The effect of gabapentin on post-operative pain following tonsillectomy in adults

Comparing the Effects of Pregabalin and Clonidine on Postoperative Pain in Tonsillectomy: A Randomized, Double-Blind, Prospective Clinical Trial

BACKGROUND

Tonsillectomy is one of the most common surgical procedures. This study compared the effect of Pregabalin and Clonidine on postoperative pain in adult patients undergoing elective tonsillectomy.

METHODS

This randomized, double-blind, prospective clinical trial was conducted among 92 patients aged 20 to 50. The clonidine group (C) was given 150 µg of clonidine tablet 90 minutes before surgery, and the pregabalin group (P) was given 300 mg of pregabalin tablet 90 minutes before surgery. The results were analyzed by SPSS 25, and statistical analysis consisted of chisquare, T-test, and χ2 tests, and a p-value less than 0.05 was considered significant.

RESULTS

The mean pain score and analgesic consumption scores in the pregabalin group were lower than in the clonidine group. According to the t-test, there was a significant difference between the two groups regarding pain score and analgesic consumption (p <0.05). Hemodynamic variation in both groups had no significant differences (p >0.05).

CONCLUSION

The present study showed that pregabalin reduced postoperative pain and analgesic consumption more effectively than clonidine.

Residual Symptoms After Carpal Tunnel Decompression and Treatment With Gabapentin: A Multicenter Study

Objectives

To identify postoperative residual symptoms of carpal tunnel syndrome (CTS) and to investigate the effectiveness of gabapentin in the treatment of residual symptoms.

Materials and methods

Of a total of 412 patients who underwent surgery for CTS in four centers over a four-year period, 14 who had residual symptoms after CTS release and did not receive gabapentin (Group A) and 14 patients with postoperative residual symptoms and received gabapentin were included in this retrospective study. Postoperative residual symptoms were defined as persistent nocturnal numbness and tingling with or without occasional daytime pain. Tinel’s and Phalen’s tests were performed for the diagnosis of residual symptoms. Functional Severity Score (FSS), Symptom Severity Score (SSS), and Visual Analog Scale (VAS) were used to evaluate functional outcomes, severity of symptoms, and numbness and sleep quality, respectively at six and 12 weeks postoperatively.

Level of Evidence: III, therapeutic study

Results

There was no statistically significant difference in the mean postoperative FSS (p=0.845) and VAS-numbness scores (p=0.367) between the groups. However, there was a statistically significant difference in the mean postoperative SSS (p=0.025) and VAS-sleep quality scores (p<0.001) between the groups.

Conclusion

Gabapentin treatment can be a treatment of choice for residual symptoms after CTS surgery and clinical improvement can be achieved owing to its relieving effect, particularly in nocturnal symptoms of patients having neuropathic pain.

Effects of Gabapentin Suspension and Rectal Acetaminophen on Postoperative Pain of Adenotonsillectomy in Children

Introduction

Adenotonsillectomy is the main treatment for symptomatic tonsillar hypertrophy with postoperative pain as the most common associated complication. The present study aimed to compare the efficacy of gabapentin with that reported for acetaminophen on the postoperative pain of adenotonsillectomy in children.

Materials and Methods

In this double-blind clinical trial, a total of 60 children within the age range of 7-15 years undergoing adenotonsillectomy were randomly allocated to two groups of gabapentin (n=30) and acetaminophen (n=30). The first group received a 10 mg/kg dose of gabapentin suspension preoperatively and placebo (suppository) after the intubation. The second group received a 40 mg/kg dose of acetaminophen suppository and placebo suspension simultaneous with that in the case group. Using the pain scale (based on the score of visual analog scale, prescribed drugs, dosage as well as incidence of postoperative nausea and vomiting were recorded 0, 2, 4, 6, 12, and 24 h after the surgery. The data were analyzed using SPSS software (version 22.0). A p-value less than 0.05 was considered statistically significant.

Results

There was no significant difference between the two groups considering the pain scores at 0, 2, 4, 6, 12, and 24 h after the surgery. In addition, the trend of pain intensity statistically decreased within 0 to 24 h in both acetaminophen (P<0.001) and gabapentin (P<0.001) groups. No statistically significant difference was observed between the two groups regarding the postoperative incidence of nausea and vomiting.

Conclusion

The obtained results of the present study showed that the administration of gabapentin and acetaminophen significantly reduced the postoperative pain of tonsillectomy and need for narcotics in these patients after the surgery. However, in this study, there was no particular reported superiority for any of the two groups in terms of the effects of gabapentin suspension and rectal acetaminophen.

A preliminary report on the effect of gabapentin pretreatment on periprocedural pain during in-office posterior nasal nerve cryoablation

BACKGROUND

Posterior nasal nerve (PNN) cryoablation is a novel surgical technique to address allergic and nonallergic rhinitis. Periprocedural pain has been reported after PNN cryoablation and there are no standardized protocols for optimal in-office local anesthesia. This study sought to evaluate the effect of gabapentin on patient discomfort following in-office PNN cryoablation.

METHODS

Multi-institutional prospective analysis of patients undergoing in-office PNN cryoablation for allergic or nonallergic rhinitis between March 2018 and April 2019. Patients received local anesthesia with or without 600 mg oral gabapentin 1 hour preprocedure. Rhinitis diagnosis, demographics, and baseline disease-specific quality of life (mini-Rhinoconjunctivitis Quality of Life Questionnaire [RQLQ] and Total Nasal Symptom Score [TNSS]) were recorded. Patient discomfort was measured by the pain visual analogue scale (VAS) posttreatment and rated 0 to 10 on an ordinal scale. Fisher's exact and Wilcoxon 2-sample tests were used to evaluate differences between the 2 groups.

RESULTS

A total of 26 patients were enrolled (gabapentin n = 15, control = 11). Baseline TNSS scores in the gabapentin vs control group were median [25th percentile to 75th percentile]) 10 (7.5 to 11.0) and 9 (6.0 to 10.0) (p = 0.35). Baseline Mini-RQLQ scores in gabapentin vs control groups were 3.21 (2.0 to 4.0) and 2.92 (2.78 to 4.35) (p = 0.51). The median VAS pain scores at 5, 20, and 30 minutes in the gabapentin vs control group were 0.0 (0.0 to 2.0) vs 3.0 (1.0 to 4.0), 2.0 (0.0 to 3.0) vs 8.0 (6.0 to 10.0), and 1.0 (0.0 to 1.0) vs 5.0 (4.0 to 6.0) (p = 0.02, p = 0.0043, and p = 0.003, respectively).

CONCLUSION

Preprocedure gabapentin significantly reduces immediate and delayed postprocedural patient discomfort following PNN cryoablation.

Effect of Perioperative Gabapentin Use on Postsurgical Pain in Patients Undergoing Head and Neck Mucosal Surgery: A Randomized Clinical Trial

Importance

Effective postoperative pain management increases patient satisfaction, reduces cost, reduces morbidity, and shortens hospitalizations. Previous studies investigating multimodal pain therapy in otolaryngology patients focused on homogenous patient groups with short postoperative follow-up times.

Objective

To investigate the effect of perioperative gabapentin treatment on postsurgical pain in patients undergoing head and neck mucosal surgery.

Design, Setting, and Participants

Adults undergoing head and neck mucosal surgery from July 25, 2016, through June 19, 2017, were included in this double-blinded, placebo-controlled randomized clinical trial and randomized to receive gabapentin, 300 mg twice daily, or placebo before surgery and up to 72 hours after surgery.

