Pregabalin: a new neuromodulator with broad therapeutic indications

The Effect of Oral Gabapentin and Pregabalin as a Prodrug in Pain Control after Orthopedic Surgery on the Upper Limb: A Double-Blind Parallel Randomized Clinical Trial Study

Objective

To compare the effects of oral gabapentin (GBP) and pregabalin (PGB) in pain control after orthopedic surgery on the upper limb.

Methods

In this double-blind randomized clinical trial study, 80 patients who were the candidates for elective orthopedic surgery on one of the parts of the upper limb were divided into two groups using balance-block randomization. For the first group, a 150 mg capsule of PGB (one hour before the surgery) and for the second group, a 300 mg capsule of GBP (two hours before the surgery) were prescribed. Patients were subjected to standard monitoring at the beginning and during surgery. The pain scores were evaluated at before surgery, in PACU (postanesthesia care unit), and 6 and 12 hours after the surgery by VAS (visual analog scale).

Results

In this study, 37 subjects were allocated to each group. The participation rate was 92.5%. The mean with 95% confidence interval (CI) of pain scores over 4 times in the PGB group was 4.03 (3.25-4.79), 3.76 (3.02-4.49), 3.65 (3.06-4.23), and 3.41 (2.88-3.93) and in the GBP group was 4.08 (3.33-4.83), 2.78 (2.11-4.45), 2.3 (2.05-2.54), and 2 (1.51-2.50), respectively. The within-group comparisons showed a significant decrease in the pain score over time (P < 0.001). Also, the between-group comparison showed significant differences between the two groups in terms of pain score (P < 0.001). In the end, results showed that there is a significant interaction between time and intervention for pain score (P=0.042).

Conclusion

Although two medicines led to a reduction in the pain score, but the rate reduction in the PGB group was significantly more than that in the GBP group. This trial is registered with IRCT20211013052759N1.

Analgesic Efficacy of Pre-operative Pregabalin in Dacryocystorhinostomy Surgery: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials

Dacryocystorhinostomy (DCR) is an effective surgical procedure for addressing lacrimal drainage problems. However, it can be a painful operation that involves incisions both inside and outside the eye, often leading to a high incidence of postoperative nausea and vomiting. Preemptive analgesics can be employed to alleviate this unrelieved pain. Nonetheless, many of the drugs used can induce a wide range of adverse effects. Therefore, the aim of this systematic review and meta-analysis is to assess the current evidence regarding the efficacy of pregabalin in managing postoperative pain following DCR surgery. We conducted a thorough search of five electronic databases, namely, PubMed, Web of Science, Scopus, Cochrane, and Google Scholar, to identify relevant randomized controlled trials (RCTs) published before September 2023. The quality of the included studies was assessed using the Cochrane Risk of Bias tool for RCTs. The outcomes we evaluated included postoperative pain, surgery duration, time to first analgesia, total pethidine consumption, and postoperative nausea and vomiting (PONV). Continues data reported as mean difference (MD), and dichotomous data reported as risk ratio (RR), with 95% confidence interval (CI). A pooled meta-analysis of three RCTs, including 240 patients in both the pregabalin and placebo groups, was conducted. The results revealed that the pooled MD in pain scores was significantly lower in patients treated with pregabalin compared to those receiving a placebo ((MD = -1.35 (95% CI: -1.83 to -0.87, p < 0.00001)). Additionally, the pooled MD of pethidine consumption was significantly lower in patients treated with pregabalin compared to those receiving a placebo (MD = -54.13 (95% CI: -103.77 to -4.50, p = 0.03)). However, there was no statistical significance between both groups in terms of time to first analgesia and duration of surgery (p > 0.05). On the other hand, the pooled RR of PONV was significantly lower in patients treated with pregabalin compared to those receiving a placebo (RR = 0.37 (95% CI: 0.24-0.57, p < 0.001)). This meta-analysis demonstrates that pregabalin is an effective and well-tolerated intervention for reducing postoperative pain and PONV following DCR surgery, without significantly affecting surgery duration or time to first analgesia. These findings support the use of pregabalin in improving patient comfort and outcomes in this surgical context.

Pregabalin alters reproductive performance in male mice and causes congenital anomalies in offspring

CONTEXT

Pregabalin is an anticonvulsant drug with analgesic activity for the treatment of neuropathic pain.

AIMS

To valuate the toxicity of pregabalin in reproductive parameters, spermatogenesis, and teratogenicity in the offspring of mice.

METHODS

Twenty male mice were randomly distributed into two groups: PGB group and group C (n =10 per group). The animals in the PGB group received, via gavage, 200mg/kg of pregabalin diluted in distilled water daily, for a period of 45days. Group C received distilled water under the same experimental design.

KEY RESULTS

In the paternal parameters of the PGB group, there was a significant increase in the size of the testicles, morphological alterations in the spermatozoa, a decrease in the Johnsen score, an increase in the Leydig cells, and a decrease in the serum level of testosterone. In the intrauterine development parameters of females mated with males from the PGB group, a significant decrease in placental weight, weight and length of fetuses, and fetal viability rate was observed. There was a significant increase in the number of resorptions and post-implantation losses. The significant anomalies observed in the offspring were alteration in the size of the kidneys, absent metacarpals and phalanges, alteration in the sternum, and supernumerary thoracic vertebrae.

CONCLUSION

Results suggest that pregabalin had toxic effects on the reproductive function of male mice and teratogenic potential.

IMPLICATIONS

The findings of this study may provide new hypotheses, taking into account the risk-benefit ratio for male reproduction and offspring health.

