Randomized prospective study of the analgesic effect of nefopam after orthopaedic surgery † †Declaration of interest. This work has been sponsored by Biocodex Laboratories, in charge of nefopam (Acupan injectable™) commercialization

Evaluating the Efficacy of Methocarbamol and Nefopam in Orthopedic Surgical Pain

Introduction Pain after orthopedic surgeries represents a special concern in patients with fractures. The use of multimodal analgesia significantly reduced the opioid need and reduced the risk of their side effects. Objectives This study compared the effectiveness and safety of methocarbamol and nefopam in the reduction of post-operative pain for patients undergoing orthopedic surgeries. Method This prospective, double-blind, randomized controlled trial took place at Al-Sader Teaching Hospital in Basrah, Iraq, from the first of February 2022 to the end of October 2023. The study aimed to assess the post-operative pain relief efficacy and safety of intramuscular nefopam (20 mg) and intravenous methocarbamol (1 g) in 110 adults (aged 18-65) undergoing elective orthopedic surgeries. Exclusions were made for allergies to the drugs, substance abuse history, and severe hepatic or renal impairment. Participants were randomized into two groups, with pain intensity measured at one hour, six hours, and 12 hours post-operation using the visual analog scale (VAS). Side effects were also evaluated. Statistical analysis was done using SPSS 27, with a significance level set at p<0.05 and a 95% confidence interval (CI). Results  In this study, we conducted a rigorous comparison between two groups, methocarbamol and nefopam, to evaluate their efficacy and safety in post-operative pain management. We started by ensuring that the groups were well-matched in terms of age, gender distribution, and body mass index (BMI). The results showed remarkable similarities in mean age, gender distribution, and BMI, supported by robust p-values, affirming the effective matching of the two groups. Moving to pain management, we observed a significant advantage in favor of methocarbamol. At all-time intervals (one hour, six hours, and 12 hours post-operation), methocarbamol consistently demonstrated lower mean VAS scores compared to nefopam. These differences were highly statistically significant, underscoring the superior pain relief efficacy of methocarbamol. Exploring side effects, we found no statistically significant disparities in the occurrence of nausea and vomiting between the two groups. However, there was a noticeable trend toward higher tachycardia incidence in the nefopam group, though it did not reach statistical significance. Conclusion The present study showed a higher efficacy of methocarbamol in post-operative pain reduction in comparison to nefopam. No serious side effects were observed with both drugs.

Efficacy of Oral Nefopam on Multimodal Analgesia in Total Knee Arthroplasty: A Prospective, Double-Blind, Placebo-Controlled, Randomized Trial

BACKGROUND

Multimodal analgesia is central to pain management after total knee arthroplasty (TKA). This study aimed to evaluate the efficacy of adding oral nefopam to multimodal analgesia for post-TKA pain management.

METHODS

In this prospective, double-blind, placebo-controlled, randomized trial, 100 patients who underwent TKA at our hospital were randomized to either the nefopam or the control group. After surgery, patients in the nefopam group received 200 mg of celecoxib, 150 mg of pregabalin, and 40 mg of nefopam twice daily to control postoperative pain. Patients in the control group received 200 mg of celecoxib, 150 mg of pregabalin, and a placebo. Oxycodone hydrochloride (10 mg) was used as the rescue analgesic. If the pain remained poorly controlled, 10 mg of morphine hydrochloride was injected subcutaneously as a secondary rescue analgesic. The primary outcome was the postoperative consumption of oxycodone and morphine as rescue analgesics. Secondary outcomes were postoperative pain assessed using the visual analogue scale (VAS), functional recovery assessed by the range of knee motion and ambulation distance, time until hospital discharge, indicators of liver function, and complication rates.

RESULTS

Patients in the nefopam group had significantly lower postoperative oxycodone and morphine consumption within 24 hours after surgery and during hospitalization, lower VAS pain scores at rest and during motion within 24 h after surgery, better functional recovery on postoperative days 1 and 2, and a shorter hospital stay. However, the absolute reduction in 0 to 24 h opioid consumption, VAS pain scores, and knee range of motion did not exceed the reported minimal clinically important difference. Both groups had similar indicators of liver function and complication rates.

CONCLUSIONS

Adding oral nefopam to multimodal analgesia resulted in statistically significant improvements in opioid consumption, VAS pain scores, and functional recovery. However, the amount of improvement may not be clinically important.

Intravenous lidocaine bolus for reducing nefopam-induced venous pain: A randomized, intrasubject comparison trial

Background and Aims

Intravenous nefopam reduces postoperative pain and opioid consumption but can cause infusion-related pain. We aimed to investigate whether lidocaine can effectively reduce this pain.

Material and Methods

This prospective, randomized, double-blind, controlled, intrasubject comparison trial included 42 patients (20-60 years) undergoing elective surgery under regional or peripheral anesthesia. In the postanesthesia care unit, two 50 mL syringes containing nefopam (20 mg) diluted in saline (100 mL) were sequentially infused in 15 min into venous catheters in the left and right arms. Patients were randomly assigned to the "left side" or "right side" group based on the arm in which a bolus of 1% lidocaine (2 mL) (study group) was administered before nefopam infusion. Normal saline (2 mL) was administered on the control side. Numerical Rating Scale scores and the incidence of pain (scores > 3) and nausea or vomiting were recorded at 1, 5, 10, and 15 min.

Results

The analysis included 42 patients (84 infusions). Compared with the placebo, lidocaine lowered the mean infusion-related pain at 1 (0.07 vs. 2.21, P < 0.001), 5 (2 vs. 4.21, P < 0.001), 10 (2.02 vs. 3.95, P < 0.001), and 15 min (1.62 vs. 3.16, P = 0.003). At 5 min, significantly higher percentages of infusion sites with moderate and higher pain scores (> 3) were observed on the control side (30.95% vs. 14.29%, P = 0.000). Seven patients exhibited nausea or vomiting (16.7%).

Conclusion

For the nefopam infusion rate and concentration that we used, a 20 mg lidocaine pretreatment bolus significantly reduces infusion-related pain.

Comparative effectiveness of interventions for managing urological postoperative catheter-related bladder discomfort: a systematic review and network meta-analysis

BACKGROUND

Catheter-related bladder discomfort (CRBD) is a common postoperative bladder pain syndrome. Many drugs and interventions for managing CRBD have been studied, but their comparative effectiveness remains controversial. We made a study to assess the comparative effectiveness of interventions included Ketorolac, Lidocaine, Chlorpheniramine, Gabapentin, Magnesium, Nefopam, Oxycodone, Parecoxib, Solifenacin, Tolterodine, Bupivancaine, Dexmedetomidine, Hyoscine N-butyl bromide, Ketamine, Penile nerve block on urological postoperative CRBD.

METHODS

We performed a network meta-analysis via Aggregate Data Drug Inormation System software included 18 studies with 1816 patients and assessed the risk of bias by Cochrane Collaboration tool. The incidence of moderate to severe CRBD at 0, 1, and 6 h after surgery and the incidence severe CRBD at 1 h after surgery were compared.

RESULT

The number of best rank is 0.48(Nefopam) and 0.22(Nefopam) in the incidence of moderate to severe CRBD at 1 h and incidence severe CRBD at 1 h. More than half of studies at unclear or high risk of bias.

CONCLUSION

Nefopam reduced the incidence of CRBD and prevented severe events, but limited by the small number of studies for each intervention and heterogeneous patients.

Management of perioperative pain after TKA

Postoperative pain is the prime obstacle to recovery of motion and return to activity after total knee arthroplasty (TKA). Combating pain is a key point in enhanced recovery after surgery (ERAS) protocols. Outcome depends on the efficacy of pain relief, making it a major issue. The pain originates locally in the knee and also remotely via neural pathways. Regression can be slow, over several months. Pain may sometimes be definitive, to a varying degree. Pain should be managed at each step of ERAS, from the preoperative period to the last follow-up consultation, and most especially during the perioperative phase. Pain needs to be anticipated and limited for as long as necessary. The impact of analgesics should be enhanced by means of potentiators. Some are administered by general route, sometimes preoperatively; others are applied locally, directly in the surgical site by local injection, or close to the nerves, to reduce painful stimuli. The two main principles of pain management are preventive analgesia and multimodal analgesia associating various molecules and routes.