Main Outcomes and Measures

Primary outcome was hourly narcotic use calculated in morphine equivalents. Secondary outcomes included subjective visual analog scale pain scores captured for resting, coughing, and swallowing using a 0- to 100-mm scale (a 100-mm line anchored with no pain on the left end and worst possible pain on the right end). A change of 10 mm or more was deemed to be clinically meaningful. Additional secondary outcome measures included degree of pain control, patient satisfaction, and adverse effects.

Results

Of the 110 patients randomized to receive gabapentin or placebo, 11 and 10 withdrew from each group, respectively. Ninety patients were then analyzed: 44 in the gabapentin group (mean [SD] age, 61.1 [10.0] years; 33 [75%] male; 40 [91%] white) and 46 in the placebo group (mean [SD] age, 60.9 [11.3] years; 35 [78%] male; 43 [94%] white). Both groups had similar self-reported levels of preoperative pain and narcotic effectiveness. A median difference of 0.26 mg/h of morphine (95% CI, -0.27 to 0.94 mg/h) was found between groups. After controlling for comorbidity and self-reported baseline pain levels, mixed model analysis found the difference in marginal means of visual analog scale scores between groups to be lower in the gabapentin group compared with the placebo group for all categories (rest difference, 7.9 mm; 95% CI, -0.4 to 16.2 mm; cough difference, 8.9 mm; 95% CI, -0.5 to 18.3 mm; swallow difference, 9.4 mm; 95% CI, -1.2 to 20.0 mm). More patients in the gabapentin group reported that pain was always well controlled than in the placebo group (difference, 9.2%; 95% CI, -21% to 3%). Gabapentin and placebo groups reported similar levels of satisfaction with pain control (difference, 2%; 95% CI, -11% to 15%). There was no clinically meaningful difference in reported nausea between the 2 groups (difference, 6%; 95% CI, -14% to 26%).

Conclusion and Relevance

Perioperative gabapentin given 300 mg twice daily did not result in reduced narcotic use, but results were compatible with clinically meaningful reductions in pain scores. Satisfaction with pain control and adverse effects were similar between groups.

Trial Registration

ClinicalTrials.gov Identifier: NCT02926573.

Systematic review of analgesics and dexamethasone for post-tonsillectomy pain in adults

BACKGROUND

Intense pain can last several days after tonsillectomy. It is often undertreated and improved analgesic strategies that can be safely used at home are needed.

METHODS

We conducted a systematic review and meta-analysis on the effectiveness of systemic medications used for post-tonsillectomy pain in adult and adolescent (13 yr old) patients. Studies were identified from PubMed, the Cochrane Library, and by hand searching reference lists from studies and review articles. Randomised, double-blind, placebo-controlled studies reporting on pain intensity or use of rescue analgesia were included.

RESULTS

Twenty-nine randomised controlled trials representing 1816 subjects met the inclusion criteria. Follow-up time was ≤24 h in 15 studies, in which the majority were taking nonsteroidal anti-inflammatory drugs. Thirteen studies were suitable for meta-analysis. In pooled analysis, paracetamol, dexamethasone, and gabapentinoids reduced pain intensity on the day of operation. In individual studies, ketoprofen, ibuprofen, lornoxicam, parecoxib, rofecoxib, indomethacin and dextromethorphan reduced pain intensity, need for rescue analgesics, or both on the day of operation. Oral celecoxib for 2 postoperative weeks or i.v. ketamine on the day of operation were not effective at the studied doses. Dexamethasone in multiple doses provided analgesia beyond 1 postoperative day. Pain was moderate to strong in both study and control groups during the first postoperative week.

CONCLUSIONS

Single analgesics and dexamethasone provide only a weak to moderate effect for post-tonsillectomy pain on the day of operation and thus a multimodal analgesic strategy is recommended. Short follow-up times and clinical heterogeneity of studies limit the usefulness of results.

Gabapentin completely neutralized the acute morphine activation in the rat hypothalamus: a c-Fos study

Aim: The molecular mechanism of gabapentin (GBP)–morphine combinational function and its neuro-anatomical sites of action to prevent, to neutralize morphine side effects and also the enhancement its analgesic effect of morphine is unknown. Methods: Morphine (10 mg/kg), saline, co-injection: GBP (150 mg/kg) with morphine (10 mg/kg) were injected by intraperitoneal injection in rats under deep anaesthesia. C-Fos immunohistochemistry technique was used to locate c-Fos expression in rat hypothalamus. Results: Gabapentin in combination with morphine significantly (p < 0.01) attenuated the acute morphine induced c-Fos immunoreactive neuron in hypothalamus. Conclusion: GBP neutralized the morphine sensitization in rat hypothalamus. GBP might neuromodulate and or antagonize the receptor regulatory machinery of morphine sensitization circuit which might work for drug discovery of morphine abuse.

The effect of flurbiprofen oral spray and ibuprofen vs ibuprofen alone on postoperative tonsillectomy pain: An open, randomised, controlled trial

OBJECTIVE

This prospective clinical study was carried out to evaluate the analgesic efficacy and safety of oral spray form of flurbiprofen in the treatment of postoperative pain in tonsillectomy patients.

STUDY DESIGN

Open, randomised, controlled clinical study.

SETTING

Tertiary care training and research hospital.

PARTICIPANTS

One hundred (53 males, 47 females) with an age range of 18-53 years old (mean 27.4 ± 9.3 SD) undergoing tonsillectomy were enrolled in this prospective controlled study.

MAIN OUTCOME MEASURES

Patients receiving oral ibuprofen and flurbiprofen as spray form were enrolled as study group (53), whereas patients receiving only oral ibuprofen were enrolled as control group (47) in postoperative period. Postoperative pain was evaluated through visual analogue scale on 12th hour, first, third and seventh days after surgery.

RESULTS

The mean maximal pain score of patients who have received flurbiprofen spray and ibuprofen was 3.36 ± 1.93 SD that was statistically lower than the mean maximal pain score of patients who were medicated with only ibuprofen which was 4.06 ± 1.29 SD on postoperative seventh day (P = .013).

CONCLUSION

This study revealed that addition of flurbiprofen spray to oral ibuprofen is effective in the management of postoperative pain in tonsillectomy patients with no notable complications.

Dose-related beneficial and harmful effects of gabapentin in postoperative pain management - post hoc analyses from a systematic review with meta-analyses and trial sequential analyses

Background

During the last 15 years, gabapentin has become an established component of postoperative pain treatment. Gabapentin has been employed in a wide range of doses, but little is known about the optimal dose, providing the best balance between benefit and harm. This systematic review with meta-analyses aimed to explore the beneficial and harmful effects of various doses of gabapentin administered to surgical patients.

Materials and methods

Data in this paper were derived from an original review, and the subgroup analyses were predefined in an International Prospective Register of Systematic Reviews published protocol: PROSPERO (ID: CRD42013006538). The methods followed Cochrane guidelines. The Cochrane Library’s CENTRAL, PubMed, EMBASE, Science Citation Index Expanded, Google Scholar, and FDA database were searched for relevant trials. Randomized clinical trials comparing gabapentin versus placebo were included. Four different dose intervals were investigated: 0–350, 351–700, 701–1050, and >1050 mg. Primary co-outcomes were 24-hour morphine consumption and serious adverse events (SAEs), with emphasis put on trials with low risk of bias.

Results

One hundred and twenty-two randomized clinical trials, with 8466 patients, were included. Sixteen were overall low risk of bias. No consistent increase in morphine-sparing effect was observed with increasing doses of gabapentin from the trials with low risk of bias. Analyzing all trials, the smallest and the highest dose subgroups demonstrated numerically the most prominent reduction in morphine consumption. Twenty-seven trials reported 72 SAEs, of which 83% were reported in the >1050 mg subgroup. No systematic increase in SAEs was observed with increasing doses of gabapentin.

