pump, which is connected 15 min before ablation under electrocardiogram monitoring and surgery is performed immediately. The doses are as follows: initial,: 0.15 ml/kg,; background:, 0.5 ml/h,; compression:, 2 ml,; and lockout time:, 15 min. If the numeric rating scale is ≥ 4 points, the drug is administered by compression. The control group receives similar treatment under similar conditions as the test group except morphine (80 mg) is administered instead of nalbuphine (80 mg). The primary endpoints are the effective rate of analgesia and the incidence of adverse reactions (nausea and vomiting, dizziness, itching, constipation, hypoxemia, and urinary retention); the secondary endpoints are pain intensity, satisfaction with analgesia, duration of surgery, postoperative hospital stay, average daily dose, uninterrupted completion rate of surgery without complaints of pain, quality of life assessment, and vital signs.

Discussion

This study, to the best of our knowledge, is the first randomized controlled trial of nalbuphine patient-controlled analgesia in ablation surgery.

Trial registration

U.S. Clinical Trials Network Registration No.: NCT05073744. Registered on 11 October, 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06825-5.

Comparison of Side Effects of Nalbuphine and Morphine in the Treatment of Pain in children with Cancer: A Prospective Study

Contemporary pain management regimens in children do not include the use of the middle step of the analgesic ladder, i.e., weak opioids. The aim of this study was to analyse the comparison of side effects and the therapeutic efficacy of morphine and nalbuphine in pain management in children with cancer. We conducted an observational, prospective study and analysed medical records of patients treated at the Clinic of Paediatric Haematology and Oncology of the University Hospital in Wroclaw (Poland), who developed mucositis during treatment. The efficacy and safety of both drugs were analysed, and the efficacy of pain relief and the incidence of adverse effects characteristic of opioid drugs were compared. The cases of 96 of children treated with opioid drugs nalbuphine or morphine were analysed. Nalbuphine therapy was accompanied by a statistically significantly lower incidence of side effects such as skin pruritus, constipation, and micturition disorders compared to morphine (p < 0.05). After the discontinuation of nalbuphine, signs of withdrawal syndrome were much less frequent than after morphine (p < 0.05). In Conclusion, nalbuphine used as a pain killer in children with oncological disorder is a safe drug. It provides stable analgesia in most children. Compared to morphine, the side effects typical of opioid use are less common, and the incidence decreases over time.

Effective Doses of Nalbuphine Combined with Propofol in Painless Hysteroscopy

Purpose

Nalbuphine is becoming a common analgesic used in hysteroscopic operations. The aim of this study was to identify the median effective dose (ED50) and 95% effective dose (ED95) of nalbuphine combined with propofol in painless hysteroscopy.

Patients and Methods

Twenty-five patients aged 18–60 years with an American Society of Anesthesiologists classification of I–II who were scheduled for painless hysteroscopy were recruited. The initial dose of nalbuphine was set at 0.15 mg/kg and varied by 0.01 mg/kg according to the Dixon sequential method. The ED50/ED95 of nalbuphine combined with propofol for hysteroscopy was calculated by the probit method.

Results

The ED50 of nalbuphine was 0.122 (95% confidence interval (CI) 0.092–0.137) mg/kg, and the ED95 of nalbuphine was 0.153 (95% CI 0.138–0.361) mg/kg.

Conclusion

The ED50/ED95 values of nalbuphine combined with propofol in painless hysteroscopy are 0.122 mg/kg and 0.153 mg/kg, respectively. Nalbuphine at 0.153 mg/kg combined with propofol is effective and safe for painless hysteroscopy.

Effect of Preventive Analgesia with Nalbuphine and Dexmedetomidine in Endoscopic Sinus Surgery

Background

The study was to assess the efficacy and safety of nalbuphine combined with dexmedetomidine for preventive analgesia in endoscopic sinus surgery.

Methods

110 patients with deviation of the nasal septum were randomized into the nalbuphine group (group N), dexmedetomidine combined with nalbuphine group (group DN), and saline group (group C). Fifteen minutes before the induction of anesthesia, patients in group N were injected nalbuphine 0.2 mg/kg intravenously; patients in group DN received intravenous infusion of dexmedetomidine 0.5 μg/kg and injection of nalbuphine 0.2 mg/kg; patients in group C received 0.9% saline. Mean arterial pressure (MAP), heart rate (HR), numerical rating scale (NRS) scores, quality of recovery-40 (QoR-40) scores, the need for remedial analgesia, the consumption of remifentanil and propofol, and the incidence of adverse reactions were recorded.

Results

MAP, HR, and NRS scores of the DN group were significantly lower and the QoR-40 scores were higher than those of groups N and C (P < 0.001). The need for remedial analgesia, the consumption of remifentanil and propofol, and the incidence of nausea in the DN group were the lowest among the three groups (P < 0.001).

Conclusion

Preventive analgesia with nalbuphine and dexmedetomidine in endoscopic sinus surgery can not only maintain hemodynamic stability but also reduce intraoperative anesthetic dosage, postoperative pain, and improve the quality of postoperative recovery without affecting the revival and extubation time.

N-Dealkylation of Amines

N-dealkylation, the removal of an N-alkyl group from an amine, is an important chemical transformation which provides routes for the synthesis of a wide range of pharmaceuticals, agrochemicals, bulk and fine chemicals. N-dealkylation of amines is also an important in vivo metabolic pathway in the metabolism of xenobiotics. Identification and synthesis of drug metabolites such as N-dealkylated metabolites are necessary throughout all phases of drug development studies. In this review, different approaches for the N-dealkylation of amines including chemical, catalytic, electrochemical, photochemical and enzymatic methods will be discussed.