Postoperative analgesia of intraoperative nefopam in patients undergoing anterior cervical spine surgery: A prospective randomized controlled trial

BACKGROUND

Nefopam is a non-opioid, non-nonsteroidal anti-imflammatory drug, analgesic drug that inhibits the reuptake of serotonin, norepinephrine, and dopamine. It is widely used as an adjuvant for pain. This study investigated whether the intraoperative, intravenous infusion of nefopam (20 mg) reduces postoperative morphine consumption, pain scores, and alleviates neuropathic pain in patients undergoing cervical spine surgery.

METHODS

A prospective, paralleled design, randomized study was conducted on 50 patients (aged 18-75 years) in a university-based hospital. The patients were assigned to an intervention or a control group (25 patients in each). The intervention group received a 1-hour infusion of nefopam (20 mg) before the end of surgery. The control group received normal saline (NSS). The outcome measures were morphine consumption during the first 24 postoperative hours, numerical rating scale (NRS) pain scores, and scores for the Thai version of the Neuropathic Pain Symptom Inventory (NPSI-T) in patients with neuropathic pain and adverse drug reactions. The NPSI-T scores were assessed on the preoperative day, postoperative day 1, 3, 15, and 30. The outcome assessors were blinded to group allocation.

RESULTS

Fifty patients were analyzed. During the first 24 postoperative hours, morphine consumption was 8 mg (nefopam) and 12 mg (NSS; P = .130). The intervention and control groups demonstrated no significant differences in the median NRS scores or total NPSI-T scores or adverse drug reactions.

CONCLUSIONS

A single, intraoperative infusion of 20 mg of nefopam did not significantly reduce postoperative (24 hours) morphine consumption in patients undergoing anterior cervical spine surgery.

The effect of newly designed dual-channel elastomeric pump for intravenous patient-controlled analgesia after total laparoscopic hysterectomy: a randomized, double-blind, prospective study

BACKGROUND

A newly designed intravenous patient-controlled analgesia (PCA) device with a dual-channel elastomeric infusion pump has been recently introduced. One channel is a continuous line with a constant flow rate basal infusion, while the other channel has an adjustable flow rate and bolus function and is labeled as a selector-bolus channel. This study compared dual and single-channel intravenous PCA in terms of clinical effect and quality of recovery.

METHODS

Eighty-four patients undergoing total laparoscopic hysterectomy were randomly allocated to a 1-channel group (n = 41) or a 2-channel group (n = 43). Only the selector-bolus channel was utilized, but the continuous channel was not utilized in the 1-channel group, but both channels were utilized in the 2-channel group. In the 1-channel group, 16 μg/kg of fentanyl, 2 mg/kg of ketorolac, and 12 mg of ondansetron with normal saline were administered to the selector-bolus channel and normal saline only in the continuous channel for blinding. In the 2-channel group, 16 μg/kg of fentanyl was administered to the selector-bolus channel, and ketorolac (2 mg/kg) and ondansetron (12 mg) were administered via the continuous channel. The quality of recovery was evaluated preoperatively and 24 h postoperatively using the Quality of Recovery-40 (QoR-40). Cumulative PCA consumption, postoperative pain rated using the numeric rating scale (NRS; during rest/cough), and postoperative nausea were evaluated 6, 12, 24, 36, and 48 h after surgery. Incidence of vomiting and use of antiemetics and rescue analgesics was measured.

RESULTS

The 24-h postoperative QoR-40 score was higher in the 2-channel group than in the 1-channel group (P=0.031). The incidence of nausea at 12 h and 36 h was significantly higher in the 1-channel group (P=0.043 and 0.040, respectively), and antiemetic use was more frequent in the 1-channel group (P=0.049). Patient satisfaction was higher in the 2-channel group (P=0.036). No significant differences were observed in pain scores during resting/cough or cumulative PCA consumption.

CONCLUSIONS

The 2-channel PCA showed better patient satisfaction with higher QoR-40 during the recovery compared with the 1-channel PCA. Better satisfaction was associated with lower nausea and reduced rescue antiemetics by maintaining the infusion of adjuvant analgesic agents and antiemetic agents constantly by utilizing dual channels.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov , NCT04082039 on 9 September 2019.

The Lack of Analgesic Efficacy of Nefopam after Video-Assisted Thoracoscopic Surgery for Lung Cancer: A Randomized, Single-Blinded, Controlled Trial

Nefopam is a centrally acting non-opioid analgesic, and its efficacy in multimodal analgesia has been reported. This study aimed to assess the analgesic efficacy of intraoperative nefopam on postoperative pain after video-assisted thoracoscopic surgery (VATS) for lung cancer. Participants were randomly assigned to either the nefopam or the control group. The nefopam group received 20 mg of nefopam after induction and 15 min before the end of surgery. The control group received saline. The primary outcome was cumulative opioid consumption during the 6 h postoperatively. Pain intensities, the time to first request for rescue analgesia, adverse events during the 72 h postoperatively, and the incidence of chronic pain 3 months after surgery were evaluated. Ninety-nine patients were included in the analysis. Total opioid consumption during the 6 h postoperatively was comparable between the groups (nefopam group [n = 50] vs. control group [n = 49], 19.8 [13.5–25.3] mg vs. 20.3 [13.9–27.0] mg; median difference: −1.55, 95% CI: −6.64 to 3.69; p = 0.356). Pain intensity during the 72 h postoperatively and the incidence of chronic pain 3 months after surgery did not differ between the groups. Intraoperative nefopam did not decrease acute postoperative opioid consumption or pain intensity, nor did it reduce the incidence of chronic pain after VATS.

Does Nefopam Provide Analgesic Effect and Reduce Morphine Consumption After Primary Total Knee Arthroplasty? A Prospective, Double-Blind, Randomized Controlled Trial

BACKGROUND

One of the most undesirable results after total knee arthroplasty (TKA) is severe immediate postoperative pain, resulting in patient dissatisfaction. We aimed to evaluate nefopam's analgesic efficacy after primary TKA along with related outcomes, including morphine consumption and adverse events.

METHODS

We conducted a double-blind, randomized controlled trial of patients undergoing unilateral primary TKA, comparing 24 hours of 80 mg of continuous intravenous nefopam to placebo infusion. A 100-mm Visual Analog Scale (VAS) for pain-at-rest and in-motion ≤48 hours was the primary outcome measure. Secondary outcomes were morphine and antiemetic consumption, adverse events, and functional outcomes: time-to-walk, timed up-and-go test, postoperative knee range of motion at 24 and 48 hours, time-to-discharge, and patient satisfaction scores.

RESULTS

Patients in the nefopam group had significantly lower VAS at rest 6 hours postop (20.3 ± 27.3 vs 35 ± 24.3, P = .01). Other timepoints and in-motion VAS did not significantly differ. Total morphine consumption (0-48 hours) was 37% less, significantly lower, in the nefopam group (5.3 ± 4.5 vs 8.4 ± 7.5 mg, P = .03). Antiemetic consumption was also 61% lower in the nefopam group but not statistically significant (0.8 ± 2.3 vs 2.0 ± 3.8 mg, P = .08). There were no variations in adverse events, functional outcomes, and satisfaction scores between groups.

CONCLUSION

Continuous nefopam administration as part of multimodal analgesia for 24 hours post-TKA produced a significant analgesic effect but only within the first 6 hours. However, there was a notable reduction in morphine use 48 hours postop. Nefopam is a useful agent for contemporary pain control after TKA.

LEVEL OF EVIDENCE

Therapeutic Level I.

Comparison between the trapezius and adductor pollicis muscles as an acceleromyography monitoring site for moderate neuromuscular blockade during lumbar surgery

Acceleromyography at the adductor pollicis located in a distal part of the body may not reflect the degree of neuromuscular blockade (NMB) at the proximally located muscles manipulated during lumbar surgery. We investigated the usefulness and characteristics of acceleromyographic monitoring at the trapezius for providing moderate NMB during lumbar surgery. Fifty patients were randomized to maintain a train-of-four count 1–3 using acceleromyography at the adductor pollicis (group A; n = 25) or the trapezius (group T; n = 25). Total rocuronium dose administered intraoperatively [mean ± SD, 106.4 ± 31.3 vs. 74.1 ± 17.6 mg; P < 0.001] and surgical satisfaction (median [IQR], 7 [5–8] vs. 5 [4–5]; P < 0.001) were significantly higher in group T than group A. Lumbar retractor pressure (88.9 ± 12.0 vs. 98.0 ± 7.8 mmHg; P = 0.003) and lumbar muscle tone in group T were significantly lower than group A. Time to maximum block with an intubating dose was significantly shorter in group T than group A (44 [37–54] vs. 60 [55–65] sec; P < 0.001). Other outcomes were comparable. Acceleromyography at the trapezius muscle during lumbar surgery required a higher rocuronium dose for moderate NMB than the adductor pollicis muscle, thereby the consequent deeper NMB provided better surgical conditions. Trapezius as proximal muscle may better reflect surgical conditions of spine muscle.

