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

Efficacy and safety of flurbiprofen‑axetil combined with nalbuphine pretreatment on remifentanil‑induced postoperative hyperalgesia: A randomized clinical trial

Remifentanil-induced hyperalgesia (RIH) is a common and complicated issue in patients undergoing laparoscopic cholecystectomy (LC), which significantly reduces patient satisfaction. The present trial was designed to clarify the individual and combined effects of flurbiprofen-axetil and nalbuphine on remifentanil-induced hyperalgesia. This randomized double-blind clinical trial included 120 adult patients who underwent LC at The Second People's Hospital of Wuhu. The individuals were randomized into a flurbiprofen-axetil group (F group), nalbuphine group (N group), flurbiprofen-axetil combined with nalbuphine group (FN group) and saline group (S group). The four groups were given flurbiprofen-axetil (50 mg, iv.), nalbuphine (0.1 mg/kg, iv.), flurbiprofen-axetil (50 mg, iv.) combined with nalbuphine (0.1 mg/kg, iv.) or normal saline respectively prior to skin incision. The primary outcome was the postoperative mechanical pain thresholds at the inner forearm and peri-incisional area. The secondary outcomes were the visual analog scale (VAS) and Ramsay sedation scale at 0.5, 1, 4 and 24 h after surgery, and any other adverse events. The pain threshold of the medial forearm in the FN group did not differ from that in the F and N groups at 24 h after surgery (P=0.310 and P=0.910, respectively). However, the pain threshold around the incision in FN group was significantly lower than that in F and N groups 24 h after surgery (P=0.001). The VAS of the F group, N group and FN group were all significantly lower than that in the S group at 0.5, 1 and 24 h after surgery (P<0.001). No significant differences were observed in the incidence of adverse events between the four groups. Single flurbiprofen-axetil and single nalbuphine effectively prevented RIH 24 h after surgery in LC. The combination of the two analgesic drugs, with different mechanisms of action, was not superior to single therapy. The present study was registered with the Chinese Clinical Trial Registry (registration no. ChiCTR2100045347).

Pharmacological interventions for preventing opioid-induced hyperalgesia in adults after opioid-based anesthesia: a systematic review and network meta-analysis

Background: Opioid-induced hyperalgesia (OIH) is an adverse event of prolonged opioid use that increases pain intensity. The optimal drug to prevent these adverse effects is still unknown. We aimed to conduct a network meta-analysis to compare different pharmacological interventions for preventing the increase in postoperative pain intensity caused by OIH. Methods: Several databases were searched independently for randomized controlled trials (RCTs) comparing various pharmacological interventions to prevent OIH. The primary outcomes were postoperative pain intensity at rest after 24 h and the incidence of postoperative nausea and vomiting (PONV). Secondary outcomes included pain threshold at 24 h after surgery, total morphine consumption over 24 h, time to first postoperative analgesic requirement, and shivering incidence. Results: In total, 33 RCTs with 1711 patients were identified. In terms of postoperative pain intensity, amantadine, magnesium sulphate, pregabalin, dexmedetomidine, ibuprofen, flurbiprofen plus dexmedetomidine, parecoxib, parecoxib plus dexmedetomidine, and S (+)-ketamine plus methadone were all associated with milder pain intensity than placebo, with amantadine being the most effective (SUCRA values = 96.2). Regarding PONV incidence, intervention with dexmedetomidine or flurbiprofen plus dexmedetomidine resulted in a lower incidence than placebo, with dexmedetomidine showing the best result (SUCRA values = 90.3). Conclusion: Amantadine was identified as the best in controlling postoperative pain intensity and non-inferior to placebo in the incidence of PONV. Dexmedetomidine was the only intervention that outperformed placebo in all indicators. Clinical Trial Registration: https://www.crd.york.ac. uk/prospero/display_record.php?, CRD42021225361.