Conclusion

Data were sparse, and the small number of trials with low risk of bias is a major limitation for firm conclusions. Taking these limitations into account, we were not able to demonstrate a clear relationship between the dosage of gabapentin and opioid-sparing or harmful effects. These subgroup analyses are exploratory and hypothesis-generating for future trialists.

Longitudinal Perioperative Pain Assessment in Head and Neck Cancer Surgery

Objective:

To evaluate perioperative pain in patients undergoing major head and neck cancer surgery and identify associations between preoperative and postoperative pain characteristics.

Methods:

Patients undergoing head and neck surgery with regional/free tissue transfer were enrolled. Preoperative pain and validated screens for symptoms (neuropathic pain, anxiety, depression, fibromyalgia) were assessed. Postoperatively, patients completed a pain diary for 4 weeks.

Results:

Twenty-seven patients were enrolled. Seventy-eight percent had pain prior to surgery, and for 38%, the pain had neuropathic characteristics. Thirteen patients (48%) completed at least 2 weeks of the postoperative pain diary. Patients with moderate/severe preoperative pain report significantly greater pain scores postoperatively, though daily pain decreased at a similar linear rate for all patients. Patients with more severe preoperative pain consumed greater amounts of opioids postoperatively, and this correlated with daily postoperative pain scores. Patients who screened positive for neuropathic pain also reported worse postoperative pain.

Conclusion:

Longitudinal perioperative pain assessment in head and neck patients undergoing surgery suggests that patients with worse preoperative pain continue to endorse worse pain postoperatively and require more narcotics. Patients with preoperative neuropathic pain also report poor pain control postoperatively, suggesting an opportunity to identify these patients and intervene with empiric neuropathic pain treatment.

Gabapentin in the Management of Pain following Tonsillectomy: A Randomized Double-Blind Placebo-Controlled Trial

Objective To determine if a single dose of oral gabapentin given prior to tonsillectomy decreases postoperative morbidity. Study Design Prospective randomized double-blind placebo-controlled trial. Setting Southern District Health Board University Hospitals, New Zealand, over a 10-month period. Subjects and Methods Seventy-three adults undergoing tonsillectomy were randomized to receive either a single preoperative dose of oral gabapentin (600 mg) or placebo. A standard analgesic protocol was prescribed for 14 postoperative days. The primary outcome was a patient-assigned visual analog scale pain score during rest and swallow; secondary outcomes were analgesic consumption, nausea, vomiting, and return to normal diet and activities. Complications and adverse effects were also recorded. Results Thirty-seven participants were allocated to the placebo group and 36 to the gabapentin group. After withdrawals, data were analyzed from 31 in the placebo group and 27 in the gabapentin group. Pain scores between groups were not significantly different within the first 6 hours. The gabapentin group recorded significantly higher pain scores between days 5 and 10 (maximal difference, day 8: 17.6 mm; effect size, -8.87; P = .03; 95% CI, -16.883 to -0.865). There was no significant difference in swallow pain scores or early postoperative fentanyl consumption. Consumption of paracetamol ( P = .01 at day 13 and P = .004 at day 14) and codeine ( P < .05 at days 3-5, 7, 8, 10, 14) was higher in the gabapentin group. No significant difference between groups was found for the other outcomes. Conclusions Preemptive gabapentin (600 mg) was associated with greater postoperative pain scores and analgesic consumption following adult tonsillectomy when compared with placebo.

Gabapentin for post-operative pain management - a systematic review with meta-analyses and trial sequential analyses

BACKGROUND

Perioperative pain treatment often consist of combinations of non-opioid and opioid analgesics, 'multimodal analgesia', in which gabapentin is currently used. The aim was to document beneficial and harmful effects of perioperative gabapentin treatment.

METHODS

Randomized clinical trials comparing gabapentin vs. placebo or active placebo in adult surgical patients receiving gabapentin perioperatively were included. This review was conducted using Cochrane standards, trial sequential analysis (TSA), and Grading of Recommendations Assessment, Development, and Evaluation (GRADE). The primary outcomes were 24-h opioid consumption and incidence of serious adverse events (SAE).

RESULTS

One hundred and thirty-two trials with 9498 patients were included. Thirteen trials with low risk of bias reported a reduction in 24-h opioid consumption of 3.1 mg [0.5, 5.6] [corrected]. In the analysis of gabapentin as add-on analgesic to another non-opioid analgesic regimen found a mean reduction in 24-h morphine consumption of 1.2 mg [-0.3, 2.6; TSA-adjusted CI: -0.3, 2.6] in trials with low risk of bias. [corrected]. Nine trials with low risk of bias reported a risk ratio of SAEs of 1.61 [0.91; 2.86; TSA-adjusted CI: 0.57, 4.57].

CONCLUSION

Based on GRADE assessment of the primary outcomes in trials with low risk of bias, the results are low or very low quality of evidence due to imprecision, inconsistency, and in some outcomes indirectness. Firm evidence for use of gabapentin is lacking as clinically relevant beneficial effect of gabapentin may be absent and harm is imminent, especially when added to multimodal analgesia.

The Effect of Preoperative Gabapentin on Postoperative Nausea and Vomiting: A Meta-Analysis

BACKGROUND

Preoperative gabapentin has been shown to improve postoperative pain and limit reliance on opioid analgesia. On the basis of an alternative mechanism, our group investigated the ability of preoperative gabapentin to prevent postoperative nausea and vomiting (PONV).

METHODS

We performed a meta-analysis of trials that reported outcomes on the effect of preoperative gabapentin on PONV end points in patients undergoing general anesthesia. In our primary analysis, we calculated the pooled antiemetic effects of preoperative gabapentin in studies with PONV as the primary end point. In our secondary analysis, we calculated the pooled effects in trials involving preoperative gabapentin that reported on the side effects, nausea and vomiting.

RESULTS

Among the trials designed with PONV as a primary end point (8 trials; n = 838), preoperative gabapentin was associated with a significant reduction in PONV (risk ratio [RR] = 0.60; 99% confidence interval [CI], 0.50-0.72; P < 0.0001), nausea (RR = 0.34; 99% CI, 0.20-0.56; P < 0.0001), and vomiting (RR = 0.34; 99% CI, 0.19-0.61; P = 0.0002) at 24 hours. Among all included trials (44 trials; n = 3489) that reported on the side effects, nausea and vomiting, similar reductions were noted in PONV with preoperative gabapentin administration. Subgroup analysis of trials excluding repeat dosing, thiopental induction, and nitrous oxide maintenance and including high-risk surgery resulted in similar PONV efficacy. Preoperative gabapentin is also associated with significantly increased rates of postoperative sedation (RR = 1.22; 95% CI, 1.02-1.47; P = 0.03) compared with control.

CONCLUSIONS

Preoperative gabapentin is associated with a significant reduction in PONV among studies designed to investigate this end point. Preoperative gabapentin should be considered not only as part of a multimodal approach to postoperative analgesia, but also for prevention of PONV.

Gabapentin for Perioperative Analgesia in Otorhinolaryngology-Head and Neck Surgery: Systematic Review

OBJECTIVE

Recent research has investigated the role of gabapentin in perioperative pain relief in otorhinolaryngology-head and neck surgery. This review aims to identify whether sufficient evidence exists for the routine use of gabapentin in the perioperative setting.

DATA SOURCES

MEDLINE, Cochrane CENTRAL, EMBASE, and Google Scholar.