Pregabalin does not reduce postoperative pain after outpatient ACL surgery: A case-control study

INTRODUCTION

In France, prescribing pregabalin requires a secure prescription valid for 6 months since the decree of 12 February 2021, based on recommendations of the French Centre for Evaluation and Information on Pharmacodependence and Addiction vigilance (CEIP-A). This led to discontinuation of this treatment as a postoperative analgesic in the French ACL Study (FAST) cohort. We aimed to evaluate the impact of this change on early postoperative pain.

HYPOTHESIS

Pregabalin is an important analgesic for reducing early postoperative pain after anterior cruciate ligament (ACL) repair.

METHODS

At our healthcare facility, 584 patients from the FAST cohort who underwent primary isolated ACL reconstruction were included: 292 patients operated before June 1, 2021 who received pregabalin postoperatively and 292 patients operated after June 1, 2021 who did not receive pregabalin. The patients were matched based on age, sex, preoperative Lysholm and Tegner scores. Pain was evaluated on a visual analog scale (VAS) on D0 in the evening, D0 at night, D1, D2 and D3.

RESULTS

The patients who did not receive pregabalin had more severe pain at night on D0: 5.21 vs 5.68 (p=.048). There was no difference between groups in the postoperative pain at rest during the evening of D0 (p=.89), D1 (p=.33), D2 (p=.37) and D3 (p=.21).

CONCLUSION

In the context of outpatient arthroscopic ACL reconstruction, pregabalin does not reduce early postoperative pain in a clinically significant manner.

LEVEL OF EVIDENCE

IV; case-control study.

The Efficacy of Gabapentin + Dexamethasone for Postoperative Analgesia Following Septoplasty: A Prospective Randomized Placebo-Controlled Trial

AIMS

This study aimed to compare the efficacy of gabapentin, dexamethasone, and gabapentin + dexamethasone for pain control after septoplasty.

MATERIALS AND METHODS

This prospective randomized trial included 120 patients that underwent septoplasty and were randomly divided into 4 groups: group G (preoperative gabapentin 600 mg p.o.); group D (intraoperative dexamethasone 8 mg i.v.); group GD (preoperative gabapentin 600 mg p.o. + intraoperative dexamethasone 8 mg i.v.); group C (placebo control).

RESULTS

The median VAS score was significantly lower in groups G and GD at 1, 2, 4, 6, 12, and 24 hours postsurgery than in group C (P < .008 for all). The median VAS score was significantly lower in group D than in group C at 1, 2, and 4 hours postsurgery (P < .008 for all). There weren't any significant differences in the VAS score between groups D, G, and GD at any time point. Groups G, D, and GD had a significantly lower frequency of rescue analgesic use than group C; however, there were no differences between groups G, GD, and C (P < .001 and P = .108, respectively).

CONCLUSION

Gabapentin, dexamethasone, and gabapentin + dexamethasone are equally more effective analgesics during the first 4 hours postsurgery than placebo. The addition of dexamethasone to gabapentin does not provide extra analgesia. Both gabapentin and gabapentin + dexamethasone have a more prolonged analgesic effect than dexamethasone alone.

Comparison of a Non-Opioid Multimodal Analgesia Protocol with Opioid-Based Patient-Controlled Analgesia for Pain Control Following Robot-Assisted Radical Prostatectomy: A Randomized, Non-Inferiority Trial

Background

Opioid use after surgery is a potential contributor to the opioid epidemic. An adequate pain control method after surgery while minimizing opioid exposure is needed. This study aimed to compare the effect of non-opioid multimodal analgesia (NOMA) protocol with opioid-based patient-controlled analgesia (PCA) for pain relief after robot-assisted radical prostatectomy (RARP).

Methods

This prospective randomized, open, non-inferiority trial included 80 patients scheduled for RARP. The NOMA group received pregabalin, paracetamol, bilateral quadratus lumborum block, and pudendal nerve block. PCA group received PCA. Pain scores, postoperative nausea and vomiting, opioid requirements, and quality of recovery were recorded 48 hours after surgery.

Results

We found no significant differences in pain scores. The mean difference in pain score during rest at 24 h was 0.5 (95% CI -0.5 to 2.0). This result demonstrated the non-inferiority of NOMA protocol to PCA at our non-inferiority margin (-1). In addition, 23 patients in the NOMA group did not receive any opioid agonist for 48 h after surgery. Recovery of bowel function was also faster in the NOMA group than in the PCA group (25.0 hours vs 33.4 hours, p = 0.01).

Limitations

We did not evaluate whether our NOMA protocol could decrease the incidence of new continuous opioid use after surgery.

Conclusion

NOMA protocol successfully controlled postoperative pain and was non-inferior to morphine-based PCA regarding patient-reported pain intensity. It also promoted recovery of bowel function and decreased postoperative nausea and vomiting.

The α2δ-1-NMDA receptor complex and its potential as a therapeutic target for ischemic stroke

N-methyl-_D-aspartate receptors (NMDARs) play a critical role in excitotoxicity caused by ischemic stroke, but NMDAR antagonists have failed to be translated into clinical practice for treating stroke patients. Recent studies suggest that targeting the specific protein-protein interactions that regulate NMDARs may be an effective strategy to reduce excitotoxicity associated with brain ischemia. α2δ-1 (encoded by the Cacna2d1 gene), previously known as a subunit of voltage-gated calcium channels, is a binding protein of gabapentinoids used clinically for treating chronic neuropathic pain and epilepsy. Recent studies indicate that α2δ-1 is an interacting protein of NMDARs and can promote synaptic trafficking and hyperactivity of NMDARs in neuropathic pain conditions. In this review, we highlight the newly identified roles of α2δ-1-mediated NMDAR activity in the gabapentinoid effects and NMDAR excitotoxicity during brain ischemia as well as targeting α2δ-1-bound NMDARs as a potential treatment for ischemic stroke.