The Analgesic Efficacy of Nefopam in Patient-Controlled Analgesia after Laparoscopic Gynecologic Surgery: A Randomized, Double-Blind, Non-Inferiority Study

Opioid-sparing effects of nefopam during patient-controlled analgesia (PCA) are well demonstrated. We hypothesized that postoperative pain control with an opioid-equivalent dose of nefopam as a single analgesic agent for PCA would not be inferior to fentanyl in laparoscopic gynecologic surgery. In total, 135 patients were randomly assigned to the N (nefopam 200 mg), NF (fentanyl 500 mcg + nefopam 100 mg), and F (fentanyl 1000 mcg) groups (n = 45 patients per group). The primary outcome was the numerical rating scale (NRS) score at rest at 6 h postoperatively, and the non-inferiority limit was set to 1. Secondary outcomes were pain severity and incidence of nausea and vomiting for 48 h postoperatively. Mean differences (MD) in primary outcome between the N and F groups were 0.4 (95% confidence interval (CI) −0.5 to 1.3). The upper limit of 95% CI exceeded the non-inferiority limit. The N group showed higher pain scores than the NF group (MD, 1.1; 95% CI, 0.3–1.9) in pairwise comparisons. No significant intergroup differences were observed in the cumulative dose of PCA usage and incidence of postoperative nausea and vomiting (PONV). In laparoscopic gynecological surgery, nefopam alone showed limited efficacy for postoperative pain control.

Outpatient surgery of the first ray of the foot: post-operative pain monitoring at home

INTRODUCTION

At present, health facilities are forced to switch to outpatient care. While it lends itself well to this organizational arrangement, first ray surgery is broadly considered as painful by patients, who are often reluctant to this treatment. The evolution of post-operative pain in patients who underwent operations for first ray surgery from D0 to D15 were studied. Secondly, the duration of the oral analgesic treatment, the patient's satisfaction level, and searched for complications were assessed.

METHODS

This is an observational, single-center and single-operator study. Between July and December 2019, forty patients who underwent first ray surgery (hallux valgus or rigidus) and eligible for outpatient treatment were included. The surgical technique of the hallux valgus treatment consisted of open surgery via double metatarsal and phalangeal osteotomy. The hallux rigidus surgery consisted of arthrodesis using an open dorsal plate. Home monitoring was carried out by a healthcare provider (e-HORUS). The protocol provided for pain management by means of a diffuser of Nefopam IV for a maximum of 5 days, combined with alleviating oral analgesics 1 and 2 and NSAIDs. The pain was evaluated on D0, D1, D3, D5, D8 and D15, using a numerical scale (NS) from 0 to 10. The degree of patient satisfaction was recorded at 1 month.

RESULTS

35 patients were followed. 5 patients were excluded due to incomplete data. The series included 26 women and 9 men, with an average age of 59.9 years. There were 30 hallux valgus and 5 hallux rigidus. The pain analyzed by the NS was 5.37 on D0, 3.34 on D1, 1.83 on D3, 1.43 on D5, 1.06 on D8 and 2.2 on D15. The average duration of Nefopam infusions was 3.89 days, and the average duration of oral analgesics was 17.7 days. The tolerance of the treatment was satisfactory in 79% of the cases. 69% of patients were very satisfied with the management of their pain. There were no scar complications or infections. No re-hospitalization was necessary. 3 algoneurodystrophies were identified. The existence of fibromyalgia or Parkinsonian syndrome was correlated with higher pain.

DISCUSSION-CONCLUSION

Pain management after outpatient first ray surgery using the injectable Nefopam protocol was satisfactory in the majority of cases, with a high degree of patient satisfaction. This protocol is routinely offered to our patients who must undergo first ray surgery.

Comparison Between Preoperative and Intraoperative Administration of Nefopam for Acute and Chronic Postoperative Pain in Colon Cancer Patients: A Prospective, Randomized, Double-Blind Study

BACKGROUND

The present study was designed as a prospective, randomized, double-blind clinical trial to evaluate the effects of preoperatively administered nefopam on postoperative acute hyperalgesia and the long-term painful sequelae compared to intraoperative administration.

METHODS

One hundred and fifty patients undergoing elective laparoscopic colectomy were enrolled. Group 1 (post-incisional nefopam) patients received saline at 30 min before skin incision followed by intraoperative administration of 20 mg nefopam at 1 h after incision. Group 2 (pre-incisional nefopam) patients were administered 20 mg nefopam before skin incision and received saline after skin incision. At postoperative 2, 6, 24, 48, and 72 h, fentanyl consumption and pain intensities at rest and during deep breathing were evaluated by visual analog scale (VAS). The incidence of the long-term painful sequelae after surgery was evaluated more than one year after surgery.

RESULTS

Cumulative fentanyl consumption during postoperative 72 h was similar between Group 1 and Group 2 (1534 ± 698 μg, 95% CI 1367-1702 μg vs. 1442 ± 721 μg, 95% CI 1266-1618 μg, P = 0.197). VAS pain scores at rest were comparable between the two groups, but VAS scores during deep breathing were significantly lower in Group 2 than in Group 1. Six and five patients complained of mild pain (pain rating 1) at the surgical site in Group 1 and 2, respectively.

CONCLUSIONS

Preoperatively administered nefopam reduced exertional pain compared to intraoperative administration although postoperative analgesic consumption was similar between two groups. It may be helpful to conduct early ambulation and deep breathing during the acute postoperative period in patients undergoing intestinal surgery. Trial registration No: KCT0001656.

Analgesic efficacy of nefopam for cancer pain: a randomized controlled study

Background: Nefopam is a non-opioid, non-steroidal, central acting drug used effectively for postoperative pain. The efficacy of nefopam for cancer pain remains unclear. We aimed to evaluate the analgesic efficacy of nefopam for cancer pain in a randomized controlled trial. Methods: Patients with moderate to severe cancer pain (n=40) were randomly divided into two groups. The nefopam group (n=20) received three 20 mg doses of nefopam every 8 hours. The placebo group (n=20) received normal saline. Intravenous patient-controlled analgesia with morphine was given for breakthrough pain for 48 hours. The primary outcome was significant pain reduction. Secondary outcomes were morphine consumption over 48 hours and incidence of side effects. Results: The nefopam group showed pain reduction at 12 hours (65% of patients), 24 hours (80%), 36 hours (85%), and 48 hours (65%). The placebo group showed pain reduction at 12 hours (70%), 24 hours (75%), 36 hours (80%), and 48 hours (60%). However, there were no statistically significant differences between the groups (p>0.05). The median dosage of morphine consumption in 48 hours was lower in the nefopam group (25.5 mg) compared with the placebo group (37 mg), but this was not statistically significant (p=0.499). There were no statistically significant differences in blood pressure and heart rate between the groups. Side effects in both groups were comparable. Conclusions: At dosage of 60 mg in 24 hours, nefopam did not provide significant pain reduction in moderate to severe cancer pain patients. However, there was a trend of reduced opioid consumption. Further studies with larger sample sizes, longer duration, or higher doses of nefopam are warranted. Registration: Thai Clinical Trail Registry (TCTR) ID TCTR20181016001; registered on 12 October 2018.