Agonists Specific for κ-Opioid Receptor Induces Apoptosis of HCC Cells Through Enhanced Endoplasmic Reticulum Stress

Cancer pain is an important factor affecting life quality of patients especially in the advanced stage and relieving pain is one of fundamental strategies for cancer treatment. Opioids such as morphine are the most widely used in clinics. However, they have been reported to be associated with the occurrence and development of several types of cancer. Thus, search for an opioid that has analgesic effect and can retard cancer progress simultaneously is critical for cancer management. In this study, we first examined the expression of μ and κ (MOR and KOR) in cell lines and tumor tissues of hepatocellular carcinoma (HCC), a malignant tumor with high mortality, and then compared the effects of opioid receptors-specific agonists on malignant phenotypes of HCC cells in vitro and tumor growth in an HCC xenograft mouse model. KOR and MOR were found to be highly expressed in HCC cell lines and HCC tissues. The KOR-specific agonist U50488h, oxycodone (agonist for both KOR and MOR) and the MOR-specific agonist morphine inhibited HCC cell proliferation, while only U50488h and oxycodone suppressed colony formation and migration of HCC cells. U50488h and oxycodone, but not morphine, induced HCC apoptosis. Further detection of PERK, GRP78 and CHOP revealed that PERK signaling was upregulated by treatment with U50488h, while treatment with the PERK inhibitor GSK2656157 partially reversed the promotion of apoptosis and inhibition of cell proliferation by U50488h, indicating that endoplasmic reticulum stress is associated with its suppressing effect on HCC malignant phenotypes. Similar to the in vitro results, HCC growth was significantly reduced by administration of U50488h and oxycodone, but not by morphine, in the HCC xenograft mouse model. PERK and caspase-3 in the HCC tissues were up-regulated by U50488h treatment as detected by immunohistochemistry and western blotting. Taken together, our results revealed that activation of KOR by U50488h inhibited malignant phenotypes of HCC both in vitro and in vivo, while activation of MOR by morphine did not have such effect. Because of their dual roles in the relief of pain and in the suppression of malignant phenotypes, opioids such as U50488h that act on KOR should be considered as the first choice for HCC management.

Pain management of nalbuphine and sufentanil in patients admitted intensive care unit of different ages

Background

Pain relief for patients in the intensive care unit (ICU) can improve treatment outcomes and reduce the burden on doctors and nurses. This study aims to report the clinical analgesic and sedative effects of nalbuphine and sufentanil on ICU patients.

Methods

This study retrospectively analyzed the medical records of 87 critically ill patients who received nalbuphine or sufentanil infusion in the ICU, including demographic data, diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II, Critical Care Pain Observation Tool (CPOT), Richmond Agitation-Sedation Scale (RASS), systolic and diastolic blood pressure, heart rate and blood oxygen saturation (SpO2). The primary outcomes of this study were CPOT and RASS scores. The secondary outcomes were hemodynamic changes, including systolic blood pressure, diastolic blood pressure, heart rate, and SpO2. The adverse events recorded during pain management, such as hypoxemia, respiration depression and bradycardia, were also collected and analyzed.

Results

None of the patients in both groups experienced episode of hypoxemia, respiration depression and bradycardia. However, age-stratified analyses showed that nalbuphine has a better analgesic effect than sufentanil for patients aged ≤ 60 (P < 0.05). In contrast, sufentanil showed a better analgesic effect than nalbuphine for patients aged > 60 ( P < 0.05). Furthermore, nalbuphine has a significantly better sedative effect than sufentanil for patients aged ≤ 60 (P < 0.05).

Conclusion

ICU patients of different age groups may be suitable for different analgesics. For patients under the age of 60, nalbuphine has better analgesia and sedation than sufentanil, and does not cause respiratory depression and drastic hemodynamic changes.

The use of topical nalbuphine in different concentrations to control pain after photorefractive keratectomy

PURPOSE

This is a randomized controlled study aiming to evaluate the safety and efficacy of two different concentrations of topical nalbuphine hydrochloride, when used to relieve pain in the first days following photorefractive keratectomy (PRK).

METHODS

This is a prospective double blinded randomized clinical trial that included 189 patients who had PRK for correction of low and moderate refractive errors. Patients were randomly assigned to three groups according to the eye drops given to relieve pain in the first three postoperative days; the first group received topical nalbuphine with a concentration of 2 mg/ml (Group A = 64 patients), the second group received topical nalbuphine in a concentration of 1 mg/ml (Group B = 69 patients) and the third group received topical artificial tears only (Group C = 56 patients).The patients were asked to rate their pain daily using a numeric rating scale and to record the number of drops instillation times/day. The time needed for complete epithelial healing, best-corrected visual acuity (BCVA) and spherical equivalent after three months were recorded in each group.

RESULTS

In the first three days, there was a statistically significant difference in pain score among the three groups with lower values in the two topical nalbuphine groups when compared with the control group receiving artificial tears. Moreover, the higher concentration group showed significantly lower pain score and less number of drops used /day in comparison with the lower concentration group.There were no statistically significant differences in epithelial healing time, BCVA and spherical equivalent after three months among the three groups.

CONCLUSION

The use of topical nalbuphine is effective in relieving pain in the first few days following PRK and this pain relief is not associated with any compromise regarding epithelial healing nor refractive outcome. The pain control with 2 mg/ml concentration is significantly higher than that with 1 mg/ml concentration of nalbuphine. Trial registration numberISRCTN21394752 https://doi.org/10.1186/ISRCTN21394752 The trial is retrospectively registered in ISRCTN registry at March 08, 2021.

Analgesic Effects of Different κ-Receptor Agonists Used in Daytime Laparoscopic Cholecystectomy

Background

Comparing the effect of two different κ-receptor agonists, nalbuphine and oxycodone, and regular morphine in patients for prophylactic analgesia of acute pain after daytime laparoscopic cholecystectomy.

Methods

One hundred and twenty-four patients undergoing laparoscopic cholecystectomy were randomly allocated to receive nalbuphine (group N), oxycodone (group O), and morphine (group M). The three groups were all given intravenous injection (iv.) of 0.15 mg/kg injection before incision and 0.05 mg/kg injection at the end of pneumoperitoneum. The Visual Analogue Scale (VAS) scores (incision, visceral, and shoulder) and Ramsay sedation scores at 1, 2, 4, 8, 12, 16, 20, and 24 hours after surgery, the time of extubation, the incidence of postoperative adverse events, the satisfaction of pain treatment, and the duration of stay after surgery were all recorded.