Targeting neuroinflammation as a preventive and therapeutic approach for perioperative neurocognitive disorders

Perioperative neurocognitive disorders (PND) is a common postoperative complication associated with regional or general anesthesia and surgery. Growing evidence in both patient and animal models of PND suggested that neuroinflammation plays a critical role in the development and progression of this problem, therefore, mounting efforts have been made to develop novel therapeutic approaches for PND by targeting specific factors or steps alongside the neuroinflammation. Multiple studies have shown that perioperative anti-neuroinflammatory strategies via administering pharmacologic agents or performing nonpharmacologic approaches exert benefits in the prevention and management of PND, although more clinical evidence is urgently needed to testify or confirm these results. Furthermore, long-term effects and outcomes with respect to cognitive functions and side effects are needed to be observed. In this review, we discuss recent preclinical and clinical studies published within a decade as potential preventive and therapeutic approaches targeting neuroinflammation for PND.

Pregabalin for chemotherapy-induced neuropathy: background and rationale for further study

Chemotherapy-induced neuropathy is difficult to manage, and the pain associated with neuropathy is poorly responsive to gabapentin in a randomized trial. Duloxetine is the only drug that has been found to be effective in reducing pain from chemotherapy neuropathy. In this qualitative review, the use of pregabalin for chemotherapy-induced neuropathy is discussed including the rationale and pharmacological reasons why pregabalin should be considered in a large, randomized placebo-controlled trial.

The preemptive effects of oral pregabalin on perioperative pain management in lower limb orthopedic surgery: a systematic review and meta-analysis

BACKGROUND

To systematically review the literature and provide a comprehensive understanding of the preemptive effects of oral pregabalin on perioperative pain management in lower limb orthopedic surgery.

METHOD

We searched three electronic databases for randomized controlled trials comparing the results of preoperative pregabalin and placebo in patients undergoing lower limb orthopedic surgery. Data analyses were conducted using RevMan 5.4.

RESULTS

Twenty-one randomized controlled trials met our inclusion criteria. The cumulative opioid consumption within 24 and 48 h postoperatively in the pregabalin group was significantly less than that in the placebo group. The pooled static pain intensity at all time points within the first day was significantly lower in the pregabalin group than in the placebo group. Lower dynamic pain intensity at 48 h was detected in the pregabalin group than in the placebo group. Meanwhile, pregabalin led to a lower incidence of nausea but appeared to be associated with a higher incidence of dizziness and sedation. Subgroup analyses showed that no difference was detected between subgroups stratified by dosing regimen or pregabalin dose in the results of opioid consumption, pain intensity and incidence of complications.

CONCLUSION

This meta-analysis supports the use of pregabalin preoperatively in patients undergoing lower limb orthopedic surgery. However, it was wary of the resulting increase in dizziness and sedation. There is no evidence to support the continued use of pregabalin postoperatively or using more than 150 mg of pregabalin per day.

TRIAL REGISTRATION

This study was registered on 09 November 2021 with INPLASY (registration number: INPLASY2021110031).

Evaluation of the postoperative morphine-sparing effect of oral premedicants used as pre-emptive analgesics in breast-conserving cancer surgeries: A randomised placebo-controlled trial

Background and Aims:

Breast cancer surgeries are associated with both nociceptive and neuropathic pain, requiring strong analgesics. We aimed to evaluate the postoperative morphine-sparing effect of pre-emptive oral premedication with tramadol versus pregabalin in patients undergoing breast-conserving cancer surgeries (BCCS).

Methods:

This prospective, randomised, placebo-controlled trial was carried out at tertiary care centre on 90 patients undergoing BCCS randomised into three groups of 30 each. Group C received placebo, Group T received tramadol 100 mg and Group P received pregabalin 75 mg as oral premedication, 1 hour before surgery. General anaesthesia was administered. Postoperatively morphine 1 mg.h^-1 through intravenous PCA was started at a visual analogue scale score ≥4. Total morphine consumption in 24 hours was calculated and its sparing effect was evaluated as the primary outcome.

Results:

The median with interquartile range (IQR) of total postoperative morphine consumed in 24 hours, was found to be 22 mg (IQR 0-25.77), 15 mg (IQR 0-16) and 17.50 mg (IQR 0-19.25) in groups C, T, P respectively, (P = 0.000, 0.003, 0.060). The median duration of analgesia in group C was 5.40 hours (IQR 3.30-11.40), 11.6 hours (IQR 9.30-24.0) in group T and 8.60 hours (IQR 6.97-16.27) in group P (P value C/T = 0.000, C/P = 0.007, T/P = 0.002). The postoperative side effects were comparable.

Conclusion:

Oral tramadol 100 mg and oral pregabalin 75 mg as premedication reduced the 24 hours postoperative morphine requirement as compared to placebo in BCCS. However, tramadol 100 mg provided superior analgesia for longer duration than pregabalin 75 mg and was associated with more side effects.

The analgesic efficacy of pregabalin for shoulder arthroscopy: A meta-analysis of randomized controlled trials

INTRODUCTION

The efficacy of pregabalin for pain management of shoulder arthroscopy remains controversial. We conduct this meta-analysis to explore the influence of pregabalin versus placebo on the postoperative pain intensity of shoulder arthroscopy.

METHODS

We have searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through November 2019 for randomized controlled trials assessing the effect of pregabalin versus placebo on pain control of shoulder arthroscopy. This meta-analysis was performed using the random-effect model.