Analgesic efficacy of intravenous nefopam after spine surgery: a randomized, double-blind, placebo-controlled trial

Background: The incidence of moderate to severe pain is high among patients undergoing spinal surgery. Nefopam can be used as an adjuvant analgesic postoperatively after spine surgery. The study aimed to assess the analgesic efficacy and side effects of nefopam on 24-hour postoperative morphine consumption after spine surgery. Methods: The study is a randomized, double-blinded, placebo-controlled trial. A total of 96 patients were randomized into 4 treatment groups, 24 each. In group 1, patients received normal saline before surgical incision and before the end of surgery. In group 2, patients received 30 mg nefopam before surgical incision and normal saline before the end of surgery. In group 3, patients received normal saline before surgical incision and 30 mg of nefopam before the end of surgery. In group 4, patients received 30 mg of nefopam in both timings. Patient-controlled analgesia morphine was used for the postoperative period. Outcomes were to determine 24-hour morphine consumption and incidence of side effects.  Results: Of 96 patients enrolled, 21 in placebo-placebo, 22 in nefopam-placebo, 22 in placebo-nefopam and 21 in nefopam-nefopam groups completed the study.  Analysis of the Kruskal-Wallis test on the intention-to-treat basis shows no significant difference in 24-hour postoperative morphine consumption between four groups, which were 18 [IQR 13.5-29], 20 [IQR 11-28.3], 17 [IQR 11.5-28.5], 13 [IQR 8.5-18.5] mg., respectively (p = 0.223). Incidence of side effects, including tachycardia, sedation, sweating and nausea/ vomiting, did not differ. Conclusions: Adding perioperative nefopam to opioid analgesic does not improve analgesic efficacy in patients who underwent spine surgery. Registration: Thai Clinical Trials Registry ID TCTR20171115001; registered on 15 November 2017.

Analgesic efficacy of intravenous nefopam after spine surgery: a randomized, double-blind, placebo-controlled trial

Background: The incidence of moderate to severe pain is high among patients undergoing spinal surgery. Nefopam can be used as an adjuvant analgesic postoperatively after spine surgery. The study aimed to assess the analgesic efficacy and side effects of nefopam on 24-hour postoperative morphine consumption after spine surgery. Methods: The study is a randomized, double-blinded, placebo-controlled trial. A total of 96 patients were randomized into 4 treatment groups, 24 each. In group 1, patients received normal saline before surgical incision and before the end of surgery. In group 2, patients received 30 mg nefopam before surgical incision and normal saline before the end of surgery. In group 3, patients received normal saline before surgical incision and 30 mg of nefopam before the end of surgery. In group 4, patients received 30 mg of nefopam in both timings. Patient-controlled analgesia morphine was used for the postoperative period. Outcomes were to determine 24-hour morphine consumption and incidence of side effects.  Results: Of 96 patients enrolled, 21 in placebo-placebo, 22 in nefopam-placebo, 22 in placebo-nefopam and 21 in nefopam-nefopam groups completed the study. Analysis of the Kruskal-Wallis test shows no significant difference in 24-hour postoperative morphine consumption between four groups, which were 18 [IQR 13.5-29], 20 [IQR 11-28.3], 17 [IQR 11.5-28.5], 13 [IQR 8.5-18.5] mg., respectively (p = 0.223).  Incidence of side effects, including tachycardia, sedation, sweating and nausea/ vomiting, did not differ. Conclusions: Adding perioperative nefopam to opioid analgesic does not improve analgesic efficacy in patients who underwent spine surgery. Registration: Thai Clinical Trials Registry ID TCTR20171115001; registered on 15 November 2017.

Analgesic and opioid-sparing effects of single-shot preoperative paravertebral block for radical mastectomy with immediate reconstruction: A retrospective study with propensity-adjusted analysis

BACKGROUND

Before radical mastectomy with immediate latissimus dorsi flap reconstruction, single-shot paravertebral block (PVB) can be added to general anesthesia to improve analgesia. As this technique was introduced in 2014 in our centre, our aim was to retrospectively assess its clinical effects.

METHODS

Among 175 patients who underwent surgery over four years (40 receiving PVB), we studied the intra-operatively administered doses of opioids and vasopressors, postoperative pain as estimated by a composite score based on the intensity scores for maximum postoperative pain and the amounts of analgesic drugs, and the report of postoperative nausea/vomiting (PONV). The effect of PVB on these outcomes was tested by propensity-matched comparisons, after a propensity score based on the patient's age, body mass index, ASA and Apfel scores, was calculated. Depending on the outcomes, results are expressed as odds ratios (OR) or regression coefficients (RC), with their 95% confidence interval limits.

RESULTS

PVB reduced the doses of intraoperative opioids (OR for comparisons between the 2nd and 3rd tercile to the 1st tercile, respectively: 0.39 (0.21; 0.67) and 0.10 (0.05; 0.21)). It increased the doses of intraoperative vasopressors (CR = 1.94 (0.89; 2.93). It reduced the composite score for postoperative pain (CR = -0.80 (-1.04; -0.56), and the occurrence of PONV (OR = 0.21 (0.14; 0.37).

CONCLUSIONS

Despite a higher risk of intraoperative hypotension, single-shot PVB seems to markedly improve postoperative analgesia and reduce the amounts of opioids. This could offer many clinical advantages in this type of cancer surgery.

Analgesic Effect of Low Dose Nefopam Hydrochloride after Arthroscopic Rotator Cuff Repair: A Randomized Controlled Trial

Arthroscopic rotator cuff repair causes acute postoperative hyperalgesia. Multimodal analgesia is preferable to opioid-based intravenous patient-controlled analgesia (IV-PCA) due to postoperative nausea and vomiting (PONV). We evaluated the effect of nefopam as a postoperative non-opioid analgesic after shoulder surgeries. A total of 180 adult patients were enrolled for arthroscopic rotator cuff repair. They were randomly assigned to nefopam (N) or control (C) groups and each group was reclassified according to the interscalene block (B) into NB, CB and NX, CX. Nefopam was applied at a constant dose intravenously during recovery. Pain scores were measured with a Visual Analogue Scale (VAS) before (T0), immediately after (T1), 30 min (T2) and 12 h (T3), 24 h (T4) and 48 h (T5) after surgery. There was no significant difference in demographic data. The overall VAS scores did not differ with regard to nefopam use, except for the NB group at T4 in intention to treat (ITT) analysis (p < 0.05). PONV occurred more frequently in the N group than in the C group (p < 0.05). Neither individual nor all risk factors were associated with PONV occurrence (p > 0.10). In conclusion, nefopam alone did not show a definite decrease in postoperative pain. It instead increased PONV regardless of risk factors.

Effects on postoperative nausea and vomiting of nefopam versus fentanyl following bimaxillary orthognathic surgery: a prospective double-blind randomized controlled trial

Background

Postoperative nausea and vomiting (PONV) frequently occurs following bimaxillary orthognathic surgeries. Compared to opioids, Nefopam is associated with lower incidences of PONV, and does not induce gastrointestinal tract injury, coagulopathy, nephrotoxicity, or fracture healing dysfunction, which are common side effects of Nonsteroidal anti-inflammatory drugs. We compared nefopam- and fentanyl-induced incidence of PONV in patients with access to patient-controlled analgesia (PCA) following bimaxillary orthognathic surgeries.

Methods

Patients undergoing bimaxillary orthognathic surgeries were randomly divided into nefopam and fentanyl groups. Nefopam 120 mg or fentanyl 700 µg was mixed with normal saline to a final volume of 120 mL. Patients were given access to nefopam or fentanyl via PCA. Postoperative pain intensity and PONV were measured at 30 minutes and 1 hour after surgery in the recovery room and at 8, 24, 48, and 72 hours after surgery in the ward. The frequency of bolus delivery was compared at each time point.

Results

Eighty-nine patients were enrolled in this study, with 48 in the nefopam (N) group and 41 in the fentanyl (F) group. PONV occurred in 13 patients (27.7%) in the N group and 7 patients (17.1%) in the F group at 8 hours post-surgery (P = 0.568), and there were no significant differences between the two groups at any of the time points. VAS scores were 4.4 ± 2.0 and 3.7 ± 1.9 in the N and F groups, respectively, at 8 hours after surgery (P = 0.122), and cumulative bolus delivery was 10.7 ± 13.7 and 8.6 ± 8.5, respectively (P = 0.408). There were no significant differences in pain or bolus delivery at any of the remaining time points.

Conclusion

Patients who underwent bimaxillary orthognathic surgery and were given nefopam via PCA did not experience a lower rate of PONV compared to those that received fentanyl via PCA. Furthermore, nefopam and fentanyl did not provide significantly different postoperative pain control.