Results

Compared with group M, the VAS scores of visceral pain at rest decreased in group N and group O at 1-8 h after surgery (P < 0.05). The VAS scores of visceral pain at movement in group N decreased longer than those in group O (P < 0.05). Compared with that of group M, the postoperative time in Ramsay sedation score of group O increased longer than that of group N (P < 0.05). Compared with group N, patients had worse sleep quality in group O, longer length of stay in group M, and lower satisfaction in both groups.

Conclusion

Compared with morphine, prophylactic use of the κ-receptor agonists, nalbuphine and oxycodone, during laparoscopic cholecystectomy can reduce postoperative visceral pain. Furthermore, the nalbuphine group had fewer adverse reactions, better analgesia, and better satisfaction.

ED50 of Propofol Combined with Nalbuphine on the Sedative Effect in Painless Hysteroscopy

INTRODUCTION

Nalbuphine has gradually become a commonly used clinical analgesic drug for painless hysteroscopy. The aim of our study was to identify the median effective dose (ED50) of propofol combined with nalbuphine for painless hysteroscopy.

METHODS

Sixty-one patients aged 18-60 years were recruited to undergo elective painless hysteroscopy. Patients were administered 0.1 μg/kg nalbuphine (group A) or 0.2 μg/kg nalbuphine (group B) intravenously 3 min before endoscopic placement. The Dixon sequential method was used with an initial intravenous propofol dose of 2 mg/kg, which varied by 0.5 mg per kilogram.

RESULTS

The ED50 of propofol was 1.729 mg/kg (95% confidence interval [CI] 1.526-1.856 mg/kg) in group A and 1.658 mg/kg (95% CI 1.359-1.799 mg/kg) in group B. The 95% effective dose (ED95) of propofol was 2.051 mg/kg (95% CI 1.899-3.331 mg/kg) in group A and 2.020 mg/kg (95% CI 1.849-3.832 mg/kg) in group B.

CONCLUSION

For safety and effective painless hysteroscopic, the ED50 values of propofol combined with nalbuphine were 1.729 mg/kg (0.1 mg/kg nalbuphine) and 1.658 mg/kg (0.2 mg/kg nalbuphine). The recommended dose of nalbuphine is therefore 0.1 mg/kg.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2100042342 ( http://www.chictr.org.cn/edit.aspx?pid=66342&htm=4 ; registration date 19 Jan 2021).

Preemptive Intravenous Nalbuphine for the Treatment of Post-Operative Visceral Pain: A Multicenter, Double-Blind, Placebo-Controlled, Randomized Clinical Trial

INTRODUCTION

Post-operative visceral pain is common in early postoperative period after laparoscopic surgery. As a kappa opioid receptor agonist, the antinociceptive effects of nalbuphine in visceral pain are consistent across a multitude of experimental conditions irrespective of species. We hypothesized that preemptive nalbuphine can decrease the visceral pain for patients with incisional infiltration of ropivacaine after laparoscopic cholecystectomy.

METHODS

In a multicenter, prospective, double-blind, placebo-controlled, randomized clinical trial, 2094 participants scheduled for laparoscopic cholecystectomy were randomly assigned to receive nalbuphine (Nal group, n = 1029) or placebo (Con group, n = 1027). The Nal group received intravenous nalbuphine 0.2 mg·kg-1 and the Con group received saline in a similar way. The primary endpoint was the effect of nalbuphine on post-operative visceral pain intensity scores within 24 h postoperatively. The total amount of analgesic as well as complications were recorded.

RESULTS

A total of 1934 participants were analyzed. Nalbuphine reduced the visceral pain both at rest (β = - 0.1189, 95% CI - 0.23 to - 0.01, P = 0.037) and movement (β = - 0.1076, 95% CI - 0.21 to - 0.01, P = 0.040) compared with placebo. Patients in the Nal group required less frequent supplemental analgesic administration during the first 24 h after surgery. There were fewer patients in the Nal group who experienced nausea and vomiting (PONV) (P = 0.008).

CONCLUSIONS

Preemptive nalbuphine administered at a dose of 0.2 mg·kg-1 was safe and effective at reducing the postoperative visceral pain and supplemental analgesic use in patients undergoing laparoscopic cholecystectomy.

TRIAL REGISTRATION

Chinese Clinical Trial Registry; ChiCTR1800014379.

Comparison of Analgesic Effects between Nalbuphine and Sufentanil in First-Trimester Surgical Abortion: A Randomized, Double-Blind, Controlled Trial

Introduction

Surgical abortion is one of the commonly conducted procedures worldwide. Nevertheless, pregnant women still complain of procedural and postoperative pain despite the use of advanced anesthesia. It is vital to women’s reproductive healthcare to improve postsurgical pain management to achieve the lowest level of pain.

Methods

This randomized, double-blind, parallel-controlled clinical trial compared the analgesic effects between nalbuphine and sufentanil in patients who underwent first-trimester surgical abortion. In total, 224 patients were allocated randomly into (a) the sufentanil group that received sufentanil (0.1 ug/kg) combined propofol, and (b) the nalbuphine group that received nalbuphine (0.1 mg/kg) combined propofol. Postoperative pain scores, propofol injection pain, intraoperative analgesic effect, adverse events, and degree of satisfaction were recorded as outcome measures.

Results

The pain scores in the nalbuphine group were lower than those in the sufentanil group at 15 min, 30 min, 1 h, and 6 h after surgical abortion. In addition, the incidence and intensity of propofol injection pain were lower in the nalbuphine group. The degree of satisfaction of the patients in the nalbuphine group was higher than that in the sufentanil group. The intraoperative analgesic effect, hemodynamic fluctuation, and adverse events were comparable between the two groups.

Conclusions

Nalbuphine combined with propofol is superior to sufentanil combined with propofol for first-trimester abortion surgeries.