RESULTS

Three randomized controlled trials were included in the meta-analysis. Overall, compared with control group for shoulder arthroscopy, pregabalin remarkably decreased pain scores at 0 to 1 hour (Std. MD = -0.57; 95% CI = -1.04 to -0.09; P = .02) and 12 hours (Std. MD = -0.37; 95% CI = -0.72 to -0.02; P = .04), as well as analgesic consumption (Std. MD = -1.84; 95% CI = -2.24 to -1.44; P < .00001), but showed no notable influence on pain scores at 24 hours (Std. MD = -0.54; 95% CI = -1.47 to 0.38; P = .25), nausea or vomiting (RR = 0.84; 95% CI = 0.53-1.33; P = .45), dizziness (RR = 1.14; 95% CI = 0.89-1.47; P = .30).

CONCLUSIONS

Pregabalin may benefit to pain control after shoulder arthroscopy.

Effects of Pregabalin, Nimodipine, and Their Combination in the Inhibition of Status Epilepticus and the Prevention of Death in Mice

Objectives

The current study aims to evaluate the combined antiepileptic effects of pregabalin (PGB) and nimodipine (NMD) in an acute seizure model of epilepsy in mice.

Materials and Methods

This study assessed the combined antiepileptic effects of PGB with NMD on death protection in mice. Pentylenetetrazole was used to induce seizures. Both drugs were used singly and in combination to judge anticonvulsant effects on an acute seizure model of epilepsy in mice. Diazepam (DZ) and valproate (VPT) were used as standard antiepileptic drugs.

Results

The death protection in mice by both these drugs was observed in percentage and deliberated as marked change when the outcome of the tested drug was equal to ED₅₀ of PGB and measured highly marked when the result was more than ED₅₀ for PGB. Treatment with pregabalin and nimodipine combination revealed substantial mortality protection at 30+2.5 mg/kg dose and highly marked at doses from 35+5 mg/kg to 55+15 mg/kg, these effects were superior to individual effects of PGB, showing synergism, however lesser then classic drugs valproate and diazepam.

Conclusion

NMD showed synergistic anticonvulsant effect with PGB. However, clinical studies are required to establish the effectiveness of this combination in humans.

Chronic Pain in Patients with Rheumatoid Arthritis

PURPOSE OF REVIEW

Chronic pain is highly prevalent in patients with rheumatoid arthritis (RA) and can cause various physical and psychological impairments. Unfortunately, the appropriate diagnosis of chronic pain syndromes in this population can be challenging because pain may be primary to RA-specific inflammation and/or secondary to other conditions, typically osteoarthritis (OA) and fibromyalgia (FM). This disparity further poses a clinical challenge, given that chronic pain can often be discordant or undetected with standard RA-specific surveillance strategies, including serological markers and imaging studies. In this review, we provide a robust exploration of chronic pain in the RA population with emphasis on epidemiology, mechanisms, and management strategies.

RECENT FINDINGS

Chronic pain associated with RA typically occurs in patients with anxiety, female sex, and elevated inflammatory status. Up to 50% of these patients are thought to have chronic pain despite appropriate inflammatory suppression, typically due to peripheral and central sensitization as well as secondary OA and FM. In addition to the standard-of-care management for OA and FM, patients with RA and chronic pain benefit from behavioral and psychological treatment options. Moreover, early and multimodal therapies, including non-pharmacological, pharmacological, interventional, and surgical strategies, exist, albeit with varying efficacy, to help suppress inflammation, provide necessary analgesia, and optimize functional outcomes. Overall, chronic pain in RA is a difficult entity for both patients and providers. Early diagnosis, improved understanding of its mechanisms, and initiation of early, targeted approaches to pain control may help to improve outcomes in this population.

Effects of dose titration on adherence and treatment duration of pregabalin among patients with neuropathic pain: A MarketScan database study

OBJECTIVE

To examine pregabalin dose titration and its impact on treatment adherence and duration in patients with neuropathic pain (NeP).

METHODS

MarketScan database (2009-2014) was used to extract a cohort of incident adult pregabalin users with NeP who had at least 12 months of follow-up data. Any dose augmentation within 45 days following the first pregabalin claim was defined as dose titration. Adherence (measured by medication possession ratio/MPR) and persistence (measured as the duration of continuous treatment) were compared between the cohorts with and without dose titration. Logistic regressions and Cox proportional hazards models were used to identify the factors associated with adherence (MPR ≥ 0.8) and predictors of time to discontinuation.

RESULTS

Among the 5,186 patients in the analysis, only 18% of patients had dose titration. Patients who had dose titration were approximately 2.6 times as likely to be adherent (MPR ≥ 0.8) (odds ratio = 2.59, P < 0.001) than those who did not have dose titration. Kaplan-Meier analysis shows that the time to discontinuation or switch was significantly longer among patients who had dose titration (4.99 vs. 4.04 months, P = 0.009).

CONCLUSIONS

Dose titration was associated with improved treatment adherence and persistence among NeP patients receiving pregabalin. The findings will provide valuable evidence to increase physician awareness of dose recommendations in the prescribing information and to educate patients on the importance of titration and adherence.

Aquagener Pruritus als Warnzeichen eines inneren Tumorleidens – eine Fallvorstellung und Literaturübersicht

Aquagener Pruritus (AP), d. h. Jucken, Kribbeln, Brennen nach Wasserkontakt, ist ein häufiges Symptom bei Polycythaemia vera und anderen myeloproliferativen Neoplasien, kann aber auch unabhängig davon auftreten. Wie andere Formen des Pruritus schränkt AP die Lebensqualität der Betroffenen häufig ein und kann zu einem hohen Leidensdruck führen. Zur Pathogenese existieren unterschiedliche Erklärungsansätze, jedoch kein einheitliches Konzept. Passend dazu sprechen Patienten auch nur zum Teil auf vorhandene Therapien an, die überwiegend off label sind. In dieser Literaturübersicht zum AP werden beschriebene Pathomechanismen diskutiert und mögliche Therapieformen genannt. Ein verbessertes Verständnis von AP soll dazu beitragen, dieses Symptom zu erkennen und an mögliche zugrunde liegende Erkrankungen, insbesondere an ein inneres Tumorleiden, zu denken.