Comparison of the Analgesic Effect of Sufentanil versus Fentanyl in Intravenous Patient-Controlled Analgesia after Total Laparoscopic Hysterectomy: A Randomized, Double-blind, Prospective Study

Background: Fentanyl is one of the most widely used opioids for intravenous patient-controlled analgesia (IV-PCA). Sufentanil, a fentanyl analog, is suitable for postoperative pain control because it has no active metabolites and shows a higher therapeutic index and lower frequency of respiratory suppression than fentanyl. This study aimed to compare the two opioids for postoperative pain relief on the basis of analgesic efficacy, adverse effects, and patient satisfaction. Methods: Sixty-four patients undergoing total laparoscopic hysterectomy were randomly allocated into a fentanyl group (n = 31) or a sufentanil group (n = 33). The patients received 50-μg fentanyl or 10-μg sufentanil before induction of anesthesia and 5 minutes after uterine incision during surgery in the fentanyl and sufentanil group, respectively. After arriving at the post-anesthesia care unit (PACU), verbal pain score (VPS) and sedation score were assessed. IV-PCA (fentanyl 1250 μg or sufentanil 250 μg with ondansetron 8 mg; total volume, 60 ml) was connected and continued for 48 h postoperatively. Postoperative pain was evaluated by using the numeric rating scale (NRS; at rest/during cough) at 6, 12, 24, 36, and 48 hours after surgery. The cumulative PCA consumption, patient satisfaction scores, and adverse effects were measured. Results: In the PACU, VPS was significantly higher and rescue fentanyl consumption was higher in the fentanyl group than in the sufentanil group, while the sedation score and adverse effects were comparable between the groups. No significant differences were observed in the NRS scores for pain (at rest/during cough) in the ward over 48 hours postoperatively, but the cumulative PCA consumption was significantly higher in the fentanyl group (47.4 ± 9.9 ml vs. 36.2 ± 14.6 ml, P = 0.01). There were no significant intergroup differences in patient satisfaction score and the incidence of adverse effects in the ward, except for a higher incidence of dry mouth in the fentanyl group. Conclusions: In comparison with fentanyl, sufentanil showed comparable analgesic efficacy and safety with less analgesic consumption (under a potency ratio of 1:5) in IV-PCA after total laparoscopic hysterectomy. Therefore, we suggest that sufentanil can be a useful alternative to fentanyl for IV-PCA.

Association of nefopam use with postoperative nausea and vomiting in gynecological patients receiving prophylactic ramosetron: A retrospective study

Background

Postoperative nausea and vomiting (PONV) is a common adverse effect of opioid-based intravenous patient-controlled analgesia (IV PCA). Nefopam has been considered as a good candidate for inclusion in multimodal analgesia because of its opioid sparing effect, but it can be emetic. This study aims to examine whether the use of nefopam combined with fentanyl in IV PCA was associated with the higher incidence of PONV in patients receiving prophylactic ramosetron after gynecological surgery.

Methods

Data from 296 patients who underwent gynecological surgery were retrospectively reviewed. The patients received IV PCA containing either fentanyl 1500 μg and ketorolac 90 mg (Group K) or fentanyl 1500 μg and nefopam 80 mg (Group N). All patients in both groups received 0.3 mg of ramosetron at the end of surgery. The primary outcome measure was the incidence of PONV during the 3-day postoperative period.

Results

No difference was observed in the incidence of PONV during the 3-day postoperative period between the two groups. However, the incidence of nausea on postoperative day 2 was significantly higher in Group N (10.3%) than in Group K (2.8%) (P = 0.016). Multivariable logistic regression analysis showed that the use of nefopam was not associated with a higher incidence of PONV (adjusted odds ratio, 1.616; 95% confidence interval, 0.952–2.743, P = 0.076). There were no differences in postoperative pain scores between the two groups.

Conclusion

The combined use of nefopam with fentanyl in IV PCA was not associated with the higher incidence of PONV compared with the use of ketorolac and fentanyl combination in patients who received ramosetron as PONV prophylactic agent. However, prospective trials are required for a confirmative conclusion.

Median effective dose of nefopam to treat postoperative pain in patients who have undergone laparoscopic cholecystectomy

Objective

Nefopam is thought to reduce postoperative pain; however, the evidence is insufficient. The recommended dose is 20 mg, and the median effective dose (ED50) in the surgical setting reportedly ranges from 17 to 28 mg. However, nefopam frequently produces inadequate postoperative analgesia. We evaluated the ED50 of nefopam as a single agent in patients undergoing laparoscopic cholecystectomy.

Methods

Twenty-nine patients were scheduled for laparoscopic cholecystectomy. Postoperative pain was evaluated using a numerical pain scale (NPS). When the NPS score was >3, patients were administered a predetermined dose of nefopam. The dose was calculated using the up-and-down allocation technique based on the previous response. The initial dose was 28 mg, with adjustment intervals of 5 mg. An effective response was defined as a decrease in the NPS score to <3 at 30 minutes after infusion.

Results

The ED50 of nefopam was 62.1 mg (95% confidence interval, 52.9–72.9 mg). Eight patients reported pain upon injection, and three were excluded due to severe injection pain and phlebitis.

Conclusions

The estimated ED50 was higher than the predetermined dose based on previous studies. We recommend that the dose of nefopam be chosen after careful consideration of individual variations and clinical settings.

The Antiallodynic Effects of Nefopam Are Mediated by the Adenosine Triphosphate-Sensitive Potassium Channel in a Neuropathic Pain Model

BACKGROUND

Nefopam hydrochloride is a centrally acting compound that induces antinociceptive and antihyperalgesic properties in neuropathic pain models. Previous reports have shown that activation of adenosine triphosphate (ATP)-sensitive and calcium-activated potassium (KATP and KCa2+) channels has antiallodynic effects in neuropathic pain. In the present study, we evaluated the relationship between potassium channels and nefopam to determine whether the antiallodynic effects of nefopam are mediated by potassium channels in a neuropathic pain model.

METHODS

Mechanical allodynia was induced by spinal nerve ligation (SNL) in rats, and the paw withdrawal threshold (PWT) was evaluated by the use of von Frey filaments. Nefopam was administered intraperitoneally before or after SNL. We assessed the relationship between nefopam and intrathecal injection of the KCa2+ channel antagonists apamin and charybdotoxin, and the KATP channel blocker glibenclamide to assess their abilities to reverse the antiallodynic effects of nefopam. In addition, we evaluated whether the KATP channel opener pinacidil had antiallodynic effects and promoted the antiallodynic effects of nefopam.

RESULTS

Administration of nefopam before and after SNL induced significant antiallodynic effects (P < .01, respectively), which were significantly reduced by glibenclamide (P < .01). Pinacidil improved the antiallodynic effects of nefopam (P < .01); however, apamin and charybdotoxin had little effects on the antiallodynic properties of nefopam.

CONCLUSIONS

The antiallodynic effects of nefopam are increased by a KATP channel agonist and reversed by a KATP channel antagonist. These data suggest that the KATP channel is involved in the antiallodynic effects of nefopam in a neuropathic pain model.

A comparison between ketorolac and nefopam as adjuvant analgesics for postoperative patient-controlled analgesia: a randomized, double-blind, prospective study

Background

We compared the analgesic efficacy and side effects of ketorolac and nefopam that were co-administered with fentanyl via intravenous patient-controlled analgesia.

Methods

One hundred and sixty patients scheduled for laparoscopic cholecystectomy were randomly assigned to ketorolac (Group K) or nefopam (Group N) groups. The anesthetic regimen was standardized for all patients. The analgesic solution contained fentanyl 600 µg and ketorolac 180 mg in Group K, and fentanyl 600 µg and nefopam 120 mg in Group N. The total volume of analgesic solution was 120 ml. Postoperative analgesic consumption, recovery of pulmonary function, and pain intensities at rest and during the forced expiration were evaluated at postoperative 2, 6, 24, and 48 h. The postoperative side effects of analgesics were recorded.

Results

Cumulative postoperative analgesic consumptions at postoperative 48 h were comparable (Group K: 93.4 ± 24.0 ml vs. Group N: 92.9 ± 26.1 ml, P = 0.906) between the groups. Pain scores at rest and during deep breathing were similar at the time of each examination. The recovery of pulmonary function showed no significant differences between the groups. Overall, postoperative nausea and vomiting incidence was higher in Group N compared with Group K (59% vs. 34%, P = 0.015). The other side effects were comparable between both groups.

Conclusions

Analgesic efficacies of ketorolac and nefopam that were co-administered with fentanyl for postoperative pain management as adjuvant analgesics were similar. However, postoperative nausea and vomiting incidence was higher in the nefopam-fentanyl combination compared with the ketorolac-fentanyl combination.