Clinical Trial Registration

The trial was registered at www.chictr.org.cn, identifier ChiCTR2000040243.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-021-00334-0.

Influence of Catheter-Incision Congruency in Epidural Analgesia on Postcesarean Pain Management: A Single-Blinded Randomized Controlled Trial

Patient-controlled epidural analgesia (PCEA) or epidural morphine may alleviate postcesarean pain; however, conventional lumbar epidural insertion is catheter–incision incongruent for cesarean delivery. Methods: In total, 189 women who underwent cesarean delivery were randomly divided into four groups (low thoracic PCEA, lumbar PCEA, low thoracic morphine, and lumbar morphine groups) for postcesarean pain management. Pain intensities, including static pain, dynamic pain, and uterine cramp, were measured using a 100 mm visual analog scale (VAS). The proportion of participants who experienced dynamic wound pain with a VAS score of >33 mm was evaluated as the primary outcome. Adverse effects, including lower extremity blockade, pruritus, postoperative nausea and vomiting, sedation, and time of first passage of flatulence, were evaluated. Results: The low thoracic PCEA group had the lowest proportion of participants reporting dynamic pain at 6 h after spinal anesthesia (low thoracic PCEA, 28.8%; lumbar PCEA, 69.4%; low thoracic morphine, 67.3%; lumbar morphine group, 73.9%; p < 0.001). The aforementioned group also reported the most favorable VAS scores for static, dynamic, and uterine cramp pain during the first 24 h after surgery. Adverse effect profiles were similar among the four groups, but a higher proportion of participants in the lumbar PCEA group (approximately 20% more than in the other three groups) reported prolonged postoperative lower extremity motor blockade (p = 0.005). In addition, the first passage of flatulence after surgery reported by the low thoracic PCEA group was approximately 8 h earlier than that of the two morphine groups (p < 0.001). Conclusions: Epidural congruency is essential to PCEA for postcesarean pain. Low thoracic PCEA achieves favorable analgesic effects and may promote postoperative gastrointestinal recovery without additional adverse effects.

Different Doses of Nalbuphine Combined with Dexmedetomidine in Laparoscopic Oophorocystectomy

BACKGROUND The goal of this study was to investigate different doses of nalbuphine combined with dexmedetomidine in the postoperative treatment of laparoscopic oophorocystectomy. MATERIAL AND METHODS This prospective single-blinded randomized controlled study included 219 patients with benign ovarian cysts who received laparoscopic oophorocystectomy from March 2017 to October 2019. Patients were randomized into 4 groups: low (0.5 mg/kg), middle (1.0 mg/kg), and high (1.5 mg/kg) doses of nalbuphine combined with dexmedetomidine (4 μg/kg) (LND, MND, and HND groups, respectively) and a control group with sufentanil (2.5 μg/kg), with different patient-controlled intravenous analgesia pump (PCIA) strategies. Rest and active visual analog scale (VAS) scores measured postoperative pain, and Ramsay scores were used to measure sedation. RESULTS The HND group showed the lowest rest and cough VAS scores at 2 h, 8 h, 12 h, and 24 h after surgery, the lowest PCIA pressing time within 48 h after surgery, and the highest Ramsay scores at 2 h, 8 h, 24 h and 48 h after surgery. Rest and cough VAS scores decreased with higher nalbuphine doses in a dose-dependent manner. One day after surgery, IL-1ß and IL-6 levels increased in all groups, with the lowest levels of IL-1ß and IL-6 in the HND group. Hospitalization time was significantly shorter in the HND group compared with the LND and MND groups. There were no significant differences in complications among groups. CONCLUSIONS Combined nalbuphine and dexmedetomidine improved postoperative pain and sedative conditions, reduced inflammation in a nalbuphine dose-dependent manner, and might facilitate patient recovery.

The Effect of Epidural Nalbuphine Combined With Ropivacaine on Epidural Analgesia During Labor: A Multicenter, Randomized, Double-blind, Controlled Study

OBJECTIVES

The addition of a small dose of opioids during epidural labor analgesia can enhance the local analgesic effect, reduce the dose of local anaesthetic required, and minimize motor blockade. For the treatment of visceral pain, studies have shown that κ-opioid receptor agonist are more effective than μ-receptor agonists. This study compared the effectiveness of epidural nalbuphine and sufentanil in combination with ropivacaine for labor analgesia, respectively.

MATERIALS AND METHODS

We conducted a prospective, randomized, double-blind, multicentre clinical trial. Parturients who requested labor pain relief were randomly assigned to either the nalbuphine group or sufentanil group. After 5 minutes of initial dose, parturients in nalbuphine group received 10 mL 0.1% ropivacaine plus 0.3 mg/mL nalbuphine solution. The sufentanil group received the same ropivacaine dose plus 0.3 μg/mL sufentanil. The primary outcome was the duration of analgesia (the time to the first requirement for additional medication). Secondary outcomes included the ropivacaine dose per hour, and adverse reactions.

RESULTS

Between November 2018 and February 2019, 180 parturients were recruited for the study. The study showed that the duration of analgesia was shorter in the nalbuphine group as compared with the sufentanil group (P=0.040). The ropivacaine dose per hour in nalbuphine group 9.3 (2.4) mg was significantly greater versus sufentanil group 8.4 (2.5) mg (P=0.024). No serious adverse events directly associated with the analgesics were observed.

DISCUSSION

The analgesia effects of 0.3 mg/mL nalbuphine with ropivacaine are inferior to 0.3 μg/mL sufentanil with ropivacaine in labor analgesia. No serious side effects, either in the mother or in the fetus, were observed.

Nalbuphine: a candidate for treatment of women overwhelmed with sudden, intense labor pain?

AIM

On very rare occasions, women are overwhelmed with sudden, intense labor pain in the context of ultra-rapid late second stage of labor, especially when the head is crowning. The consequences may comprise serious pelvic floor damage for the mother and hypoxia for the fetus. Drugs like nalbuphine for immediate maternal analgesia and sedation would be helpful. This mixed opioid agonist-antagonist, that was used in obstetric anesthesia in the 1980s, acts quickly while side effects for the mother are minor. To better estimate possible complications for the fetus of a use shortly before birth, it is important to find out how quickly i.v. administered nalbuphine reaches fetal circulation. Therefore, we characterized the transplacental transfer of nalbuphine using an ex vivo model.