Preoperative oral pregabalin for anxiety control: a systematic review

OBJECTIVE

The objective of this systematic review was to determine the effectiveness of preoperative oral pregabalin for anxiety control, the most effective dosage regimen, its impact on postoperative pain, and its adverse effects.

MATERIALS AND METHODS

A search was conducted of PubMed/Medline and clinicaltrials.gov (National Library of Medicine, Washington, DC), Scopus, Web of Science, and Cochrane databases for studies published between January 2009 and November 2018, with no language restriction. Based on PRISMA guidelines, the specific question was: is preoperative oral pregabalin effective and safe for anxiety control in patients undergoing surgery? The critical reading of retrieved studies followed questions prepared by the CASPe Network, and their methodological quality was evaluated using the Jadad Scale.

RESULTS

Twelve randomized controlled trials were selected for review. All twelve studies were trials of high quality. A dose of 75 mg preoperative oral pregabalin has been found to reduce anxiety and stabilize intraoperative hemodynamics, although a more significant improvement appears to be achieved with a single dose of 150 mg pregabalin at least 1 h before the surgery. It is not associated with any severe adverse effects.

CONCLUSION

Preoperative administration of oral pregabalin in a single dose of 150 mg appears to be effective to significantly reduce the anxiety of patients, intraoperative hemodynamic changes, and postoperative pain.

CLINICAL RELEVANCE

These findings suggest that pregabalin is useful and safe for preoperative and intraoperative anxiety control in patients undergoing surgery.

Pregabalin-associated movement disorders: A literature review

Central nervous system adverse effects are commonly reported with pregabalin (PGB). On the other hand, movement disorders (MDs) associated with this drug were rarely described. However, their occurrence could significantly affect the quality of life of PGB users. This literature review aims to evaluate the clinical epidemiological profile, pathological mechanisms, and management of PGB-associated MDs. Relevant reports in six databases were identified and assessed by two reviewers without language restriction. A total of 46 reports containing 305 cases from 17 countries were assessed. The MDs encountered were as follows: 184 individuals with ataxia, 61 with tremors, 39 with myoclonus, 8 with parkinsonism, 1 with restless legs syndrome, 1 with dystonia, 1 with dyskinesia, and 1 with akathisia. The mean age was 62 years (range: 23-94). The male sex was slightly predominant with 54.34%. The mean PGB dose when the MD occurred was 238 mg, and neuropathic pain was the most common indication of PGB. The time from PGB start to MD was < 1 month at 75%. The time from PGB withdrawal to recovery was < 1 week at 77%. All the individuals where the follow-up was reported had a full recovery. The most common management was PGB withdrawal. In the literature, the majority of the cases did not report information about timeline events, neurological examination details, or electrodiagnostic studies. The best management for all MDs is probably PGB withdrawal. If the patient is on dialysis program, perhaps an increased number of sessions will decrease recovery time. Furthermore, the addition of a benzodiazepine could accelerate recovery.

Cognitive Effects of Perioperative Pregabalin

EDITOR’S PERSPECTIVE

What We Already Know about This Topic

Perioperative administration of pregabalin has been associated with decreased postoperative pain and opioid requirements

What This Article Tells Us That Is New

This secondary analysis of data demonstrating that perioperative administration of pregabalin was associated with a reduction in opioid requirements and incisional hyperalgesia suggests that these benefits may be compromised by an increased risk of developing impaired postoperative cognitive performance

Background

Pregabalin has shown opioid sparing and analgesic effects in the early postoperative period; however, perioperative effects on cognition have not been studied. A randomized, parallel group, placebo-controlled investigation in 80 donor nephrectomy patients was previously performed that evaluated the analgesic, opioid-sparing, and antihyperalgesic effects of pregabalin. This article describes a secondary exploratory analysis that tested the hypothesis that pregabalin would impair cognitive function compared to placebo.

Methods

Eighty patients scheduled for donor nephrectomy participated in this randomized, placebo-controlled study. Pregabalin (150 mg twice daily, n = 40) or placebo (n = 40) was administered on the day of surgery and the first postoperative day, in addition to a pain regimen consisting of opioids, steroids, local anesthetics, and acetaminophen. Specific cognitive tests measuring inhibition, sustained attention, psychomotor speed, visual memory, and strategy were performed at baseline, 24 h, and 3 to 5 days after surgery, using tests from the Cambridge Neuropsychological Test Automated Battery.

Results

In the spatial working memory within errors test, the number of errors increased with pregabalin compared to placebo 24 h after surgery; median (25th, 75th percentile) values were 1 (0, 6) versus 0 (0, 1; rate ratio [95% CI], 3.20 [1.55 to 6.62]; P = 0.002). Furthermore, pregabalin significantly increased the number of errors in the stop-signal task stop-go test compared with placebo; median (25th, 75th percentile) values were 3 (1, 6) versus 1 (0, 2; rate ratio, 2.14 [1.13 to 4.07]; P = 0.020). There were no significant differences between groups in the paired associated learning, reaction time, rapid visual processing, or spatial working memory strategy tests.

Conclusions

Perioperative pregabalin significantly negatively affected subdomains of executive functioning, including inhibition, and working memory compared to placebo, whereas psychomotor speed was not changed.