REVIEW METHODS

A comprehensive systematic search was performed with keywords for articles up to November 2015. The systematic review included all randomized, placebo-, and active-controlled trials investigating the role of perioperative gabapentin for pain in otorhinolaryngology-head and neck surgery. The studies were assessed for risk of bias and selected and reviewed by the main author. Selected trials were required to have data in the form of pain intensity scores, analgesic consumption, adverse effects, or return to normal function.

RESULTS

A total of 14 randomized controlled trials were included, of which 4 had an active control. The placebo-controlled trials included 4 for tonsillectomy, 3 for rhinology, and 3 for thyroidectomy. These studies were not suitable for meta-analysis. Trial quality involving gabapentin in tonsillectomy surgery is variable. The higher-quality studies reported significantly reduced analgesic consumption in the gabapentin groups, with the effect on pain scores less clear. There was a significant benefit, within the first 24 hours, in pain and analgesic consumption as compared with placebo favoring the gabapentin groups following rhinologic and thyroid surgery.

CONCLUSION

Overall, gabapentin appears to have a significant beneficial effect on perioperative pain relief and analgesic consumption in otorhinolaryngology-head and neck surgery procedures within the first 24 hours.

Multi-Modal Preemptive Analgesia With Pregabalin, Acetaminophen, Naproxen, and Dextromethorphan in Radical Neck Dissection Surgery: A Randomized Clinical Trial

Background

Preemptive analgesia may be considered as a method not only to alleviate postoperative pain but also to decrease analgesic consumption. Different regimens are suggested, but there is currently no standard.

Objectives

The aim was to measure the efficacy of preemptive analgesia with pregabalin, acetaminophen, naproxen, and dextromethorphan in radical neck dissection surgery for reducing the intensity of pain and morphine consumption.

Patients and Methods

This study was conducted as a randomized double-blind clinical trial. Eighty adult patients (18 to 60 years of age) under the American society of anesthesiologists (ASA) physical status I and II undergoing elective radical neck dissection were enrolled. Patients were randomized into two groups of 40 with a simple randomization method. The case group received a combination of 15 mg/kg acetaminophen, 2.5 mg/kg pregabalin, 7 mg/kg naproxen, and 0.3 mg/kg dextromethorphan administered orally one hour prior to surgery. Postoperative pain was assessed with the universal pain assessment tool (UPAT) at 0, 2, 4, 6, 12, and 24 hours after surgery. Subjects received morphine based on postoperative pain control protocol. Total administered morphine doses were noted.

Results

Postoperative pain rates at 0, 2, 4, 6, 12, and 24 hours after surgery were significantly lower for the case group than the control group (P values = 0.014, 0.003, 0.00, 0.00, and 0.00, respectively). Total morphine doses for the preemptive analgesia group were 45% lower than those of the other group. Side effects were similar for both groups.

Conclusions

A single preoperative oral dose of pregabalin, acetaminophen, dextromethorphan, and naproxen one hour before surgery is an effective method for reducing postoperative pain and morphine consumption in patients undergoing radical neck dissection.

A case of gait disturbance caused by low-dose gabapentin

Gabapentin, an anticonvulsant agent, is now often used for the treatment of neuropathic pain all over the world. It is unclear whether the combined use of gabapentin, sodium valproate, and flunitrazepam results in enhancement of the side effect, a gait disturbance. A 60-year-old man was taking oral sodium valproate for symptomatic epilepsy after a brain contusion and flunitrazepam to relieve insomnia. Oral gabapentin therapy was started for suspected neuropathic pain. Although the initial dose of oral gabapentin (200 mg) relieved the pain, the lower extremities became weak, resulting in a gait disturbance. The therapy was restarted with a halved dose, and this resolved the gait disturbance and relieved the pain.

Three -Agent Preemptive Analgesia, Pregabalin-Acetaminophen-Naproxen, in Laparotomy for Cancer: A Randomized Clinical Trial

Background

Pain management after abdominal surgery is a critical issue in cancer patients undergoing laparotomy. Opioid analgesics commonly used postoperatively have significant side effects and can postpone restoring normal life. Administration of analgesics before the surgery by inhibiting pain cascades may be an effective method for more efficient pain control.

Objectives

This study aimed to investigate the effect of the preemptive use of oral pregabalin-acetaminophen-naproxen on pain control and morphine consumptions in cancer patients undergoing laparotomy.

Patients and Methods

A total of 40 cancer patients scheduled for open abdominal surgery were randomized into the two groups. one group received combination of pregabalin 150 mg, acetaminophen 1 g and naproxen 250 mg (the PAN group) an hour before laparotomy. Following the surgery, morphine was administered on a protocolized schedule based on patients’ demand for pain control. Postoperative pain level was assessed using universal pain assessment tool (UPAT) at 0, 2, 4, 6, 12, 24 and 48 hours after the operation. The postoperative morphine dose and complications were noted. Data were analyzed using SPSS version 16.

Results

Patients in the PAN group had significantly lower UPAT scores at 0, 2, 4, 6, 12, 24 and 48 hours after the surgery than those in the control group (P = 0.008, 0.021, 0.008, 0.047, 0.004, 0.001, and 0.001). The mean dose of postoperative morphine consumption in the PAN group was 37% less than the control group (P = 0.001). The complications were not significantly different between the two groups.

Conclusions

Preemptive use of pregabalin-acetaminophen-naproxen decreases intensity of pain and morphine consumption in the cancer patients after laparotomy without significant complications.

Post-tonsillectomy pain control: consensus or controversy?

Pediatric post-tonsillectomy analgesia continues to be highly debated and an area of active research. Tonsillectomy pain can lead to significant patient morbidity, and incur potentially avoidable healthcare costs. Moreover, the various analgesic classes, each present their own risk profiles and unique side effects when used in children post-tonsillectomy. This review delineates the clinical and pathophysiological basis for post-tonsillectomy pain, types of analgesics and their risk profiles, as well as special considerations in this clinical population and a review of alternative analgesic treatment options. This article presents a summary of recent literature and discusses evidence-based management options to aid medical and allied health professionals who may encounter these patients.

The efficacy of gabapentin/pregabalin in improving pain after tonsillectomy: A meta-analysis

OBJECTIVES/HYPOTHESIS

Gabapentin and pregabalin are useful for treating neuropathic pain because of their antiallodynic and antihyperalgesic properties, which may be beneficial in managing acute postoperative pain. The goal of this meta-analysis was to perform a systematic review of the literature on the effect of gabapentinoids on postoperative pain following tonsillectomy, and its adverse effects in patients.

DATA SOURCES

MEDLINE, SCOPUS, and Cochrane database.

METHODS

Two authors independently searched the databases from their inception of article collection to May 2015. Included in the analysis were studies that compared preoperative gabapentinoid administration (gabapentinoids groups) with a placebo or pain control agent (control group) during a 24-hour postoperative period, the outcomes of interest being postoperative pain intensity; rescue analgesic consumption; or adverse effects such as sedation, nausea and vomiting, dizziness, and headache.

RESULTS

The pain score reported by the physician during the first 8 hours, as well as the need for analgesics during 24 hours postoperatively, were significantly decreased in the gabapentinoids group versus the control group. Additionally, there was no significant difference between gabapentinoids and control groups for adverse effect during 24 hours postoperatively. In the subgroup analyses (gabapentin and pregabalin) regarding pain-related measurements, two subgroups showed the similar effect on reducing the postoperative pain severity.