METHODS

Placentas were obtained from cesarean sections after mothers gave their informed consent. Upon cannulation of one cotyledon, nalbuphine was added to the maternal circuit (calculated final concentration 100 ng/mL) and the ex vivo placenta perfusions were performed. To determine nalbuphine transfer from maternal to fetal circuit in the successful perfusions (n = 5), samples were collected at different time points.

RESULTS

At perfusion start, the measured initial nalbuphine concentrations in the maternal and fetal circuits are 93.1 and <0.1 ng/mL, respectively. After 5 min of placenta perfusion, 2.5 ng/mL nalbuphine (i.e. 3% of the initial nalbuphine concentration in the maternal circuit) is reached in the fetal circuit; after 15 and 30 min, 9.7 and 15.8 ng/mL (approximately 10 and 16% of initial maternal, respectively).

CONCLUSIONS

Only a small amount of nalbuphine is likely to reach the fetus during the first minutes after (i.v.) maternal administration. Nalbuphine might be a valuable candidate for clinical use in the i.v. analgesia and sedation of women overwhelmed with sudden labor pain in the context of ultra-rapid second stage of labor.

Nalbuphine for spinal anesthesia: A systematic review and meta-analysis

PURPOSE

Various adjuvants for prolongation of intra-operative and postoperative analgesia have been clinically studied, but the safety and efficiency of nalbuphine as an adjuvant to local anesthetics in spinal anesthesia remains unconfirmed. Therefore, we conducted a meta-analysis about the effect of nalbuphine as an adjuvant to local anesthetics in spinal anesthesia in regard to time of onset of sensory blockade and motor blockade, duration of motor blockade, 2-segment sensory regression time, the duration of analgesia, and incidence of side effects to provide a reliable basis for clinical application.

METHODS

Databases, including PubMed, Cochrane, EMBASE, Web of Science, CNKI, CBM, WanFang, and Viper, were searched for eligible studies. Data were extracted according to the proposed inclusion and exclusion criteria, RevMan version 5.3 and Stata 16 were selected to perform meta-analysis.

RESULTS

Eighteen published studies including 1633 patients met the inclusion criteria. The results showed that adding nalbuphine to local anesthetics for spinal anesthesia can prolong two-segment sensory regression time (mean difference [MD] = 24.31; 95% confidence interval [CI] = 19.61-29.00, p < 0.001) and the duration of analgesia (MD = 118.11; 95% CI = 71.34-164.89, p < 0.001) without significantly increasing the incidence of adverse reactions in comparison to normal saline group. In addition, the analgesic effect of nalbuphine group was not statistically different from that of control group when compared with the potent opioid group, but the occurrence of hypotension (risk ratio [RR] = 0.35, 95% CI = 0.18-0.68, p < 0.01), the occurrence of shivering (RR = 0.19, 95% CI = 0.08-0.43, p < 0.01), and the occurrence of pruritus (RR = 0.23, 95% CI = 0.10-0.53, p < 0.01) was lower than the potent opioid group.

CONCLUSIONS

Nalbuphine as additives to local anesthetics can significantly prolong the two segments of sensory block and the average duration of analgesia without increasing the incidence of adverse reactions when compared with normal saline group. In addition, the analgesic efficacy of nalbuphine served as an adjunct to local anesthetics was clinically not different from that of the potent opioids, but the occurrence of hypotension, shivering, and pruritus was lower than the potent opioids.

Application of Nalbuphine in Trigeminal Ganglion Pulse Radiofrequency Surgery in Patients with Postherpetic Neuralgia

This study aimed to explore the application value of nalbuphine in pulsed radiofrequency operation of trigeminal ganglion in patients with postherpetic neuralgia (PHN). Thirty patients with PHN were randomly divided into the nalbuphine (Nalbu) group and ketorolac tromethamine (KT) group and received CT-guided pulsed radiofrequency surgery on trigeminal ganglion. The numeric rating scale (NRS) scores of patients were recorded at preoperative, intraoperative, and postoperative time points, before going to bed, and the next morning after the operation. In addition, the number of breakthrough pain before operation and within 24 hours after operation, the incidence of nausea and vomiting within 24 hours after surgery, and the patient's sleep quality before and on the day after surgery were evaluated. The outcome data demonstrated that patients treated with nalbuphine had lower NRS scores after the pulse radiofrequency operation during and after the pulse radiofrequency operation compared to those with KT. In addition, nalbuphine effectively decreased the number of breakthrough pain, reduced the occurrence of nausea and vomiting after surgery, and improved the sleep quality. In conclusion, intramuscular injection of nalbuphine 30 min before trigeminal ganglion pulse radiofrequency surgery can be conducive to pain relief and improve the postoperative comfort of patients, providing an effective alternative for the alleviation of PHN in clinic.

[Analgesia for trauma patients in emergency medicine]

Adequate analgesia is one of the most important measures of emergency care in addition to treatment of vital function disorders and, if indicated, should be promptly undertaken; however, a large proportion of emergency patients receive no or only inadequate pain therapy. The numeric rating scale (NRS) is recommended for pain assessment but is not applicable to every group of patients; therefore, vital signs and body language should be included in the assessment. Pain therapy should reduce the NPRS to <5 points. Ketamine and fentanyl, which have an especially rapid onset of action, and also morphine are suitable for analgesia in spontaneously breathing patients. Basic prerequisites for safe and effective analgesia by healthcare professionals are the use of adequate monitoring, the provision of well-defined emergency equipment, and the mastery of emergency procedures. In a structured competence system, paramedics and nursing personnel can perform safe and effective analgesia.