Pregabalin and Dexmedetomidine Combined for Pain After Total Knee Arthroplasty or Total Hip Arthroplasty Performed Under Spinal Anesthesia

Pregabalin and dexmedetomidine have been introduced to manage postoperative pain. This study evaluated the effect of the 2 drugs combined on pain in patients undergoing total knee or hip arthroplasty. A total of 124 patients undergoing total knee or hip arthroplasty under spinal anesthesia were randomly assigned to either group C (n=31, placebo), group P (n=33, pregabalin), group PD (n=29, pregabalin and dexmedetomidine), or group D (n=31, dexmedetomidine). One hour before spinal anesthesia, patients received 150 mg of pregabalin or placebo orally, and a bolus dose of 0.5 µg/ kg of intravenous dexmedetomidine was given over 10 minutes before induction of spinal anesthesia. This was followed by a continuous infusion of 0.5 µg/kg/h or the same calculated volume of normal saline until completion of the surgery. Clinically relevant pain for 24 hours postoperatively, including time to first analgesic request, visual analog scale score, ketorolac dose, and volume of patient-controlled analgesia consumed, was recorded. Group C had significantly longer time to first analgesic request, higher visual analog scale scores at rest and on movement, higher ketorolac dose, and higher volume of patient-controlled analgesia for the first 24 hours postoperatively compared with the other groups. Although group PD and group D had less clinically relevant pain than group P, group PD and group D were not significantly different. Dexmedetomidine was more effective than pregabalin for clinically relevant pain. Pregabalin and dexmedetomidine combined had no synergic effect compared with dexmedetomidine alone. [Orthopedics. 2018; 41(6):365-370.].

Effect of preoperative pregabalin on postoperative pain after gastrectomy

Background

Pregabalin has been studied as a single or multimodal analgesic drug for postoperative pain management in different types of surgeries. We evaluated the analgesic effect of 150 mg of pregabalin in resolving post-gastrectomy pain.

Methods

Forty-four patients were randomized into two groups: a pregabalin group that received oral pregabalin (150 mg) 2 h before anesthetic induction, and a control group that received placebo tablets at the same time. Data on postoperative pain intensity (visual analog scale [VAS], at 30 min, 2 h, 4 h, and 24 h), consumption of fentanyl in patient-controlled analgesia (PCA), and the proportion of patients requiring rescue analgesics at different time intervals (0-2 h, 2-4 h, and 4-24 h) were collected during the 24 h postoperative period.

Results

The VAS scores did not show significant differences at any time point and consumption of fentanyl in PCA and the proportion of patients requiring rescue analgesics did not differ between the two groups. The groups did not differ in the occurrence of dizziness, sedation, and dry mouth.

Conclusion

A preoperative 150 mg dose of pregabalin exerts no effect on acute pain after gastrectomy.

A Validated Fluorometric Method for the Rapid Determination of Pregabalin in Human Plasma Applied to Patients With Pain

BACKGROUND

Pregabalin has been used for the treatment of pain. A clinically accepted method applied to patients with pain has not been published for the determination of pregabalin in human plasma. This study developed a fluorometric ultrahigh-performance liquid chromatography (UHPLC) method to measure pregabalin concentration in patients with pain.

METHODS

After plasma pretreatment involving protein precipitation, pregabalin and gabapentin as an internal standard were derivatized with 4-fluoro-7-nitrobenzofurazan (NBD-F) under the following reaction conditions: 1 minute, pH 10, and 60°C. The UHPLC separation was performed using a 2.3-μm particle size octadecylsilyl column. The fluorescence detector was set at excitation and emission wavelengths of 470 and 530 nm, respectively. The predose blood samples were collected from 40 patients with pain who have been treated with 75 mg of pregabalin twice daily.

RESULTS

The chromatographic run time was 1.25 minutes. No interfering peaks were observed in the blank plasma at the retention times of NBD derivatives. The calibration curve of pregabalin was linear at a range of 0.05-10 mcg/mL (r > 0.999). The lower limit of quantification was 0.05 mcg/mL. The intra-assay accuracy and precision were 98.3%-99.8% and within 4.3%, respectively. The inter-assay accuracy and precision were 103.2%-107.1% and within 4.1%, respectively. The predose plasma concentration of pregabalin in patients with pain ranged from 0.14 to 8.5 mcg/mL.

CONCLUSIONS

This study provides a validated fluorometric UHPLC method with fast analytical performance for the determination of pregabalin in human plasma. The present method could be applied to patients with pain and be used for the clinical research or therapeutic drug monitoring of pregabalin.

Oral pregabalin for acute pain relief after cervicofacial surgery: a systematic review

OBJECTIVE

The objectives of this systematic review were to unify criteria on the effectiveness of oral pregabalin to treat acute post-operative pain after cervicofacial surgery, to establish the most effective dose regimens, and to determine its effect on rescue medicine consumption and its association with adverse effects.

MATERIALS AND METHODS

PubMed/Medline (National Library of Medicine, Washington, DC), Scopus, Web of Science, and Cochrane databases were searched for studies in any language published between January 2000 and September 2016. The following question was posed, in accordance with PRISMA guidelines: Is oral pregabalin effective and safe for the relief of acute pain after cervicofacial surgery? The critical reading of the literature utilized a list of questions prepared by the CASPe Network, applying the Jadad scale for evaluation of the methodological quality of trials.

RESULTS

Eleven randomized controlled clinical trials were selected. The 11 trials obtained a score ≥ 3, considered as Ib evidence level and high quality. A single oral dose of 75-mg pregabalin before or after cervicofacial surgery alleviates pain and lessens the need for rescue analgesia consumption, while the statistical significance of these effects is higher with a single dose of 150-mg pregabalin, either before or after the surgery.