CONCLUSION

Preoperative administration of gabapentinoids could provide pain relief without side effects in patients undergoing tonsillectomy. However, considering the insufficient evaluation of efficacy of gabapentinoids according to the high heterogeneity in some parameters, further clinical trials with robust research methodology should be conducted in order to confirm the results of this study.

LEVEL OF EVIDENCE

NA.

The effects of preoperative oral pregabalin and perioperative intravenous lidocaine infusion on postoperative morphine requirement in patients undergoing laparatomy

For the treatment of postoperative pain, multimodal analgesia can reduce the side effects and required dose of opioids by combining drugs and methods with different modes of action. This study evaluated the efficacy of preoperative oral pregabalin and perioperative intravenous lidocaine in patients undergoing laparotomy.

OBJECTIVES:

To evaluate and compare the effects of preoperative oral pregabalin and perioperative intravenous lidocaine infusion on postoperative morphine requirement, adverse effects, patients’ satisfaction, mobilization, time to first defecation and time to discharge in patients undergoing laparotomy.

METHODS:

Eighty patients (18 to 65 years of age) undergoing elective laparotomy were randomly divided into four groups (n=20 in each group): group C, placebo capsules and normal saline infusion perioperatively (control); group L, placebo capsules and lidocaine 1 mg/kg intravenous bolus dose followed by 2 mg/kg/h infusion until skin closure; group P, 150 mg oral pregabalin and normal saline infusion perioperatively; and group PL, 150 mg oral pregabalin and lidocaine 2 mg/kg/h infusion until skin closure. Hemodynamic parameters, visual analogue scale (VAS) scores, analgesic consumption, side effects, time to mobilization, time to first defecation, time to discharge and patients’ satisfaction were recorded.

RESULTS:

VAS scores of group L, group P and group PL were lower than group C (P<0.05). Morphine consumption of group P and group PL was lower than group C (P<0.05). Incidence of nausea in group C was higher than group L and group PL. Time to first defecation and mobilization were shorter in group L and group PL compared with group C (P<0.05).

CONCLUSION:

Preoperative oral pregabalin and perioperative intravenous lidocaine infusion decreased postoperative VAS scores. Preoperative oral pregabalin decreased morphine requirement and perioperative intravenous lidocaine infusion hastened gastrointestinal motility and mobilization, and decreased the incidence of nausea in patients undergoing laparotomy. Therefore, preoperative pregabalin with or without lidocaine provides superior pain relief in patients undergoing laparatomy.

Comparison between preemptive gabapentin and paracetamol for pain control after adenotonsillectomy in children

Background:

Tonsillectomy is the most commonly performed surgical procedure in ENT practice. Postoperative pain remains the major problem following tonsillectomy, if not treated. Different methods and many drugs have been used to control the postoperative pain. In this study, we evaluate the role of gabapentin premedication vs paracetamol in management of postoperative pain following adenotonsillectomy in children.

Materials and Methods:

In a double blind randomized study, 70 children were subjected for adenotonsillectomy classified into two equal groups. Group I: Gabapentin 10 mg/kg was given orally 2 hours before induction of anesthesia (Gabapentin syrup 250 mg/5 ml); Group II: Oral paracetamol 20 mg/kg was given orally 2 hours before induction of anesthesia. All children underwent general anesthesia. Pain score was assisted postoperatively 2 hours, 4 hours, 6 hours, 8 hours, 12 hours, and 18 hours after recovery using visual analogue scale (VAS).

Result:

Pain score in gabapentin group was significantly less in 2 hours, 4 hours, 6 hours, and 8 hours postoperatively than in paracetamol group (P=0.0003, <0.0001, 0.0004, <0.0001, respectively). The time to first analgesia was longer in the gabapentin group than paracetamol group (7.95±2.06 hours vs 5.85±1.87 hours; P<0.0001) and the total amount of pethedine was less in gabapentin group than in paracetamol group (8±10.05 mg vs 16.25±11.57 mg; P=0.002).

Conclusion:

Gabapentin premedication improves postoperative analgesia following adenotonsillectomy in children and reduce analgesic requirements in comparison with paracetamol premedication, with no reported side effects.

The effectiveness of pregabalin for post-tonsillectomy pain control: a randomized controlled trial

BACKGROUND

Although various analgesics have been used, postoperative pain remains one of the most troublesome aspects of tonsillectomy for patients.

OBJECTIVE

The aim of the present study was to evaluate the effectiveness of premedication using pregabalin compared with placebo (diazepam) on postoperative pain control in patients undergoing tonsillectomy.

METHODS

Forty-eight adult patients were randomly divided into a control group and a pregabalin group. Preoperatively, patients in the control group received 4 mg diazepam orally as placebo, whereas those in the pregabalin group received 300 mg pregabalin orally. All participants were provided with patient-controlled analgesia using fentanyl for 24 hours after surgery. Postoperative pain treatment included acetaminophen 650 mg three times daily for 8 postoperative days. The primary outcome measure was the total amount of patient-controlled fentanyl consumption after tonsillectomy. Secondary outcome measures were the number of injections of ketorolac tromethamine (each 30 mg) requested by patients, pain scores, overall satisfaction scores, drowsiness, nausea, dizziness, headache, and vomiting after the surgery. P < 0.05 was considered statistically significant.

RESULTS

The total amount of fentanyl demanded decreased significantly in the pregabalin group (P < 0.001). There were no significant differences in the number of ketorolac tromethamine injections, pain scores, overall satisfaction scores, drowsiness, nausea, dizziness, headache, and vomiting between the two groups.

CONCLUSION

Administration of 300 mg pregabalin prior to tonsillectomy decreases fentanyl consumption compared with that after 4 mg diazepam, without an increased incidence of adverse effects.

TRIAL REGISTRATION

KCT0001215.

The efficacy of honey for ameliorating pain after tonsillectomy: a meta-analysis

Postoperative pain and wound healing following tonsillectomy can result in dissatisfaction for the patient. However, there is no consensus on whether postoperatively administered honey effectively reduces morbidity after tonsillectomy. Therefore, a systematic review with a meta-analysis of the efficacy of honey as a treatment for postoperative pain and wound healing was performed. Two authors independently searched the database records (MEDLINE, SCOPUS, and Cochrane databases) dating from inception to June 2014. Studies comparing postoperative oral administration of honey with administration of placebo where the outcomes of interest were pain and wound healing on postoperative days were included. Baseline study characteristics, study quality, numbers of patients in steroid-treated and control groups, and treatment outcomes were extracted. Sufficient data for meta-analysis were retrieved from 4 trials with a total of 264 patients. We analyzed patient-reported pain scores and quantities of administered analgesics during the first 5 postoperative days. The pain score was significantly decreased in the honey-treated patients in comparison with the placebo-treated patients on postoperative day 1 only, but the analgesic intake of the honey-treated patients on the first 5 postoperative days was significantly less than that of the placebo-treated patients. In addition, honey significantly increased tonsillectomy bed wound healing in comparison with placebo during the first 2 weeks after surgery. This meta-analysis shows that postoperative administration of honey after tonsillectomy significantly reduces pain and promotes wound healing. Further trials comparing honey with good research methodology should be conducted to confirm these results.

Evaluation of gabapentin and dexamethasone alone or in combination for pain control after adenotonsillectomy in children

Background:

Different methods and many drugs have been used to control the post-operative pain. In this study, we evaluate the role of gabapentin premedication and/or dexamethasone in management of post-operative pain following adenotonsillectomy in children.