Nalbuphine on postoperative gastrointestinal tract dysfunction after laparoscopic surgery for gynaecological malignancies: A randomized controlled trial

The aim of this study was to compare the effects of nalbuphine and sufentanil on the gastrointestinal (GI) tract after laparoscopic surgery for gynaecological malignancies. A total of 100 patients with American Society of Anesthesiologists (ASA) physical status I-II undergoing laparoscopic radical hysterectomy under general anaesthesia were enrolled. The patients were randomized to receive sufentanil (Group S) or nalbuphine (Group N) intraoperatively and postoperatively. The time to first passage of flatus, the time to first defaecation, the time to toleration of diet, the serum gastrin level, and the duration of hospital stay of the groups were compared. The Visual Analogue Scale (VAS) score for postoperative pain, the number of dispensed patient-controlled analgaesics (PCAs), and the prevalence of postoperative nausea, vomiting, and dizziness of the groups were also compared. The time to first passage of flatus (P = .551), time to first defaecation (P = .310), time to toleration of diet (P = .182), serum gastrin level (P = .397), prevalence of postoperative nausea (P = .920) and vomiting (P = .334), number of dispensed PCAs (P = .167), and the duration of hospital stay (P = .482) of the two groups were not significantly different. The VAS scores at 6 hours (P = .008), 12 hours (P = .002), and 24 hours (P = .013) postoperatively were lower in Group N than in Group S. In conclusion, nalbuphine was not associated with improved postoperative GI dysfunction after laparoscopic surgery for gynaecological malignancies, but it was associated with reduced postoperative pain.

Intra-arterial anaesthetics for pain control in arterial embolisation procedures: a systematic review and meta-analysis

Purpose

A systematic review to determine the effectiveness of intra-arterial anaesthetics on post- operative pain and opioid analgesia requirements in arterial embolisation procedures.

Materials and methods

A systematic review of the literature was performed (Embase, PubMed, MEDLINE and the Cochrane Library) from inception to 10th August 2020. Randomised controlled trials (RCTs) and cohort studies that utilised intra-arterial anaesthesia during an embolisation procedure for the purposes of pain control were included. Eligibility was assessed by two investigators independently.

Results

Eight hundred fifty-nine candidate articles were identified, and 9 studies met the inclusion criteria (6 RCTs and 3 retrospective cohort studies). Four studies were of hepatic chemoembolisation and 5 were of uterine artery embolisation.

Five hundred twenty-nine patients were treated in total. All studies used lidocaine as the anaesthetic with doses ranging from 20 to 200 mg, and the anaesthetic was delivered varyingly before, during or after embolisation. Pain intensity was converted to a numeric scale from 0 to 10, and opioid doses were converted to milligram morphine equivalent doses. A random-effects meta-analysis model was used to analyse the results of RCTs, and the results of cohort studies were summarised with a narrative synthesis. The meta-analyses suggested that pain scores were reduced by a mean of 1.02 (95% CI − 2.34 to 0.30; p = 0.13) and opioid doses were reduced by a mean of 7.35 mg (95% CI, − 14.77, 0.06; p = 0.05) in the intervention group however neither finding was statistically significant. No serious adverse events were reported.

Conclusion

Intra-arterial anaesthetic may slightly reduce pain intensity and post-operative opioid consumption following embolisation, however the results are not statistically significant. There is very limited data available on the effect of anaesthetic on length of hospital admission. Whilst no serious adverse events were reported, there are some concerns regarding the effect of lidocaine on the technical success of embolisation procedures that preclude our recommendation for routine use in embolisation procedures.

High quality randomised controlled trials are required to elucidate the dose-response effect of lidocaine on opioid consumption and pain following embolisation, particularly in the first few hours post-operatively, as well as effects on duration of hospital stay.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42155-020-00198-z.

Comparison of Postoperative Analgesic Effects Between Nalbuphine and Fentanyl in Children Undergoing Adenotonsillectomy: A Prospective, Randomized, Double-Blind, Multicenter Study

Objective: There is no universal agreement on optimal pharmacological regimens for pain management during surgeries. The aim of this study to compare the postoperative analgesic effects of nalbuphine with fentanyl in children undergoing adenotonsillectomy.

Design, Setting, Participants: We conducted a prospective, randomized, double-blind, non-inferiority and multicenter trial in 311 patients admitted to four different medical facilities in China from October 2017 to November 2018.

Main Outcome Measure: The primary outcome was postoperative pain score. The secondary outcomes were as follows: the numbers of patients who developed moderate or severe pain (FLACC ≥4 points); time to first rescue analgesic top up and the actual number of rescue pain medicine given in pain control in post-anesthesia care unit (PACU), and additional analgesics requirement (received ≥2 rescue analgesics or/and other analgesics except study medications administered in PACU and ward); emergence and extubation time; Waking up time; time of PACU stay, and other side effects (desaturation, nausea/vomiting etc.).

Results: A total of 356 children were screened and 322 patients were randomized. The mean age was 5.8 (5.5, 6.1) in the nalbuphine group and 5.6 (5.3, 5.8) in the fentanyl group (p = 0.2132). FLACC score of nalbuphine group was lower than that of fentanyl group upon patients' arrival at PACU (p < 0.05). The time to first required rescue dose of pain drug for nalbuphine group was longer than for the fentanyl group (2.5 vs 1.2 h, p < 0.0001). Only one patient (0.6%) in nalbuphine group presented a slow respiratory rate (RR) at 9/min while 29 patients (18.5%) in fentanyl group developed slow RR ≤10/min in PACU. Meanwhile, SpO₂ was lower in the fentanyl group at 10 min after patients’ arrival in PACU (p < 0.05). The other profiles observed from these two drug groups were similar.

Conclusion: Nalbuphine provided better pain relief with minimal respiration depression than fentanyl in children undergoing Adenotonsillectomy.

Analgesic Effect Comparison Between Nalbuphine and Sufentanil for Patient-Controlled Intravenous Analgesia After Cesarean Section

Background: Efficient maternal pain relief after cesarean delivery remains challenging, but it is important to improve outcomes for the mother and the newborn during the puerperium. We compared the analgesic effect of nalbuphine (a κ receptor agonist/μ receptor antagonistic) with that of sufentanil (a µ-receptor agonist) in patient-controlled intravenous analgesia (PCIA) after cesarean section.