CONCLUSION

Oral pregabalin appears to significantly alleviate post-operative pain and reduce rescue analgesia consumption, with no severe adverse effects. However, the ideal dose and most effective administration regimen remain controversial issues that need to be addressed in further high-quality clinical trials.

CLINICAL RELEVANCE

These findings suggest that pregabalin may be useful for acute pain relief after cervicofacial surgery.

Synergistic anticonvulsant effects of pregabalin and amlodipine on acute seizure model of epilepsy in mice

Status epilepticus is a life threatening neurological medical emergency. It may cause serious damage to the brain and even death in many cases if not treated properly. There is limited choice of drugs for the short term and long term management of status epilepticus and the dugs recommended for status epilepticus possess various side effects. The present study was designed to investigate synergistic anticonvulsant effects of pregabalin with amlodipine on acute seizure model of epilepsy in mice. Pentylenetetrazole was used to induce acute seizures which mimic status epilepticus. Pregabalin and amlodipine were used in combination to evaluate synergistic anti-seizure effects on acute seizure model of epilepsy in mice. Diazepam and valproate were used as reference dugs. The acute anti-convulsive activity of pregabalin with amlodipine was evaluated in vivo by the chemical induced seizures and their anti-seizure effects were compared with pentylenetetrazole, reference drugs and to their individual effects. The anti-seizure effects of tested drugs were recorded in seconds on seizure characteristics such as latency of onset of threshold seizures, rearing and fallings and Hind limbs tonic extensions. The seizure protection and mortality to the animals exhibited by the drugs were recorded in percentage. Combination regimen of pregabalin with amlodipine exhibited dose dependent significant synergistic anticonvulsant effects on acute seizures which were superior to their individual effects and equivalent to reference drugs.

Analgesic efficacy of pregabalin in acute postmastectomy pain: placebo controlled dose ranging study

STUDY OBJECTIVE

We hypothesized that oral administration of a single dose of pregabalin 2 hours before modified radical mastectomy (MRM) would produce dose-related reduction in postoperative opioid consumption.

DESIGN

Prospective randomized controlled clinical trial.

SETTING

Postanesthesia care unit.

PATIENTS

One hundred twenty adult women scheduled for unilateral (MRM) with axillary evacuation.

INTERVENTIONS

Patients were randomized to receive either, placebo capsule, pregabalin 75 mg, pregabalin 150 mg, or pregabalin 300 mg.

MEASUREMENTS

The assessment parameters were the postoperative analgesic effect using visual analog scale (VAS) pain scores, the subsequent 24-hour morphine consumption, and the systemic adverse effects of pregabalin doses.

MAIN RESULTS

The VAS score at rest and movement was significantly decreased only in group P300 and group P150 in comparison to group P0 and group P75 at 0 hour (P<.01). The median (interquartile range) consumption of morphine in the first postoperative 24 hours was significantly decreased in group P300 in comparison to group P0 and group P75 (P300 vs P0: 6.5 [5-6.5] vs 20.5 [15.8-20.5] [P<.001]; P300 vs P75: 6.5 [5-6.5] vs 20 [14-20] [P<.001]), but there was no significant difference between group P300 and group P150. In addition, there was a significant decrease in consumption of morphine in group P150 in comparison to group P0 and group P75 (P150 vs P0: 7 [5-7] vs 20.5 [15.8-20.5] [P<.001]; P150 vs P75: 7 [5-7] vs 20 [14-20] [P<.001]). There were statistical significant increase in dizziness and blurred vision in group P300 in comparison to other groups (P<.05).

CONCLUSIONS

A single preoperative oral dose of pregabalin 150 mg is an optimal dose for reducing postoperative pain and morphine consumption in patients undergoing MRM.

Comparative clinical study of gabapentin and pregabalin for postoperative analgesia in laparoscopic cholecystectomy

Background:

Reduction in central sensitization by gabapentinoids that include gabapentin and pregabalin may reduce acute postoperative pain.

Aims:

The aim of this study is to evaluate postoperative analgesic benefit and efficacy in patients administered with oral gabapentin or pregabalin as premedication for laparoscopic cholecystectomy under general anesthesia.

Settings and Design:

Randomized, prospective, and comparative study.

Materials and Methods:

In this study, recruited patients were randomly allocated in three groups. Groups A, B, and C received 2 capsules of B complex, 3 capsules of 300 mg gabapentin each, and 2 capsules of 75 mg pregabalin, respectively, each in 30 patients of each group, 1 h before induction of anesthesia. Postoperative efficacy among these three groups was compared with respect to increase in duration of analgesia, reduction in postoperative pain scores, total postoperative requirements of analgesics and side effects.

Statistical Analysis:

Mean and standard deviation were calculated. Test of analysis between two groups was done by t-test and among three groups by analysis of variance, and then P value was calculated.

Results:

Pregabalin and gabapentin group had lower visual analog scale (VAS) score (P < 0.05), prolonged timing of first rescue analgesic (4.67 ± 14.79 vs. 158 ± 13.10 vs. 343.16 ± 9.69) min, and less opioid consumption (169.87 ± 20.32 vs. 116.13 ± 14.08 vs. 64.67 ± 16.69) mg compared to placebo group. Between the gabapentinoids, pregabalin group had lower VAS score, prolonged timing of first rescue analgesic, and less opioids consumption than the gabapentin group.

Conclusion:

It is concluded in this study that pregabalin group had lower VAS score, prolonged timing of first rescue analgesic, and less opioids consumption than the gabapentin group. Both gabapentinoids had better postoperative analgesic profile than placebo.