Unravelling the binding mechanism and protein stability of human serum albumin while interacting with nefopam analogues: a biophysical and insilico approach

In this study, molecular binding affinity was investigated for Nefopam analogues (NFs), a functionalized benzoxazocine, with human serum albumin (HSA), a major transport protein in the blood. Its binding affinity and concomitant changes in its conformation, binding site and simulations were also studied. Fluorescence data revealed that the fluorescence quenching of HSA upon binding of NFs analogues is based on a static mechanism. The three analogues of NFs binding constants (K_A) are in the order of NF3 > NF2 > NF1 with values of 1.53 ± .057 × 10⁴, 2.16 ± .071 × 10⁴ and 3.6 ± .102 × 10⁵ M^-1, respectively. Concurrently, thermodynamic parameters indicate that the binding process was spontaneous, and the complexes were stabilized mostly by hydrophobic interactions, except for NF2 has one hydrogen bond stabilizes it along with hydrophobic interactions. Circular dichroism (CD) studies revealed that there is a decrease in α-helix with an increase in β-sheets and random coils signifying partial unfolding of the protein upon binding of NFs, which might be due to the formation of NFs-HSA complexes. Further, molecular docking studies showed that NF1, NF2 and NF3 bound to subdomains IIIA, IB and IIA through hydrophobic interactions. However, NF1 have additionally formed a single hydrogen bond with LYS 413. Furthermore, molecular simulations unveiled that NFs binding was in support with the structural perturbation observed in CD, which is evident from the root mean square deviation and R_g fluctuations. We hope our insights will provide ample scope for engineering new drugs based on the resemblances with NFs for enhanced efficacy with HSA.

Opioid sparing effect and safety of nefopam in patient controlled analgesia after laparotomy: A randomized, double blind study

OBJECTIVES

A double-blind randomised study to evaluate the opioid sparing effect and safety of nefopam when administered via intravenous patient controlled analgesia (PCA) with fentanyl.

METHODS

Patients planned for elective open laparotomy, were randomly assigned to receive into fentanyl 25 µg/ml (SF group) or nefopam 2.4 mg/ml plus fentanyl 25 µg/ml (NF group). Patients were assessed before surgery and for 24 h postoperatively.

RESULTS

Total PCA fentanyl consumption was significantly lower in the NF group (n = 35) than the SF group (n = 36). Pain scores were significantly lower and patients' satisfaction with treatment significantly better in the NF group than the SF group. Dry mouth and dizziness were significantly more frequent in the NF group than the SF group. There were no other statistically significant between-group differences in the incidence of adverse events.

CONCLUSIONS

Intravenous PCA using nefopam + fentanyl following laparotomy has an opioid sparing effect and is associated with a low incidence of some of the typical opioid related adverse events.

TRIAL REGISTRY

Clinicaltrials.gov Registration No: NCT02596269.

Preventive Analgesic Efficacy of Nefopam in Acute and Chronic Pain After Breast Cancer Surgery: A Prospective, Double-Blind, and Randomized Trial

Breast cancer surgery is known to cause severe acute postoperative pain, which can persist for a long time. We administered nefopam preventively to patients undergoing lumpectomy with axillary lymph node dissection or sentinel lymph node biopsy, and evaluated its efficacy on acute and chronic postoperative pain.Enrolled patients were assigned to the nefopam (n = 41) or the control (n = 42) group. Before initiating the operation, 20 mg of nefopam was given to the patients of the nefopam group, and normal saline was used in the control group. Ketorolac was given at the end of surgery, and meloxicam was prescribed in the postoperative period to all patients in both groups. Pain was assessed using a numerical rating scale (NRS), and the rescue analgesic drug was given when the NRS was >5. Implementation of postoperative chemotherapy, radiotherapy (RT), or hormone therapy was evaluated.The NRS of postoperative pain was significantly lower in the nefopam than in the control group in the postanesthetic care unit (4.5 ± 2.2 vs 5.7 ± 1.5, respectively; P = 0.01), at postoperative 6 h (3.0 ± 1.6 vs 4.5 ± 1.3, respectively; P < 0.001), and at postoperative 24 h (3.1 ± 1.1 vs 3.8 ± 1.5, respectively; P = 0.01) with reduced use of rescue analgesic drugs. Significantly fewer patients suffered from chronic postoperative pain in the nefopam than in the control group at postoperative 3 months (36.6% vs 59.5%, P = 0.04). Considering only the cohort without postoperative adjuvant RT, the difference in the proportion of patients reporting chronic pain increased (23.5% in the nefopam group vs 61.5% in the control group, P = 0.04).Preventive nefopam was helpful in reducing the acute postoperative pain, with reduced use of rescue analgesic drugs, and it contributed to reduced occurrence of chronic pain at postoperative 3 months after breast cancer surgery.

The Effect of Nefopam on Postoperative Fentanyl Consumption: A Randomized, Double-blind Study

Background

Nefopam is a non-opioid, non-steroidal, centrally acting analgesic drug. The concomitant use of opioids and nefopam is believed to have many advantages over the administration of opioids alone for postoperative pain management. We conducted a randomized, double-blind study to determine the fentanyl-sparing effect of co-administration of nefopam with fentanyl for postoperative pain management via patient controlled analgesia (PCA).

Methods

Ninety female patients who underwent laparoscopic total hysterectomy under general anesthesia were randomized into 3 groups, Group A, fentanyl 1,000 µg; Group B, fentanyl 500 µg + nefopam 200 mg; and Group C, fentanyl 500 µg + nefopam 400 mg, in a total volume of 100 ml PCA to be administered over the first 48 h postoperatively without basal infusion. The primary outcome was total fentanyl consumption during 48 h; secondary outcomes included pain scores and incidence of side effects.

Results

Eighty-one patients were included in the analysis. The overall fentanyl-sparing effects of PCA with concomitant administration of nefopam during the first 48 h postoperatively were 54.5% in Group B and 48.9% group C. Fentanyl use was not significantly different between Groups B and C despite the difference in the nefopam dose. There were no differences among the three groups in terms of PCA-related side effects, although the overall sedation score of Group B was significantly lower than that of Group A.

Conclusions

The concomitant administration of nefopam with fentanyl for postoperative pain management may allow reduction of fentanyl dose, thereby reducing the risk of opioid-related adverse effects.

New modalities of pain treatment after outpatient orthopaedic surgery

Postoperative pain relief is one of the cornerstones of success of orthopaedic surgery. Development of new minimally-invasive surgical procedures, as well as improvements in pharmacological and local and regional techniques should result in optimal postoperative pain control for all patients. The analgesic strategy has to be efficient, with minimal side effects, and be easy to manage at home. Multimodal analgesia allows for a reduction of opiate use and thereby its side effects. Local and regional analgesia is a major component of this multimodal strategy, associated with optimal pain relief, even upon mobilization, and it has beneficial effects on postoperative recovery. Ultrasound guidance improves the success rate of distal nerve blocks and makes distal selective blockade possible, helping to preserve the limb's motility. Besides peripheral nerve blocks, local infiltration (incisional and/or intra-articular) is also important to consider. Duration of the nerve blockade is limited after a single injection. This must be taken into consideration to avoid the recurrence of pain when the patient returns home. Continuous perineural blocks using catheters are an option that can be easily managed at home with monitoring by home-care nurses. Extended-release liposomal bupivacaine and adjuvants such as dexamethasone could significantly enhance the duration of the sensory block, thereby reducing the indications for pain pumps. Non-pharmacological approaches, such as cryotherapy, hypnosis and acupuncture should not be ignored.

Analgesic effects of nefopam in patients undergoing bimaxillary osteotomy: A double-blind, randomized, placebo-controlled study

PURPOSE

Many studies have examined the postoperative analgesic effects of nefopam in various settings. However, although nefopam is expected to be useful in bimaxillary osteotomy, no published data are available.

MATERIAL AND METHODS

We divided 42 patients into nefopam [n = 21, nefopam 20 mg intravenous (i.v.) 30 min before surgery, followed by an i.v. infusion (5 mg/h) beginning immediately postoperatively for 24 h] and control [n = 21, normal saline] groups. Then we compared the analgesic efficacy, side effects, and degree of patient satisfaction with postoperative analgesia.

RESULTS

Pain was lower in the nefopam group than in the controls in the recovery room [4.6 (3.0-6.0) vs. 6.0 (5.5-7.0), median (interquartile range), P = 0.002] and on the ward. Fewer patients in the nefopam group required rescue analgesics, and the degree of patient satisfaction was significantly higher in the nefopam group (P < 0.001). There were no significant differences in other side effects between the groups. However, the control group showed more sedation 1 h postoperatively (P = 0.009).

