Comparison of nefopam and pethidine in postoperative pain

The effect of the addition of nefopam to intraoperative ketoprofen and acetaminophen on postoperative morphine requirements after laparoscopic cholecystectomy: a randomized controlled trial

BACKGROUND

Few studies investigated the use of nefopam for pain control after laparoscopic cholecystectomy in the context of multimodal analgesia. The aim of this study was to evaluate the effect of adding nefopam to ketoprofen and acetaminophen given before the end of laparoscopic cholecystectomy.

METHODS

In this double-blind, controlled study, 90 patients undergoing laparoscopic cholecystectomy during sevoflurane-dexmedetomidine-based anesthesia were randomized to receive either ketoprofen and acetaminophen or nefopam, ketoprofen, and acetaminophen for postoperative pain control before the end of surgery. The primary outcome was total morphine consumption in the Postanesthesia Care Unit (PACU).

RESULTS

PACU morphine consumption was significantly lower in the experimental group compared to the control group (0.9±1.8 mg vs. 2.3±2.4 mg, respectively; P=0.004, Cohen's d=0.63). In the experimental group, a smaller proportion of patients received morphine in PACU (24% vs. 60%, respectively; P=0.001), morphine during the first 24 hours after surgery (47% vs. 77%, respectively; P=0.004), and acetaminophen on the floor (76% vs. 93%, respectively; P=0.039) compared with the control group. The average pain score during PACU stay was also significantly lower in the experimental group (1.7±2.0 vs. 2.7±2.0, P=0.01). Median time to first morphine requirement (44.0 minutes, 95% CI [(31.96 to, 52.21)] was shorter in the control group than in the experimental group (higher than the 90 minutes-last time point taken in PACU).

CONCLUSIONS

Adding nefopam to ketoprofen and acetaminophen before the end of laparoscopic cholecystectomy provides a reduction in morphine consumption with superior analgesia in PACU.

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.

Post-operative intravenous patient-controlled analgesic efficacy of morphine with ketorolac versus nefopam after laparoscopic gynecologic surgery: a randomized non-inferiority trial

Background

Nefopam is a non-opioid non-steroidal centrally acting analgesic. This study was conducted to assess the analgesic efficacy of intravenous patient-controlled analgesia (IV-PCA) using nefopam alone, compared with a combination of morphine and ketorolac, after laparoscopic gynecologic surgery.

Methods

Sixty patients undergoing laparoscopic gynecologic surgery received IV-PCA. Group A (n = 30) received IV-PCA with a combination of morphine 60 mg and ketorolac 180 mg, while group B (n = 30) received nefopam 200 mg (basal rate 1 ml/h, bolus 1 ml, and lockout time 15 min for both). The primary outcome evaluated was analgesic efficacy using the visual analogue scale (VAS). Other evaluated outcomes included the incidence rate of postoperative nausea and vomiting (PONV), patient satisfaction of pain control, percentage of patients requiring additional opioids, and incidence rate of postoperative adverse effects.

Results

Group B was not inferior to group A in relation to the VAS in the post-anesthesia care unit, and at 12, 24, and 48 h after surgery (mean difference [95% confidence interval], 0.50 [–0.43 to 1.43], -0.30 [-1.25 to 0.65], -0.05 [-0.65 to 0.55], and 0.10 [-0.55 to 0.75], respectively). The incidence rate of nausea was lower in group B than in group A at 12 and 24 h after surgery (P = 0.004 and P = 0.017, respectively). There were no significant differences in the other outcomes between groups.

Conclusions

IV-PCA using nefopam alone has a non-inferior analgesic efficacy and produces a lower incidence of PONV in comparison with IV-PCA using a combination of morphine and ketorolac after laparoscopic gynecologic surgery.

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)).

The analgesic effect of nefopam with fentanyl at the end of laparoscopic cholecystectomy

BACKGROUND

Nefopam is a centrally acting analgesic that is used to control pain. The aim of this study was to find an appropriate dose of nefopam that demonstrates an analgesic effect when administered in continuous infusion with fentanyl at the end of laparoscopic cholecystectomy.