Oral pregabalin for postoperative pain relief after third molar extraction: a randomized controlled clinical trial

OBJECTIVES

The aim of this randomized controlled clinical trial was to evaluate the efficacy and safety of pregabalin administered pre- and postoperatively in patients with pain and swelling due to the surgical removal of impacted lower third molars.

MATERIALS AND METHODS

The final study sample comprised 60 volunteers (23 males and 37 females). Group 1 (n = 30) received 75 mg oral pregabalin 1 h before surgery and 1 h after surgery. Group 2 (n = 30) served as a control group and received no pregabalin. Both groups were administered with 650 mg paracetamol every 8 h for 2 days. Postoperative pain intensity and swelling were measured using a visual analog scale (VAS); pain relief experienced was reported using a four-point verbal rating scale (VRS); the rescue medication requirement, adverse effects, and global impression of the medication were also recorded.

RESULTS

No significant difference in pain intensity (VAS) was observed between the groups. However, fewer rescue medication tablets were needed by pregabalin-treated patients than by controls (p = 0.021). The frequency and intensity of adverse effects were significantly higher in pregabalin-treated patients (p < 0.001), although no serious adverse events occurred. No significant difference in the degree of swelling was observed in any measurement except that from mandibular angle to lip junction, which showed lesser inflammation in the pregabalin group at 24 h post-surgery (p = 0.011). The global opinion on the medication received was more positive in the pregabalin group (p = 0.042).

CONCLUSIONS

The administration of pregabalin reduces the requirement for rescue medication after third molar surgery and results in a more constant pain level, with fewer peaks of pain intensity.

CLINICAL RELEVANCE

These findings suggest that pregabalin may be useful to control acute postoperative pain. Adverse effects are known to be reduced at the low pregabalin dose used in our study.

Comparative study between paracetamol and two different doses of pregabalin on postoperative pain in laparoscopic cholecystectomy

Background:

Postoperative pain is the primary reason for prolonged hospital stay after laparoscopic cholecystectomy. This study compared the effect of a single oral preoperative administration of paracetamol (1 g) with 2 different doses of pregabalin (150 or 300 mg) for attenuating postoperative pain and analgesic consumption.

Materials and Methods:

Seventy-five patients, aged 18-60 years, American Society of Anesthesiologists’ physical status I and II undergoing elective laparoscopic cholecystectomy were included in this randomized controlled study. Patients were divided into three groups, 25 each to receive either oral paracetamol 1 g (group I, control group) or pregabalin 150 (group II) or 300 mg (group III), 2 h before surgery. Postoperative pain was evaluated based on visual analog scale over a period of 6 h and 1^st time for rescue analgesia. Postoperative sedation, hemodynamic changes, serum cortisol level, and side effects were also evaluated.

Results:

There was a significant decrease in mean heart rate, mean systolic blood pressure, sedation score, pain score, and delayed the first request for analgesics postoperatively in group (II) and group (III) compared to group (I) 2 h postoperatively. There was no significant difference in group (III) compared to group (II) postoperatively. The incidence of postoperative side effects was more in group (III).

Conclusion:

The single oral preoperative dose administration of pregabalin had significant opioid-sparing effect in the first 6 h after surgery, whereas side effects were more common with administration of pregabalin 300 mg.

Efficacy of Pregabalin in Acute Postoperative Pain Under Different Surgical Categories: A Meta-Analysis

The efficacy of pregabalin in acute postsurgical pain has been demonstrated in numerous studies; however, the analgesic efficacy and adverse effects of using pregabalin in various surgical procedures remain uncertain. We aim to assess the postsurgical analgesic efficacy and adverse events after pregabalin administration under different surgical categories using a systematic review and meta-analysis of randomized controlled trials.A search of the literature was performed between August 2014 to April 2015, using PubMed, Ovid via EMBASE, Google Scholar, and ClinicalTrials.gov with no limitation on publication year or language. Studies considered for inclusion were randomized controlled trials, reporting on relevant outcomes (2-, 24-hour pain scores, or 24 hour morphine-equivalent consumption) with treatment with perioperative pregabalin.Seventy-four studies were included. Pregabalin reduced pain scores at 2 hours in all categories: cardiothoracic (Hedge's g and 95%CI, -0.442 [-0.752 to -0.132], P = 0.005), ENT (Hedge g and 95%CI, -0.684 [-1.051 to -0.316], P < 0.0001), gynecologic (Hedge g, 95%CI, -0.792 [-1.235 to -0.350], P < 0.0001), laparoscopic cholecystectomy (Hedge g, 95%CI, -0.600 [-0.989 to -0.210], P = 0.003), orthopedic (Hedge g, 95%CI, -0.507 [-0.812 to -0.202], P = 0.001), spine (Hedge g, 95%CI, -0.972 [-1.537 to -0.407], P = 0.001), and miscellaneous procedures (Hedge g, 95%CI, -1.976 [-2.654 to -1.297], P < 0.0001). Pregabalin reduced 24-hour morphine consumption in gynecologic (Hedge g, 95%CI, -1.085 [-1.582 to -0.441], P = 0.001), laparoscopic cholecystectomy (Hedge g, 95%CI, -0.886 [-1.652 to -0.120], P = 0.023), orthopedic (Hedge g, 95%CI, -0.720 [-1.118 to -0.323], P < 0.0001), spine (Hedge g, 95%CI, -1.016 [-1.732 to -0.300], P = 0.005), and miscellaneous procedures (Hedge g, 95%CI, -1.329 [-2.286 to -0.372], P = 0.006). Pregabalin resulted in significant sedation in all surgical categories except ENT, laparoscopic cholecystectomy, and gynecologic procedures. Postoperative nausea and vomiting was only significant after pregabalin in miscellaneous procedures.Analgesic effects and incidence of adverse effects of using pregabalin are not equal in different surgical categories.