CONCLUSION

Nefopam is an effective analgesic in bimaxillary osteotomy in that it can reduce the use of opioids and nonsteroidal anti-inflammatory drugs, thereby reducing the side effects of conventional analgesics. (

TRIAL REGISTRATION

ClinicalTrials.gov (NCT 01461031)).

Effect of nefopam- versus fentanyl-based patient-controlled analgesia on postoperative nausea and vomiting in patients undergoing gynecological laparoscopic surgery: a prospective double-blind randomized controlled trial

OBJECTIVE

This study comparatively evaluated the effect of patient-controlled analgesia (PCA) regimens using equipotent doses of nefopam or fentanyl during laparoscopic gynecological surgery on postoperative nausea and vomiting (PONV).

RESEARCH DESIGN AND METHODS

Patients undergoing gynecological laparoscopic surgery were randomly allocated to receive either nefopam- (non-opioid; N group) or fentanyl-based (F group) PCA. PONV and postoperative pain were assessed during the 72 hours following discharge from the post-anesthetic care unit (PACU). The adverse effects of nefopam were also evaluated.

CLINICAL TRIAL REGISTRATION

Cris.nih.go.kr ID KCT0000783.

RESULTS

In total, 94 patients were included in the final analysis. The PONV incidence and scale and the Rhodes index scores were significantly lower in the N group than the F group at all measured times. The N group exhibited a significantly lower incidence of PONV (15/47 [31.9%] vs. 27/47 [57.4%], respectively; P = 0.022) and severity of PONV (0 [1] vs. 1 [2], respectively; P = 0.005) 24 hours after PACU discharge and a significantly lower Rhodes index score (0 [3] vs. 5 [9], respectively; P = 0.002) from 30 minutes after PACU arrival to 24 hours after PACU discharge than did the F group. There was no significant difference in postoperative pain at any time between the two groups. Dry mouth on PACU arrival was significantly more frequent in the N group. However, the frequency of dry mouth decreased after PACU arrival in the N group, resulting in a significantly lower incidence 24 hours after PACU discharge.

CONCLUSIONS

Use of a PCA regimen with nefopam for analgesia was associated with a similar degree of pain control and superior PONV outcomes 24 hours after PACU discharge and no adverse events compared with a PCA regimen using an equipotent dose of fentanyl.

Nefopam as an adjunct to intravenous patient-controlled analgesia after renal transplantation: a randomised trial

BACKGROUND

Nefopam has been used as an adjuvant to opioid analgesia after operation. We investigated the efficacy of nefopam as an adjunct to fentanyl-based intravenous patient-controlled analgesia (IV PCA) on post-operative pain relief in patients undergoing renal transplantation.

METHODS

Ninety-eight patients undergoing elective renal transplantation were randomised into two groups: nefopam or control groups. The former received nefopam (160 mg in 200 ml at a rate of 4 ml/h) whereas the latter received normal saline during the first 48 h after reperfusion of grafted kidney. Pain intensity scores, cumulative dose of fentanyl, and the incidence of adverse events were assessed at 1, 6, 12, 24, and 48 h post-operatively. Serum creatinine and estimated glomerular filtration rate were evaluated on post-operative days 1, 2, 4, and 7.

RESULTS

The cumulative fentanyl consumption during the first 48 h after operation was 19% less in the nefopam group than that in the control group (1005 ± 344 μg vs. 1246 ± 486 μg, mean ± SD; P = 0.006). Pain intensity scores at rest and on coughing were significantly lower in the nefopam group throughout the first 12 and 48 h after operation, respectively. Adverse events and early graft function were comparable between the groups, except a significantly lower incidence of drowsiness observed in the nefopam group (4% vs. 21%, P = 0.027).

CONCLUSION

In combination with fentanyl PCA, nefopam reduced post-operative fentanyl consumption with superior analgesia after renal transplantation.

Parecoxib for the prevention of shivering after general anesthesia

BACKGROUND

Shivering is the most common complication during the recovery period after general anesthesia, and there is no clear consensus about the best strategy for its prophylactic. The aim of the study was to evaluate the efficacy of parecoxib in prevention of postoperative shivering.

METHODS

Eighty patients with American Society of Anesthesiologists physical status I-II, who were scheduled for minor urological surgeries under general anesthesia, were randomly assigned to two groups (n = 40 in each group): group P received 40 mg of parecoxib by intravenous bolus injection and group S received the same volume of normal saline in the same way just after the induction of anesthesia. Hemodynamic parameters and body temperatures including tympanic and axillary temperature were monitored. The occurrence of shivering and pain intensity score were recorded during the recovery period.

RESULTS

Parecoxib significantly reduced the incidence and severity of shivering in comparison with the placebo. Postoperative shivering was observed in 22 patients in group S (55%), compared with nine in group P (22.5%) (P = 0.003). In addition, pain intensity scores were lower in group P during recovery period; consequently, less rescue analgesics were required in group P when compared with group S (P = 0.001). Regarding the body temperature, it was found that core temperature decreased but peripheral temperature increased significantly in both groups. There was no significant difference between groups in all time intervals.

CONCLUSIONS

Prophylactic administration of parecoxib produces dual effects on antishivering and postoperative analgesia. This implies that cyclooxygenase 2-prostaglandin E2 pathways may be involved in the regulation of shivering.

Population pharmacokinetics of nefopam in elderly, with or without renal impairment, and its link to treatment response

AIMS

Nefopam is a nonmorphinic central analgesic, for which no recommendation exists concerning adaptation of regimen in aged patients with or without renal impairment. The objective was to describe the pharmacology of nefopam in aged patients to obtain guidelines for practical use.

METHODS

Elderly patients (n = 48), 65-99 years old, with severe or moderate renal impairment or with normal renal function, were recruited. Nefopam (20 mg) was administered as a 30 min infusion postoperatively. Simultaneously, a 1 min intravenous infusion of iohexol was performed, in order to calculate the glomerular filtration rate. Blood samples were drawn to determine nefopam, desmethyl-nefopam and iohexol plasma concentrations. Nefopam and desmethyl-nefopam concentrations were analysed using a nonlinear mixed-effects modelling approach with Monolix version 4.1.3. The association between pharmacokinetic parameters and treatment response was assessed using logistic regression.

RESULTS

A two-compartment open model was selected to describe the pharmacokinetics of nefopam. The typical population estimates (between-subject variability) for clearance, volume of distribution, intercompartmental clearance and peripheral volume were, respectively, 17.3 l h(-1) (53.2%), 114 l (121%), 80.7 l h(-1) (79%) and 208 l (63.6%). Morphine requirement was related to exposure of nefopam. Tachycardia and postoperative nausea and vomiting were best associated with maximal concentration and the rate of increase in nefopam plasma concentration.

CONCLUSIONS

We identified the nefopam pharmacokinetic predictors for morphine requirement and side-effects, such as tachycardia and postoperative nausea and vomiting. In order to maintain morphine sparing and decrease side-effects following a single dose of nefopam (20 mg), simulations suggest an infusion time of >45 min in elderly patients with or without renal impairment.

A Randomized Clinical Trial of Nefopam versus Ketorolac Combined With Oxycodone in Patient-Controlled Analgesia after Gynecologic Surgery

OBJECTIVES

Nefopam is a centrally-acting non-opioid analgesic, which has no effect on bleeding time and platelet aggregation. There has been no study about nefopam and oxycodone combination for postoperative analgesia. In this study, we present efficacy and side effects of nefopam/oxycodone compared with ketorolac/oxycodone in patient-controlled analgesia (PCA) after gynecologic surgery.

METHODS

120 patients undergoing gynecologic surgery were divided randomly into two groups: Nefopam group treated with oxycodone 1 mg and nefopam 1 mg bolus; and Ketorolac group treated with oxycodone 1 mg and ketorolac 1.5 mg bolus. After the operation, a blinded observer assessed the pain with a numeric rating scale (NRS), infused PCA dose and sedation score at 1, 4, 24, and 48 h, nausea, vomiting, headache, shivering, pruritus and delirium at 6, 24 and 48 h, and satisfaction at 48 h after the operation.

RESULTS

Nefopam group showed less nausea than Ketorolac group within 6 h after the operation. There were no significant differences in demographic data and other complications between both groups. At 48 h after operation, satisfaction and the infused PCA volumes of Nefopam group (34.0± 19.7 ml) showed no significant differences compared to Ketorolac group (30.7± 18.4 ml, P-value= 0.46).