Nalmefene vs. dexmedetomidine for prevention of postoperative hyperalgesia in patients undergoing laparoscopic gynecological surgery with remifentanil infusion: A randomized double-blind controlled trial

Intraoperative remifentanil infusion may paradoxically induce post-surgical hyperalgesia. Dexmedetomidine reportedly reduces opioid-induced hyperalgesia. Nalmefene selectively reverses several side-effects of opioids without impairing analgesia. Herein, this randomized, double-blind controlled trial investigated whether nalmefene, dexmedetomidine, and both drugs combined prevent remifentanil-induced hyperalgesia. One hundred and fifty patients undergoing elective laparoscopic gynecological surgery under desflurane anesthesia randomly received either intraoperative sufentanil 0.20 μg kg^-1 (Group S), or remifentanil 0.20 μg kg^-1 min^-1 (Group R), or remifentanil and pre-anesthesia nalmefene 0.20 μg kg^-1 (Group N), or remifentanil and pre-anesthesia dexmedetomidine 0.50 μg kg^-1 (Group D), or remifentanil and the combination of dexmedetomidine 0.25 μg kg^-1 and nalmefene 0.10 μg kg^-1 (Group DN). The threshold of postoperative mechanical hyperalgesia (primary outcome) was measured with von Frey filaments. We also recorded pain intensity, analgesic consumptions, hyperalgesic area, and side-effects for 24 h postoperatively. Compared with Group S, remifentanil reduced hyperalgesic threshold on the forearm [mean 89.4 (SD 13.7) vs. 62.2 (10.7) g, p < 0.001] at postoperative 24 h. Pain threshold on the forearm at postoperative 24 h was significantly lower in Group R than in Groups N, D and DN [62.2 (10.7) vs. 71.1 (12.3), 72.4 (12.9) and 78.0 (13.8) g]. Compared with Group R, Postoperative pain intensity, analgesic consumption and hyperalgesic area were lower likewise in Groups D and DN. However, the incidence of intraoperative bradycardia was lower and post-anesthesia recovery time was shorter in Group DN than Group D. Preoperative therapy of dexmedetomidine and nalmefene combined attenuates postoperative hyperalgesia in patients undergoing laparoscopic gynecological surgery under desflurane-remifentanil anesthesia.

Spinal NLRP3 inflammasome activation mediates IL-1β release and contributes to remifentanil-induced postoperative hyperalgesia by regulating NMDA receptor NR1 subunit phosphorylation and GLT-1 expression in rats

BACKGROUND

Trafficking and activation of N-methyl-D-aspartate (NMDA) receptors play an important role in initiating and maintaining postoperative remifentanil-induced hyperalgesia (RIH). Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome has been linked to the development of inflammatory and neuropathic pain. We hypothesized that activation of NLRP3 inflammasome mediates IL-1β release and contributes to RIH in rats by increasing NMDA receptor NR1 (NR1) subunit phosphorylation and decreasing glutamate transporter-1 (GLT-1) expression.

METHODS

Acute exposure to remifentanil (1.2 μg/kg/min for 60 min) was used to establish RIH in rats. Thermal and mechanical hyperalgesia were tested at baseline (24 h before remifentanil infusion) and 2, 6, 24, and 48 h after remifentanil infusion. The levels of IL-1β, GLT-1, phosphorylated NR1 (phospho-NR1), and NLRP3 inflammasome activation indicators [NLRP3, Toll-like receptor 4 (TLR4), P2X purinoceptor 7 (P2X7R), and caspase-1] were measured after the last behavioral test. A selective IL-1β inhibitor (IL-1β inhibitor antagonist; IL-1ra) or three different selective NLRP3 inflammasome activation inhibitors [(+)-naloxone (a TLR4 inhibitor), A438079 (a P2X7R inhibitor), or ac-YVADcmk (a caspase-1 inhibitor)] were intrathecally administered immediately before remifentanil infusion into rats.

RESULTS

Remifentanil induced significant postoperative hyperalgesia, increased IL-1β and phospho-NR1 levels and activated the NLRP3 inflammasome by increasing TLR4, P2X7R, NLRP3, and caspase-1 expression, but it decreased GLT-1 expression in the L4-L6 spinal cord segments of rats, which was markedly improved by intrathecal administration of IL-1ra, (+)-naloxone, A438079, or ac-YVADcmk.

CONCLUSION

NLRP3 inflammasome activation mediates IL-1β release and contributes to RIH in rats by inducing NMDA receptor NR1 subunit phosphorylation and decreasing GLT-1 expression. Inhibiting the activation of the NLRP3 inflammasome may be an effective treatment for RIH.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

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.

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 (C_max ) and area under concentration-time curve (AUC_0-t ) values of nalbuphine in the single-injection and PCA groups were as follows: C_max , 81.3 ± 24.7 and 39.8 ± 6.4 ng/ml, respectively; moreover, AUC_0-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 AUC_0-t and EACDs in the PCA group were similar, whereas C_max 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.