Methods: We enrolled 84 patients scheduled for elective cesarean sections with spinal anesthesia and randomized them into either nalbuphine or sufentanil groups (42 patients each). Pain scores, PCIA drug consumptions, degree of satisfaction, and adverse events were recorded as outcome measures.

Results: The pain scores at rest and uterine cramping pain scores in the nalbuphine group were lower than those in the sufentanil group at 6, 12, and 24 h after the operation. Also, the pain scores while switching to a seated position were lower in the nalbuphine group than in the sufentanil group at 6 and 12 h after the operation (p < 0.05). We found no significant differences in the PCIA drug consumption between the two groups. The degree of satisfaction in patients in the nalbuphine group was higher than that of patients in the sufentanil group (p = 0.01). Adverse events did not differ in the two groups.

Conclusion: PCIA with nalbuphine provides better analgesia and higher patient satisfaction than sufentanil after cesarean section.

Comparison of Duration of Analgesic Comparison of Duration of Analgesic Effect of Nalbuphine and Morphine as an Adjuvant to Bupivacaine in the Supraclavicular Block under Ultrasound Guidance

Background

Although many studies are available in the literature that has analyzed the effects of morphine, nalbuphine, and other opioids, no study had compared the effects of nalbuphine versus morphine as an adjuvant to bupivacaine in the supraclavicular block under the guidance of ultrasound.

Methodology

A randomized, double-blinded, prospective study was carried out on 60 patients of the American Society of Anesthesiologists Class I and II who were undergoing upper limb surgeries under the supraclavicular block. Patients were randomly allocated into two groups (n = 30). Group N received 20 ml of 0.5% bupivacaine with 50 μg.kg^-1 of nalbuphine, while Group M received 20 ml of 0.5% bupivacaine with 50 μg.kg^-1 of morphine. The characteristics of sensory and motor blocks, hemodynamic changes, duration of analgesia, adverse effects, and analgesic requirements were studied at different time intervals.

Results

In Group N, there was a statistically significant reduction in the time of onset of sensory block (9.9 ± 3.0 vs. 12.2 ± 2.6 min, P = 0.002) and motor block (14.4 ± 3.6 vs. 19.4 ± 3.6 min, P = 0.0005). The duration of sensory and motor blockade and duration of analgesia were comparable. There was no statistically significant difference regarding block characteristics and hemodynamic parameters.

Conclusion

Nalbuphine when added to bupivacaine as an adjuvant had significantly shortened the time of onset of sensory and motor blockade than morphine. However, the duration of analgesia, sensory and motor blockade of nalbuphine versus morphine were comparable.

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.

Preemptive Nalbuphine Attenuates Remifentanil-Induced Postoperative Hyperalgesia After Laparoscopic Cholecystectomy: A Prospective Randomized Double-Blind Clinical Trial

Background

Remifentanil-induced hyperalgesia (RIH) is a paradoxical phenomenon that may increase sensitivity to painful stimuli. Nalbuphine, which is both a μ-receptor antagonist and κ-receptor agonist, may affect RIH. The aim of this study was to evaluate the effects of nalbuphine on RIH during laparoscopic cholecystectomy.

Methods

A total of 96 patients were divided into the following four groups: 0.4 μg/kg/min of remifentanil with 0.2 mg/kg of nalbuphine (HRNA), 0.4 μg/kg/min of remifentanil with saline (HRSA), 0.1 μg/kg/min of remifentanil with 0.2 mg/kg of nalbuphine (LRNA), and 0.1 μg/kg/min of remifentanil with saline (LRSA). The pain thresholds of postoperative mechanical hyperalgesia were measured with von Frey filaments. Pain intensity and analgesic consumption were recorded up to 48 h after surgery.

Results

Pain thresholds on the inner forearm decreased in the HRSA group compared with the HRNA (P = 0.0167), LRNA (P = 0.0027), and LRSA (P = 0.0318) groups at 24 h after surgery. Pain thresholds on the peri-incisional area decreased in the HRSA group compared with HRNA, LRNA, and LRSA (all P < 0.0001) groups at 24 h after surgery. Patients in the HRNA group showed lower numeric rating scale scores at 1 h (P = 0.0159), 3 h (P = 0.0118), 6 h (P = 0.0213), and 12 h (P = 0.0118) than those in the HRSA group. Postoperative requirement for sufentanil was greater in the HRSA group than the HRNA group during the first 3 h (P = 0.0321) and second 3 h (P = 0.0040). Postoperative sufentanil consumption was also greater in the LRSA group than in the LRNA group during the first 3 h (P = 0.0321) and second 3 h (P = 0.0416).

Conclusion

Preemptive nalbuphine can ameliorate postoperative hyperalgesia induced by high-dose remifentanil in patients undergoing laparoscopic cholecystectomy.

The 95% effective dose of nalbuphine in patient-controlled intravenous analgesia for patients undergoing laparoscopic total hysterectomy compared to equivalent sufentanil

PURPOSE

To evaluate the 95% effective dose of nalbuphine in patient-controlled intravenous analgesia (PCIA) by the sequential method and compare the analgesia efficacy with the equivalent dose of sufentanil on patients undergoing laparoscopic total hysterectomy.

METHODS

In the first part, we defined a successful analgesia as the highest VAS ≤3 in 24 hours postoperatively. On the contrary, a failed analgesia was the highest VAS>3. According to the last patient's outcome, the next patients would be given an increase or decreased dose grade. This process ended up with 9 cross-over points. In the second part, 60 patients undergoing laparoscopic total hysterectomy were selected. They were randomly divided into 2 groups (n = 30 each group): receiving sufentanil 1.78 μg/kg (group S) and nalbuphine 1.78 mg/kg (group N). PCIA pump was given at the end of the operation with 5 mL bonus loading. The total amount of PCIA was 100 mL and programmed to deliver 0.5 mL each time with a lockout interval of 15 minutes and the background infusion amount of 2 mL/h. The VAS score and Ramsay score of were collected after the operation, the number of effective pressing times of PCIA were also recorded. Adverse reactions were documented in detail.