METHODS

Ninety patients scheduled for laparoscopic cholecystectomy were randomly assigned to receive analgesia with fentanyl alone (50 µg, Group 1, n = 30), or with fentanyl in combination with nefopam 20 mg (Group 2, n = 30) or in combination with nefopam 40 mg (Group 3, n = 30) at the end of surgery. Pain and side effects were evaluated at 10 minutes, 30 minutes, 1 hour, 2 hours, 6 hours, and 12 hours after arrival in the post-anesthesia care unit (PACU).

RESULTS

Pain was statistically significantly lower in Groups 2 and 3 than in Group 1 at 10 minutes, 2 hours, and 6 hours after arrival in the PACU. Nausea was statistically significantly lower in Group 2 than in Groups 1 and 3 at 10 minutes after arrival in the PACU. Shivering was statistically significantly lower in Groups 2 and 3 than in Group 1 at 10 minutes after arrival in the PACU.

CONCLUSIONS

Nefopam is a drug that can be safely used as an analgesic after surgery, and its side effects can be reduced when fentanyl 50 µg is injected with nefopam 20 mg.

Single dose oral nefopam for acute postoperative pain in adults

BACKGROUND

Nefopam is a centrally-acting but non-opioid analgesic drug of the benzoxazocine chemical class, developed in the early 1970s. It is widely used, mainly in European countries, for the relief of moderate to severe pain as an alternative to opioid analgesic drugs, and used in rheumatic disease and other musculoskeletal disorders in the UK. This review sought to evaluate the efficacy and safety of oral nefopam in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral nefopam in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched CENTRAL (Issue 2, 2009), MEDLINE (1966 to May 2009); EMBASE via Ovid (1980 to May 2009); the Oxford Pain Relief Database (1950 to 1994); and reference lists of studies found.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral nefopam for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The area under the "pain relief versus time" curve was used to derive the proportion of participants with nefopam and placebo experiencing least 50% pain relief over 4 to 6 hours, using validated equations. The number-needed-to-treat-to-benefit (NNT) was calculated using 95% confidence intervals (CIs). The proportion of participants using rescue analgesia over a specified time period, and time to use of rescue analgesia, were sought as additional measures of efficacy. Information on adverse events and withdrawals was also collected.

MAIN RESULTS

No included studies were identified after examining in detail thirteen studies on oral nefopam in participants with established postoperative pain.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral nefopam in acute postoperative pain, its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies are lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes, there is no urgent research agenda.

Effective dose of nefopam in 80% of patients (ED80): a study using the continual reassessment method

AIMS

The effective dose in 50% of patients (ED(50)) is far from being relevant for clinical purposes. We used the continual reassessment method (CRM) to determine the effective dose of nefopam in 80% of the patients suffering from moderate pain in the postoperative period (ED(80)).

METHODS

Patients with a pain intensity >3 on a 1-10 numerical pain score (NPS) received increasing or decreasing doses of nefopam (20, 30, 40, 60, 80 mg) postoperatively. The criterion of success was a NPS <or=3, 30 min after the beginning of infusion. The initial dose was 20 mg and the subsequent doses were determined by the continuous reassessment method (CRM). The data were also fitted a posteriori with the maximum likelihood technique.

RESULTS

Twenty-four patients were enrolled. Nefopam 60 mg gave a probability of success of 0.818 (95% credibility interval 0.606-0.941). Using the maximum likelihood technique, we determined an ED(50) of 27.3 mg and a dose leading to a probability of 0.8 (ED(80)) of 74.4 mg. We did not observe a high incidence of side-effects.

CONCLUSIONS

The ED(80) of nefopam, close to 60 mg is higher than the usual dose of 20 mg. The CRM allowed us to determine the ED(80) of nefopam with reasonable accuracy in a small number of patients as compared with the classical dose-probability curve fitting. We did not observe an increased incidence of side-effects when compared with the literature or to our previous studies.

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

BACKGROUND

Balanced postoperative analgesia combines non-narcotic drugs and opioids. We organized a large study to evaluate nefopam analgesia and tolerance in combination with morphine for patient-controlled analgesia (PCA) after orthopaedic surgery.