CONCLUSION

Nefopam showed a similar efficacy and lower incidence of nausea within 6 h after the operation to that of ketorolac in PCA. Nefopam may be a useful analgesic drug for the opioid-based PCA after gynecologic surgery. Further evaluation of accurate equivalent dose of nefopam as well as pharmacokinetics of bolus administration is required.

New health care measures: emphasis on better management of postsurgical pain and postoperative nausea and vomiting

Value-based purchasing and the Hospital Consumer Assessment of Healthcare Providers and Systems are tying patient-centric measures to reimbursements. Hospitals should be particularly concerned about management of postoperative pain and control of postoperative nausea and vomiting (PONV), known to adversely impact overall patient satisfaction. Anesthesiologists are likely to be on the frontlines of these transitions. Although postoperative pain is not always effectively managed, clinicians have the pharmacological tools and guidelines for better pain control. Considerable work has been done in PONV to better identify high-risk patients and effective prophylactic agents. Postoperative pain control and preventing PONV are two relatively straightforward ways to respond to new quality metrics. The aim of this review is to raise practitioner awareness of these new quality metrics and provide an overview of the current tools and methods used to improve postoperative pain control and PONV.

Tranexamic acid decreases risk of haematomas but not pain after hip arthroplasty

BACKGROUND

Tranexamic acid decreases total blood loss after total hip arthroplasty (THA). Total blood loss is the sum of external bleeding and bleeding into tissues, i.e., haematomas. Haematomas may cause acute or even chronic postoperative pain.

HYPOTHESIS

Tranexamic acid decreases haematomas, thereby diminishing postoperative pain after THA.

METHODS

In a retrospective matched case-control study, patients receiving tranexamic acid (15 mg/kg, before the incision and again at skin closure) were compared to controls not given tranexamic acid. Matching was on sex, surgeon, and peri-operative analgesics (ketamine, ketoprofen, pregabalin, and nefopam). Standardised protocols were used for anaesthesia, analgesia, and blood sparing. Haematoma volume was computed as the difference between total blood loss (estimated from the erythrocyte counts on days -1 and +5) and measured external blood loss. Patients were monitored from D0 to D7 then interviewed by telephone on D30, D90, and D180. To detect a 30%-decrease in the morphine dose at H24 (criterion 1) and D7 (criterion 2) and a 20% decrease in haematoma volume on D5 (criterion 3), the required numbers of patients were 90, 90, and 77, respectively; therefore, 95 patients were included.

RESULTS

Tranexamic acid decreased haematoma volume by 30% (351±254 mL versus 247±189 mL erythrocytes, P=0.002), had no effect on morphine consumption at H24 (12±11 mg versus 14±12 mg, P=0.346), increased morphine consumption on D7 (26±24 mg versus 35±36 mg, P=0.029), and had no effect on long-term pain.

DISCUSSION

After THA, tranexamic acid decreases haematoma volume without improving analgesia.

LEVEL OF EVIDENCE

3 (case-control study).

Nefopam after total hip arthroplasty: role in multimodal analgesia

BACKGROUND

Multimodal analgesia combining several non-opioid analgesics is recommended for pain control after surgery. In one study of total hip arthroplasty (THA), pain relief achieved by adding ketamine to the paracetamol-ketoprofen combination was statistically significant but remained inadequate in most patients. In two other studies, the analgesic effect of nefopam was synergistic with that of ketoprofen and additive with that of paracetamol. Adding nefopam to the paracetamol-ketoprofen-ketamine combination has not been evaluated.

HYPOTHESIS

Adding nefopam to the paracetamol-ketoprofen-ketamine combination significantly improves analgesia after THA.

MATERIAL AND METHODS

A prospective single-centre comparative non-randomised study (control group then nefopam group) was conducted in patients undergoing THA under general anaesthesia. All patients received paracetamol-ketoprofen-ketamine and morphine/droperidol patient-controlled analgesia. The nefopam group also received a continuous infusion of nefopam (120 mg/d for 48 h). Pain was evaluated daily for 7 days. The main evaluation criteria were morphine consumption, and pain intensity evaluated using a numerical rating scale and a validated questionnaire. To detect a 40% morphine-sparing effect by H24 (α=0.05 and β=0.2), 85 patients were needed in each group.

RESULTS

The two groups (90 patients/group) had no significant differences for perioperative characteristics, pain scores, morphine consumption at H24 (nefopam, 13 ± 12 mg and control, 14 ± 13 mg, P=0.39), or functional recovery. Compared to the control group, the nefopam group had lower rates of nausea/vomiting (P<0.0001), pruritus (P=0.002), and visual disturbances (P=0.02).

DISCUSSION

Nefopam failed to improve pain relief when added to a multimodal analgesia regimen but alleviated several morphine-induced side effects. Redundancy between nefopam and ketamine may explain the absence of greater pain relief. This study emphasises the need for clinical evaluations of every analgesic regimen, as the available data were not sufficient to predict these results.

LEVEL OF EVIDENCE

Level III, case-control study.

Antinociceptive effect of intrathecal nefopam and interaction with morphine in formalin-induced pain of rats

Background

Nefopam, a non-opiate analgesic, has been regarded as a substance that reduces the requirement for morphine, but conflicting results have also been reported. The inhibition of monoamine reuptake is a mechanism of action for the analgesia of nefopam. The spinal cord is an important site for the action of monoamines however, the antinociceptive effect of intrathecal nefopam was not clear. This study was performed to examine the antinociceptive effect of intrathecal (i.t.) nefopam and the pattern of pharmacologic interaction with i.t. morphine in the formalin test.

Methods

Male Sprague-Dawley rats were implanted with an i.t. catheter, and were randomly treated with a vehicle, nefopam, or morphine. Formalin was injected into the hind-paw 10 min. after an i.t. injection of the above experiment drugs. After obtaining antinociceptive ED₅₀ of nefopam and morphine, the mixture of nefopam and morphine was tested for the antinociceptive effect in the formalin test at a dose of 1/8, 1/4, 1/2 of ED₅₀, or ED₅₀ of each drug followed by an isobolographic analysis.

Results

Intrathecal nefopam significantly reduced the flinching responses in both phases of the formalin test in a dose-dependent manner. Its effect, however, peaked at a dose of 30 µg in phase 1 (39.8% of control) and 10 µg during phase 2 (37.6% of control). The isobolograhic analysis indicated an additive interaction of nefopam and morphine during phase 2, and a synergy effect in antinociception during phase 1.

Conclusions

This study demonstrated that i.t. nefopam produces an antinociceptive effect in formalin induced pain behavior during both phases of the formalin test, while interacting differently with i.t. morphine, synergistically during phase 1, and additively during phase 2.

Ondansetron does not attenuate the analgesic efficacy of nefopam

OBJECTIVES

The aim of this study was to investigate if there is any interaction between ondansetron and nefopam when they are continuously co-administrated during patient-controlled intravenous analgesia (PCIA).

METHODS

The study was a prospective, randomized, controlled, non-inferiority clinical trial comparing nefopam-plus-ondansetron to nefopam alone. A total of 230 postoperative patients using nefopam for PCIA, were randomly assigned either to a group receiving continuous infusion of ondansetron (Group O) or to the other group receiving the same volume of normal saline continuously (Group N). Postoperative pain intensity scores, the sum of pain intensity difference over 24 hours postoperatively (SPID24hr), the incidence of adverse events, and the total consumption of nefopam were evaluated respectively.

RESULTS

Postoperative pain was treated successfully in both groups. The mean SPID24hr scores were 95.6 mm in Group N and 109.3mm in Group O [95% confidence interval (CI) -14.28, 24.32]. The lower margin of the 95% CI was above the pre-determined non-inferiority margin (-30mm) for SPID24hr, which indicated that nefopam-plus-ondansetron was not worse than the nefopam alone in term of analgesic efficacy. In addition, there was no statistical difference between the two groups in term of cumulative consumption of nefopam. Compared with Group N, postoperative vomiting was significantly reduced in Group O during the postoperative 24 hours (P < 0.05). Less rescue antiemetics were given to patients in Group O than those receiving nefopam alone (P < 0.05). There were no differences in postoperative nausea between the two groups.

CONCLUSION

Nefopam-plus-ondansetron is not inferior to nefopam alone in relieving the pain in PCIA after minimally invasive surgery. In addition, adverse events are reduced without compromising analgesic efficacy.