RESULTS

The 95% effective dose of nalbuphine in PCIA on patients undergoing laparoscopic total hysterectomy was 1.78 mg/kg. There was no significant difference in VAS between the sufentanil group and the nalbuphine groups (P > .05), but the number of the use of PCIA in the group S was more than that in the group N obviously (P <.05). The group S has a lower ramsay sedation score than group N at every time point. (P <.05). The incidence of nausea and vomiting was not statistically significant differences between two groups in the first 24 hours after colonoscopy (P >  q .05).

CONCLUSION

Nalbuphine 1.78 mg/kg in PCIA is recommended for the patients undergoing laparoscopic total hysterectomy. And nalbuphine is a reasonable alternative to sufentanil when used in PCIA.

Nitric Oxide Stimulates Acute Pancreatitis Pain via Activating the NF-κB Signaling Pathway and Inhibiting the Kappa Opioid Receptor

Pain is the most important clinical feature of acute pancreatitis (AP); however, its specific mechanism is currently unclear. In this study, we showed that AP caused an increase in nitric oxide (NO) secretion, activated the NF-κB pathway in the dorsal root ganglia (DRGs), and caused pain. We established an AP model in vivo and tested the expression of NO, the kappa opioid receptor (KOR), and pain factors. We showed that NO in AP was significantly elevated and increased the expression of pain factors. Next, by treating DRGs in vitro, it was found that NO activated the NF-κB pathway; conversely, NF-κB had no effect on NO. Moreover, inhibition of NF-κB promoted the KOR, whereas NF-κB did not change after KOR activation. Finally, behavioral experiments showed that a NO donor increased the pain behavior of mice, while a NO scavenger, NF-κB inhibitor, or KOR agonist attenuated the pain response in mice. These results suggest that iNOS/NO/NF-κB/KOR may be a key mechanism of pain in AP, providing a theoretical basis for the use of peripheral-restricted KOR agonists for pain treatment in AP.

Low intrinsic efficacy for G protein activation can explain the improved side effect profiles of new opioid agonists

Biased agonism at G protein-coupled receptors describes the phenomenon whereby some drugs can activate some downstream signaling activities to the relative exclusion of others. Descriptions of biased agonism focusing on the differential engagement of G proteins versus β-arrestins are commonly limited by the small response windows obtained in pathways that are not amplified or are less effectively coupled to receptor engagement, such as β-arrestin recruitment. At the μ-opioid receptor (MOR), G protein-biased ligands have been proposed to induce less constipation and respiratory depressant side effects than opioids commonly used to treat pain. However, it is unclear whether these improved safety profiles are due to a reduction in β-arrestin-mediated signaling or, alternatively, to their low intrinsic efficacy in all signaling pathways. Here, we systematically evaluated the most recent and promising MOR-biased ligands and assessed their pharmacological profile against existing opioid analgesics in assays not confounded by limited signal windows. We found that oliceridine, PZM21, and SR-17018 had low intrinsic efficacy. We also demonstrated a strong correlation between measures of efficacy for receptor activation, G protein coupling, and β-arrestin recruitment for all tested ligands. By measuring the antinociceptive and respiratory depressant effects of these ligands, we showed that the low intrinsic efficacy of opioid ligands can explain an improved side effect profile. Our results suggest a possible alternative mechanism underlying the improved therapeutic windows described for new opioid ligands, which should be taken into account for future descriptions of ligand action at this important therapeutic target.

A novel finding of nalbuphine-6-glucuronide, an active opiate metabolite, possessing potent antinociceptive effects: Synthesis and biological evaluation

Nalbuphine, a partial agonist/antagonist opioid analgesic, is structurally related to morphine. It is equipotent to morphine and has no serious side effects. In the past few decades, studies focusing on morphine metabolism have indicated that one of its sugar-conjugated metabolites, morphine-6-glucuronide, exerts a higher analgesic effect than its parent drug. Considering that nalbuphine is a morphine analog that follows a similar metabolic scheme, nalbuphine glucuronides were synthesized in this study and their potential analgesic effects were assessed. Nalbuphine-3-glucuronide (N3G) and nalbuphine-6-glucuronide (N6G) were synthesized based on Schmidt's glycosylation with OPiv protections on the glycosyl donor. In a pharmacodynamic study, paw pressure and cold-ethanol tail-flick tests were conducted in rats to evaluate the analgesic response after intracisternal and intraperitoneal administrations of nalbuphine, N3G, or N6G. The antinociceptive response was evaluated for each compound by calculating the area under the curve and the duration spent at greater than 50% maximum possible analgesia. In conclusion, intracisternal administration of N6G exhibited a stronger analgesic response than nalbuphine in the pain tests after both cold and mechanical stimuli, but N3G had no obvious effect. Similar to that of morphine, the glucuronide metabolite of nalbuphine at the 6-O-position exerted at least three-fold higher antinociceptive potency and five-fold longer analgesic duration than nalbuphine.

The Mechanisms Involved in Morphine Addiction: An Overview

Opioid use disorder is classified as a chronic recurrent disease of the central nervous system (CNS) which leads to personality disorders, co-morbidities and premature death. It develops as a result of long-term administration of various abused substances, along with morphine. The pharmacological action of morphine is associated with its stimulation of opioid receptors. Opioid receptors are a group of G protein-coupled receptors and activation of these receptors by ligands induces significant molecular changes inside the cell, such as an inhibition of adenylate cyclase activity, activation of potassium channels and reductions of calcium conductance. Recent data indicate that other signalling pathways also may be involved in morphine activity. Among these are phospholipase C, mitogen-activated kinases (MAP kinases) or β-arrestin. The present review focuses on major mechanisms which currently are considered as essential in morphine activity and dependence and may be important for further studies.