METHODS

Two hundred and one patients scheduled to undergo hip arthroplasty were included in this multicentre (n=24), double-blind, randomized study comparing nefopam (20 mg every 4 h for 24 h) with placebo, the first dose being infused peroperatively. The primary outcome measure was the cumulative morphine dose received postoperatively by PCA over 24 h. Secondary outcome measures were the amount of morphine received as a loading dose in the postanaesthesia care unit (PACU) and during the 24-h observation period, and pain assessments using a visual analogue scale (VAS) and a verbal pain scale (VPS), patient's satisfaction with analgesia and treatment tolerance.

RESULTS

The two groups were comparable with respect to their characteristics and preoperative pain assessment. PCA-administered morphine over 24 h was significantly less for the nefopam group than the control group (21.2 (15.3) and 27.3 (19.2) mg respectively; P=0.02). This morphine-sparing effect was greater (35.1%) for patients with severe preoperative pain (VAS>30/100). For the entire study period (loading dose and PCA), morphine use was less for the nefopam group (34.5 (19.6) vs 42.7 (23.6) mg; P=0.01). Pain VAS at PACU arrival and during the whole PACU period was significantly lower for the nefopam than for the placebo group (P=0.002 and 0.04 respectively). Patient satisfaction was similar for the nefopam and placebo groups.

CONCLUSION

In combination with PCA morphine, nefopam gives significant morphine-sparing with lower immediate postoperative pain scores without major side-effects. This analgesic effect seems to be particularly notable for patients with intense preoperative pain.

Postoperative analgesics for superficial surgery. Comparison of four analgesics

The efficacy of mild analgesics after 160 various superficial operations was studied by comparing intravenous lysine-acetylsalicylate (LAS) 1.8 g, Litalgin 4 ml (metamizole = dipyrone 2.0 g+ pitophenone 8.0 mg) or paracetamol 0.5 g to oxycodone 4 mg. At 15 min postdrug, oxycodone 4 mg had the best peak effect but this significant (P less than 0.05) difference to mild analgesics disappeared at 30 min, and thereafter all test analgesics showed an equally low effect. Two-thirds of the patients anaesthetized without peroperative analgesics needed pain relief when recovering from superficial surgery. The need for pain relief was lowest after varicose vein operations 40% of the patients as compared to about 70% after other types of superficial surgery. In 42% of the patients requiring pain relief, the test analgesics alone gave sufficient pain relief. The rest needed an additional 5 mg of oxycodone, on average, to be comfortable. The combined use of mild analgesics and oxycodone for adequate pain relief did not seem to reduce the postdrug sedation as compared to oxycodone alone. The results indicate that in traditional clinical dosages LAS, dipyrone or paracetamol can substitute about 5 mg oxycodone but offer sufficient analgesia only in about 40% of the patients recovering from superficial surgery.

Quantitative determination of nefopam in human plasma, saliva and cerebrospinal fluid by gas-liquid chromatography using a nitrogen-selective detector

A sensitive and selective gas-liquid chromatographic method for the determination of nefopam in human plasma, saliva and cerebrospinal fluid has been developed. The method includes the selective extraction of nefopam and the internal standard, orphenadrine, from biological fluids by a double extraction procedure. The extracted nefopam and internal standard are analyzed by a gas chromatograph equipped with a 3% OV-17 glass column and a nitrogen-phosphorus flame ionization detector (NPFID) operated in the nitrogen mode. The detector provides the needed high sensitivity and also selectivity due to the inherent characteristics of NPFID to discriminate against non-nitrogen containing materials. Five nanograms nefopam per ml plasma or saliva are routinely quantitated with a 1-ml sample or as little as 2 ng per ml cerebrospinal fluid with a 3-ml sample. The intra-day reproducibilities, expressed as the relative standard deviation, are 5, 2 and 3% at 10, 35 and 75 ng/ml plasma levels, respectively. The accuracies expressed by relative error at these levels are 12, -4 and -2%, respectively. The inter-day reproducibility is demonstrated by the small relative standard, deviation, 2%, of the slopes from ten plasma standard curves run on ten different days. In various clinical studies in humans the method has been successfully applied to the study of single-dose pharmacokinetics of nefopam and the monitoring of nefopam concentrations in saliva and cerebrospinal fluids.