Materials and Methods:

In a double-blind randomized study, 120 children were subjected for adenotonsillectomy classified into three equal groups. Group G: Gabapentin 10 mg/kg was given orally 2 h before induction of anesthesia (Gabapentin syrup 250 mg/5 ml. Group D: Children in this group received placebo pre-operatively and received dexamethasone 0.15 mg/kg intravenously after induction of anesthesia, but before surgery. Group C: Children in this group received combination of oral gabapentin 10 mg/kg 2 h before induction of anesthesia and intra-operative 0.15 mg/kg dexamethasone intravenously. All children underwent general anesthesia. Pain score was assisted post-operatively 2 h, 4 h, 6 h, 8 h, 12 h and 18 h after recovery using face, legs, activity, cry, consolability scale.

Results:

Pain score in Group C and Group G was significantly less at 4 h, 6 h and 8 h post-operatively than in Group D (P < 0.05). At 12 h, the pain score in Group C was significantly less than Group G and Group D (P < 0.05). And no significant changes were observed in pain score at 18 h post-operatively between all groups (P > 0.05). The time to first analgesia was longer in the Group C than in Group G and Group D and the time to first analgesia was significantly longer in Group G than in Group D (P < 0.05). The total amount of pethidine was less in Group C and Group G than in Group D (P < 0.05). The incidence of post-operative nausea and vomiting was statically insignificant among all groups and no reported post-operative bleeding.

Conclusion:

Gabapentin 10 mg/kg premedication combined with intra-operative dexamethasone 0.15 mg/kg prolongs the post-operative analgesia following adenotonsillectomy in children and decreases the amount of pethidine used post-operatively with no reported adverse effects or increase in the incidence of post-operative bleeding.

Gabapentin's anti-nausea and anti-emetic effects: a review

Gabapentin's main clinical use is in the treatment of neuropathic pain where its binding to neuronal alpha-2/delta subunits of voltage-gated calcium channels (VGCCs) is critical to its mechanism of action. Over the past 10 years, there have been several reports of gabapentin also having anti-nausea and anti-emetic effects in conditions including postoperative nausea and vomiting (PONV), chemotherapy-induced nausea and vomiting (CINV), and hyperemesis gravidarum (HG). In this report, a MEDLINE electronic search was performed, and relevant citations were reviewed and classified by level of evidence; a grade of recommendation was then assigned for gabapentin's use for each studied indication. Out of 33 clinical trials reviewed, 12 assessed nausea and/or vomiting (N/V) associated with gabapentin therapy as primary outcome measures. These 12 studies provided a Grade A recommendation for gabapentin use in treating PONV, a Grade B recommendation for use in treating CINV, and a Grade C recommendation for use in treating HG. Further research is needed to confirm these initial promising results, which implicate the alpha-2/delta VGCC subunit as a novel therapeutic target in the treatment of several N/V-associated clinical conditions.

Comparison of analgesic effect between gabapentin and diclofenac on post-operative pain in patients undergoing tonsillectomy

Background

Tonsillectomy is a common procedure causing considerable postoperative pain. Postoperative pain intensity of 60 - 70 in the scale of visual analog scale (VAS) has been reported up to 3 - 4 days which could continue until 11 days after the surgery.

Objectives

The current study aimed to compare the analgesic effect of gabapentin and diclofenac on pain after tonsillectomy with the control group.

Patients and Methods

In this double-blind, placebo-controlled clinical trial, 90 patients aged 10-25 years, ASA classes I and II were randomly selected to receive 20 mg/kg oral gabapentin (n = 30), 1.0 mg / kg rectal diclofenac (n = 30) or placebo (n = 30) preoperatively. Pain was evaluated postoperatively on a visual analogue scale at 2, 6, 12 and 24 h. Opioid consumption in the first 24 h after surgery and the side effects were also recorded.

Results

There was no significant difference in terms of age, sex, and time of surgery in the three groups. Patients in the gabapentin and diclofenac groups had significantly lower pain scores at all-time intervals than those in the placebo group. The total meperidine consumed in the gabapentin (14.16 ± 6.97 P = 0.001) and diclofenac (16.66 ± 8.95, P = 0.004) groups was significantly less than that of the placebo (33.4 ± 13.97) group. The frequency of side effects such as vomiting, dizziness, and headache was not significantly different among the groups.

Conclusions

It can be concluded that gabapentin and diclofenac reduced postoperative pain and opioid consumption without obvious side effects.

Strategies Aimed at Preventing Chronic Post-surgical Pain: Comprehensive Perioperative Pain Management after Total Joint Replacement Surgery

PURPOSE

Chronic post-surgical pain (CPSP) is a frequent outcome of musculoskeletal surgery. Physiotherapists often treat patients with pain before and after musculoskeletal surgery. The purposes of this paper are (1) to raise awareness of the nature, mechanisms, and significance of CPSP; and (2) to highlight the necessity for an inter-professional team to understand and address its complexity. Using total joint replacement surgeries as a model, we provide a review of pain mechanisms and pain management strategies.

SUMMARY OF KEY POINTS

By understanding the mechanisms by which pain alters the body's normal physiological responses to surgery, clinicians selectively target pain in post-surgical patients through the use of multi-modal management strategies. Clinicians should not assume that patients receiving multiple medications have a problem with pain. Rather, the modern-day approach is to manage pain using preventive strategies, with the aims of reducing the intensity of acute postoperative pain and minimizing the development of CPSP.

CONCLUSIONS

The roles of biological, surgical, psychosocial, and patient-related risk factors in the transition to pain chronicity require further investigation if we are to better understand their relationships with pain. Measuring pain intensity and analgesic use is not sufficient. Proper evaluation and management of risk factors for CPSP require inter-professional teams to characterize a patient's experience of postoperative pain and to examine pain arising during functional activities.

Pregabalin and dexamethasone improves post-operative pain treatment after tonsillectomy

BACKGROUND

Post-tonsillectomy pain can be severe. We investigated the analgesic effect from combinations of paracetamol, pregabalin and dexamethasone in adults undergoing tonsillectomy.

METHODS

In this randomized double-blind study, 131 patients were assigned to either group A (paracetamol+placebo), group B (paracetamol+pregabalin+placebo) or group C (paracetamol+pregabalin+dexamethasone). Pre-operatively, patients received either paracetamol 1000 mg, pregabalin 300 mg, dexamethasone 8 mg or placebo according to their allocation. Post-operative pain treatment included paracetamol 1000 mg 4× and ketobemidone 2.5 mg p.n. Ketobemidone consumption, pain scores [visual analogue scale (VAS)], nausea, sedation, dizziness, number of vomits and consumption of ondansetron were recorded 2, 4 and 24 h after the operation. P<0.05 was considered statistically significant.

RESULTS

The mean 24-h VAS-pain score at rest was reduced in group C (P<0.003) vs. group A. The mean 24-h VAS-pain scores during swallowing were reduced in group B (P=0.009) and group C (P<0.003) vs. group A. Consumption of ketobemidone (1-4 h post-operatively) was lower in group B (P=0.003) and group C (P=0.003) vs. group A. The mean 24-h dizziness score was higher in group B (P<0.003) and C (P=0.003) vs. group A. Other parameters including re-operation for post-tonsillectomy bleeding were not different between groups.

CONCLUSION

Pregabalin and pregabalin+dexamethasone reduced post-operative pain scores and consumption of ketobemidone following tonsillectomy. Dizziness was increased with pregabalin.

An enhanced bunionectomy model as a potential tool for early decision-making in the development of new analgesics

BACKGROUND

bunionectomy has been used as a model of postoperative pain for opioids and nonsteroidal anti-inflammatory drugs/cyclooxygenase-2 inhibitors with a fast onset of analgesia. The present study was conducted to assess whether the utility of the model can be broadened in assessing the efficacy of analgesics with diverse mechanisms and pharmacokinetic profiles in drug development and to enhance the sensitivity of a bunionectomy model.