Spinal and Supraspinal sites for morphine and nefopam analgesia in the mouse

Using the tail-flick and hot-plate assays, morphine and nefopam were tested for analgesic activity following intraperitoneal (i.p.), intracranial (i.c.) and intraspinal (i.s.) injection in mice. By the i.p. route, morphine was equipotent on both analgesic tests. Nefopam was one-third as potent as morphine on the hot-plate test, but did not affect the tail-flick. Intracranial morphine was more effective on the hot-plate than on the tail-flick, but i.s. morphine was most potent on the tail-flick. Naloxone, 0.5 mg/kg i.p., totally reversed morphine's effects on the tail-flick, but only partially reversed these actions on the hot-plate, suggesting the possibility that morphine's effects on the mouse hot-plate test may be mediated via multiple receptor types. Nefopam was more potent by the i.c. route than by the i.p. route, but its was inactive spinally. Nefopam analgesia was unaffected by naloxone treatment. It is concluded that nefopam is a novel, centrally acting, non-narcotic analgesic.

The effects of nefopam on blood acid-base status in the rabbit: interactions with morphine in the mouse and rabbit

Nefopam, a non-narcotic analgesic, had only minor effects upon the blood pH, PCO2 and standard bicarbonate of the conscious rabbit. In contrast morphine caused a dose-dependent increase in PCO2 and standard bicarbonate. When nefopam was administered in conjunction with morphine (2.5 mg kg-1 and 1 mg kg-1 i.v. respectively) the increase in PCO2 was greater than with morphine alone. Nefopam also increased the antinociceptive and respiratory frequency depressant effects of morphine in the mouse.

Mild analgesics in postoperative pain

1 The intensity of postoperative pain is influenced by many factors, for example, individual variation, site of incision and type of operation, anaesthetic technique, and the interval from the end of operation to the appearance of pain. 2 These factors affect the efficacy of analgesics. 3 Mild analgesics provide adequate pain relief in half of our patients in the immediate postoperative phase when the pain is slight to moderate. 4 The maximum effect of mild analgesics corresponds to that produced by morphine 6-10 mg. Adequate analgesia may not therefore be provided for the treatment of severe postoperative pain unless narcotic analgesics have been used peroperatively. 5 When mild analgesics are combined with narcotics synergism is achieved. 6 As postoperative pain decreases with time, mild analgesics usually provide adequate pain relief on the first and following postoperative days.

Comparison of the analgesic dose-effect relationships of nefopam and oxycodone in postoperative pain

The analgesic dose-effect relationship of nefopam was compared in a double-blind randomised trial with that of oxycodone in immediate postoperative pain. Nefopam 15 mg or oxycodone 4 mg was given every 10 min i.v. (maximum six times) to patients in pain after upper abdominal surgery until their wound pain (scored 0-3) disappeared. The mean pain intensity (PI), initially 2.2 in both groups, descreased by approximately the same extent for up to two doses in both groups (to 1.5 after nefopam 30 mg and to 1.1 after oxycodone 8 mg). Thereafter PI was significantly less in the oxycodone group and diminished almost linearily to 0.1 after the sixth dose (24 mg). In the nefopam group, the PI score fell to 1.1 after the fourth dose (60 mg). This seemed to be the "ceiling" effect since additional doses up to 90 mg did not result in greater pain relief. In the oxycodone group, only two patients (12%) needed maximal dosage (6 x 4 mg), one of them requiring 32 mg of oxycodone. In the nefopam group, 12 patients (75%) needed further pain relief after the maximal dosage (6 x 15 mg). In these patients, oxycodone (maximally 16 mg) gave satisfactory analgesia. Drowsiness and a decrease in the respiratory rate were the principal side-effects of oxycodone, whereas tachycardia, restlessness, sweating and nausea were more frequent after nefopam.