METHODS

this was a single center, randomized, double-blind, placebo-controlled, three-arm, parallel group methodology study to evaluate the effects of pregabalin and naproxen sodium on postoperative pain following bunionectomy. Patients (n=100) were randomized 1:1:1 to three treatments (administered 1 hour before and at defined intervals after surgery): pregabalin 300 mg before surgery and 150 mg every 8 hours; naproxen sodium 550 mg before surgery and 550 mg every 12 hours; or placebo in a double-dummy fashion. Primary endpoints were patient-controlled analgesic (PCA) hydromorphone consumption and the time to first PCA hydromorphone use postsurgery over 24 hours.

RESULTS

of the 100 patients randomized, 96 completed the study. Relative to placebo, pregabalin and naproxen sodium, respectively, reduced PCA hydromorphone consumption by 51% (P=0.005) and 65% (P<0.001) and increased the median time to first use of PCA hydromorphone by 1.5 hours (P=0.004) and 3.7 hours (P<0.001). Both drugs significantly (P<0.050) decreased use of oral opioid rescue medication over 24-48 hours postsurgery relative to placebo. Although there were no statistically significant differences between naproxen sodium and pregabalin in opioid consumption and global evaluation of medication, overall naproxen sodium appeared to be more effective at reducing pain.

CONCLUSIONS

the model provided a sensitive method for evaluating efficacy of compounds with diverse mechanisms and pharmacokinetic profiles. The robustness of the enhanced pain model renders bunionectomy pain a valuable tool to assess novel analgesic compounds in small numbers of subjects early in drug development.

Effect of Gabapentin on Pain after Cardiac Surgery: A Randomised, Double-Blind, Placebo-Controlled Trial

This study evaluated whether perioperative administration of gabapentin in cardiac surgery patients could reduce postoperative opioid consumption, postoperative sleep or perceived quality of recovery. This randomised controlled trial assigned 60 patients undergoing cardiac surgery to receive 1200 mg of gabapentin or placebo two hours preoperatively, and then 600 mg of gabapentin or placebo twice a day for the next two postoperative days. Postoperative opioid use was measured by the amount of fentanyl used in the first 48 hours postoperatively. Pain at rest and with movement at 12, 24, 48 and 72 hours after surgery, sleep scores on postoperative days two and three and patient-perceived quality of recovery were also assessed. Fentanyl use, visual analog pain scores, sleep scores, adjunctive pain medication use and number of anti-emetics given were not significantly different between the gabapentin and placebo groups. The incidence of side-effects was similar between the gabapentin and placebo groups, and no difference was found between groups in relation to quality of recovery. These findings indicate that preoperative use of gabapentin followed by postoperative dosing for two days did not significantly affect the postoperative pain, sleep, opioid consumption or patient-perceived quality of recovery for patients undergoing cardiac surgery.

Gabapentin decreases morphine consumption and improves functional recovery following total knee arthroplasty

BACKGROUND

Moderate to severe pain after total knee arthroplasty often interferes with postoperative rehabilitation and delays discharge from hospital. The present study examined the effects of a four-day postoperative gabapentin (GBP) regimen versus placebo on opioid consumption, pain scores and knee flexion, as well as adverse effects, after total knee arthroplasty.

METHODS

After obtaining research ethics board approval and informed consent, 40 patients were enrolled in a randomized, single-blind, placebo-controlled, open-label study. Patients were assigned to one of five groups - preoperative placebo/postoperative placebo (G1), preoperative GBP 600 mg/postoperative placebo (G2), preoperative GBP 600 mg/postoperative GBP 100 mg three times per day (G3), preoperative GBP 600 mg/ postoperative GBP 200 mg three times per day (G4) and preoperative GBP 600 mg/postoperative GBP 300 mg three times per day (G5). Postoperative GBP or placebo was continued for four days after surgery. Two hours before surgery, all patients received celecoxib 400 mg. Based on the above groupings, patients in G1 received placebo medication, whereas patients in G2, G3, G4 and G5 received gabapentin 600 mg 2 h preoperatively. All patients received femoral and sciatic nerve blocks, followed by spinal anesthesia. Beginning in the postanesthetic care unit, all patients received a regimen of celecoxib 200 mg every 12 h for four days and a patient-controlled morphine analgesia pump for 48 h.

RESULTS

Thirty-six patients (G1, n=7; G2, n=7; G3, n=8; G4, n=7; G5, n=7) completed the study. Data were analyzed by one-way ANOVA followed by a contrast comparing patients who received postoperative GBP (G3, G4 and G5) (n=22) with patients who received placebo postoperatively (G1 and G2) (n=14). Patients who received GBP postoperatively used significantly less patient-controlled morphine analgesia at 24 h, 36 h and 48 h (P<0.05). The postoperative GBP patients had significantly better active assisted knee flexion on postoperative days 2 and 3, with a trend toward better flexion on postoperative day 4. Patients who received GBP postoperatively reported less pruritus than patients who received placebo. There were no differences in pain scores.

CONCLUSIONS

These results support the use of GBP in the acute postoperative period. Further trials are needed to delineate the optimal dose, timing and duration of GBP use following surgery.

Adding gabapentin to a multimodal regimen does not reduce acute pain, opioid consumption or chronic pain after total hip arthroplasty

BACKGROUND

Gabapentin (GPN) is effective in reducing post-operative pain and opioid consumption, but its effects with regional anesthesia for total hip arthroplasty (THA) are not known. We designed this study to determine whether (1) gabapentin administration reduces pain and opioid use after THA using a multimodal analgesic regimen including spinal anesthesia; (2) pre-operative administration of gabapentin is more effective than post-operative administration.

METHODS

After REB approval and informed consent, 126 patients were enrolled in a double-blinded, randomized-controlled study. Patients received acetaminophen 1 g per os (p.o.), celecoxib 400 mg p.o. and dexamethasone 8 mg intravenously, 1-2 h pre-operatively. Patients were randomly assigned to one of three treatment groups (G1: Placebo/Placebo; G2: GPN/Placebo; G3: Placebo/GPN). Patients received gabapentin 600 mg (G2) or placebo (G1 and G3) 2 h before surgery. All patients had spinal anesthesia [15 mg (3cc) of 0.5% hypobaric bupivacaine with 10 microg of fentanyl]. In the post-anesthetic care unit, patients received gabapentin 600 mg (G3) or placebo (G1 and G2). On the ward, patients received acetaminophen 1000 mg p.o. q6h, celecoxib 200 mg p.o. q12h and a morphine PCA device. Patients were interviewed 6 months post-surgery to determine the incidence and severity of chronic post-surgical pain.

RESULTS

Mean+/-SD cumulative morphine (mg) consumption (G1=49.4+/-24.8, G2=47.2+/-30.1 and G3=56.1+/-38.2) at 48 h and pain scores at 12, 24, 36 and 48 h post-surgery were not significantly different among the groups [G1 (n=38), G2 (n=38) and G3 (n=38)]. Side effect profiles were similar across groups. Six months after surgery, the number of patients who reported chronic post-surgical pain (G1=10, G2=12 and G3=9) and the severity of the pain (G1=4.2+/-2.9, G2=4.1+/-2.2 and G3=4.9+/-2.2) did not differ significantly among the groups (P>0.05).

CONCLUSIONS

A single 600 mg dose of gabapentin given pre-operatively or post-operatively does not reduce morphine consumption or pain scores in hospital or at 6 months after hip arthroplasty within the context of spinal anesthesia and a robust multimodal analgesia regimen.

Multimodal analgesia for hip arthroplasty

Multimodal analgesia incorporates the use of analgesic adjuncts with different mechanisms of action to enhance postoperative pain management. Acetaminophen, anti-inflammatories, and gabapentinoids provide effective analgesia while reducing opioid requirements and opioid-related side effects. Intrathecal morphine and periarticular local anesthetic infiltration further enhance dynamic analgesia and improve postoperative mobilization. Epidural analgesia, peripheral nerve blocks, tramadol, ketamine, and/or clonidine can be added for improved benefit in opioid-tolerant individuals.

The effectiveness of gabapentin on post-tonsillectomy pain control

Postoperative pain is one of the most troublesome aspects of tonsillectomy for patients. Although various analgesics have been administered for pain control following tonsillectomy, it has still not been effectively controlled. Therefore, this study was conducted to evaluate the effectiveness of premedication using gabapentin on postoperative pain control in patients undergoing tonsillectomy. A total of 58 adult patients were randomly divided into a control group and a gabapentin group. Patients in the control group received an oral placebo preoperatively, whereas those in the gabapentin group received an oral dose of gabapentin preoperatively. All participants were provided with patient-controlled analgesia using fentanyl for 48 h after surgery. The total amount of fentanyl injected and the number of injections of dicolfenac sodium (75 mg each) requested by each of the group was then compared. Pain assessment was performed using a visual analog scale during resting periods (rVAS) and during swallowing (sVAS) for 9 days after the operation. The number of dicolfenac sodium injections and the total amount of fentanyl injected decreased significantly in the gabapentin group (P < 0.01). The sVAS of the gabapentin group was also significantly lower than that of the control group at 2 and 4 h after surgery, but there were no significant differences in the sVAS observed between the two groups for the remainder of the postoperative period. There were no significant differences in the rVAS observed between the two groups throughout the postoperative period. Thus, premedication with gabapentin decreased post-tonsillectomy pain. So the addition of gabapentin prior to tonsillectomy may have an adjunctive role in pain control.

Gabapentin and pregabalin for chronic neuropathic and early postsurgical pain: current evidence and future directions

PURPOSE OF REVIEW

Gabapentin and pregabalin bind to the alpha-2-delta calcium channel subunit and represent a novel analgesic drug class. The evidence base supporting their use for chronic neuropathic and early postsurgical pain is reviewed.

RECENT FINDINGS

Multiple, large, high-quality trials have demonstrated the safety and efficacy of gabapentin and pregabalin in neuropathic pain. Treatment-related improvement of pain and sleep positively impact upon quality of life. Sedation, dizziness and ataxia are important and relatively common adverse effects, however. Accumulating evidence indicates that gabapentin, and possibly pregabalin, also exert important effects following surgery. Multiple high-quality trials have demonstrated analgesic and opioid-sparing efficacy with gabapentin following various surgical procedures. Gabapentin and pregabalin reduce movement-evoked pain and this can lead to enhanced functional postoperative recovery. Postoperative opioid sparing is of questionable relevance since few trials have shown reduced opioid-related adverse effects. Sedation, dizziness and ataxia have been reported in only a few trials. Future larger-scale perioperative trials focused on safety assessment are needed, however.

SUMMARY

Gabapentin and pregabalin are efficacious treatments for neuropathic and postsurgical pain. Future research addressing several specific questions would serve to better delineate their optimal roles in treating these and other pain conditions.

Gabapentin and postoperative pain: a qualitative and quantitative systematic review, with focus on procedure

Background

Gabapentin is an antiepileptic drug used in a variety of chronic pain conditions. Increasing numbers of randomized trials indicate that gabapentin is effective as a postoperative analgesic. This procedure-specific systematic review aims to analyse the 24-hour postoperative effect of gabapentin on acute pain in adults.

Methods

Medline, The Cochrane Library and Google Scholar were searched for double-blind randomized placebo controlled trials of gabapentin for postoperative pain relief compared with placebo, in adults undergoing a surgical procedure.

Qualitative analysis of postoperative effectiveness was evaluated by assessment of significant difference (P < 0.05) in pain relief using consumption of supplemental analgesic and pain scores between study groups.

Quantitative analyses of combined data from similar procedures, were performed by calculating the weighted mean difference (WMD) of 24-hour cumulated opioid requirements, and the WMD for visual analogue scale (VAS) pain, (early (6 h) and late (24 h) postoperatively), between study groups. Side-effects (nausea, vomiting, dizziness and sedation) were extracted for calculation of their relative risk (RR).

Results

Twenty-three trials with 1529 patients were included. In 12 of 16 studies with data on postoperative opioid requirement, the reported 24-hour opioid consumption was significantly reduced with gabapentin. Quantitative analysis of five trials in abdominal hysterectomy showed a significant reduction in morphine consumption (WMD – 13 mg, 95% confidence interval (CI) -19 to -8 mg), and in early pain scores at rest (WMD – 11 mm on the VAS, 95% CI -12 to -2 mm) and during activity (WMD -8 mm on the VAS; 95% CI -13 to -3 mm), favouring gabapentin. In spinal surgery, (4 trials), analyses demonstrated a significant reduction in morphine consumption (WMD of – 31 mg (95%CI – 53 to -10 mg) and pain scores, early (WMD – 17 mm on the VAS; 95 % CI -31 to -3 mm) and late (WMD -12 mm on the VAS; 95% CI -23 to -1 mm) also favouring gabapentin treatment. Nausea was improved with gabapentin in abdominal hysterectomy (RR 0.7; 95 % CI 0.5 to 0.9). Other side-effects were unaffected.

Conclusion

Perioperative use of gabapentin has a significant 24-hour opioid sparing effect and improves pain score for both abdominal hysterectomy and spinal surgery. Nausea may be reduced in abdominal hysterectomy.

Do Surgical Patients Benefit from Perioperative Gabapentin/Pregabalin? A Systematic Review of Efficacy and Safety

BACKGROUND

Gabapentin and pregabalin have antiallodynic and antihyperalgesic properties useful for treating neuropathic pain. These properties may also be beneficial in acute postoperative pain. In this study we evaluated randomized, controlled trials examining the analgesic efficacy, adverse effects, and clinical value of gabapentinoids in postoperative pain.

METHODS

A systematic search of Medline, PubMed, and Cochrane Central Register of Controlled Trials (CENTRAL) databases yielded 22 randomized, controlled trials on perioperative administration of gabapentinoids for postoperative pain relief.

RESULTS

Pain relief was better in the gabapentin groups compared with the control groups. The opioid-sparing effect during the first 24 h after a single dose of gabapentin 300-1200 mg, administered 1-2 h preoperatively, ranged from 20% to 62%. The combined effect of a single dose of gabapentin was a reduction of opioid consumption equivalent to 30 +/- 4 mg of morphine (mean +/- 95% CI) during the first 24 h after surgery. Metaregression analysis suggested that the gabapentin-induced reduction in the 24-h opioid consumption was not significantly dependent on the gabapentin dose. Gabapentin reduced opioid-related adverse effects, such as nausea, vomiting, and urinary retention (number-needed-to-treat 25, 6, and 7, respectively). The most common adverse effects of the gabapentinoids were sedation and dizziness (number-needed-to-harm 35 and 12, respectively).

CONCLUSIONS

Gabapentinoids effectively reduce postoperative pain, opioid consumption, and opioid-related adverse effects after surgery. Conclusions about the optimal dose and duration of the treatment cannot be made because of the heterogeneity of the trials. Studies are needed to determine the long-term benefits, if any, of perioperative gabapentinoids.