Drug safety evaluation of pregabalin

Managing delayed or missed pregabalin doses in patients with focal epilepsy: a Monte Carlo simulation study

BACKGROUND

Delayed or missed doses are inevitable in epilepsy pharmacotherapy. The current remedial measures recommended by the United States Food and Drug Administration (FDA) for non-adherence are generic and lack clinical evidence.

AIM

To assess remedial strategies for delayed or missed pregabalin doses in patients with epilepsy using Monte Carlo simulations.

METHOD

Monte Carlo simulations were performed using a published population pharmacokinetic model for pregabalin. The applicability of five proposed remedial regimens as well as FDA recommendations was evaluated by simulating various poor adherence scenarios in eight populations, including those with renal dysfunction.

RESULTS

All proposed remedial strategies were associated with delay duration and renal function. When delays are relatively short, an immediate regular dose is advised. The cut-off time points for taking the regular dose as a remedial regimen were 1, 2, 4, and 12 h for patients with mild renal impairment and normal renal function, moderate renal impairment, severe renal impairment, and end-stage renal disease, respectively. However, when delay aligns closely with a dosing interval, a regular dose combined with a partial dose proves effective. Generally, supplementing 1.3-fold the regular dose at the next scheduled time adequately compensates for the missed dose.

CONCLUSION

Model-based simulations provided quantitative evidence for the effectiveness and feasibility of remedial strategies for missed or delayed pregabalin doses.

Recognizing and Treating Major Depression in Fibromyalgia: A Narrative Primer for the Non-Psychiatrist

Fibromyalgia (FM) affects 2% to 8% of the general population. FM patients often experience self-stigma and feel rejected by healthcare providers and families, resulting in isolation and distressing symptoms of pain, fatigue, and poor cognitive functioning, increasing the risk of depressive symptoms. Major Depressive Disorder (MDD) is the most common comorbidity in FM patients (Any depression: 43%; MDD: 32%). Genome-wide association studies (GWAS) have identified a common genetic risk loci for major depression and fibromyalgia. Given that even minor symptoms of depression worsen the outcomes of FM patients, clinicians are challenged to identify and manage depression in these patients. However, due to overlapping symptoms, limited screening, and contamination bias, MDD often goes undiagnosed and presents a critical challenge. Unrecognized and untreated MDD in FM patients can exacerbate fatigue, sleep disturbances, and pain, reduce physical functioning, and increase the risk of developing comorbid conditions, such as substance abuse and cardiovascular disease. These comorbidities are associated with a lower treatment response rate, a higher dropout rate, and a greater risk of relapse. Clinicians may effectively identify and treat MDD in FM patients with appropriate pharmacologic agents combined with aerobic exercise and cognitive-behavioral therapies for core FM symptoms, thus significantly reducing symptom severity for both MDD and FM. Such a comprehensive approach will result in a much-improved quality of life. MedLine content was searched via PubMed to identify eligible articles between 1995 and 2023 using search terms fibromyalgia, major depressive disorder, and treatment of depression in fibromyalgia, and the most current information is presented. In this primer for clinicians caring for FM patients, we describe clinically relevant pharmacologic and non-pharmacologic management approaches for treating MDD in FM patients.

Gabapentin and Pregabalin Use and Association with Adverse Outcomes among Hemodialysis Patients

Background Gabapentin and pregabalin are used to manage neuropathic pain, pruritus, and restless legs syndrome in patients on hemodialysis. These patients may be especially predisposed to complications related to these agents, which are renally cleared, but data regarding the risk thereof are lacking.Methods From the US Renal Data System, we identified 140,899 Medicare-covered adults receiving hemodialysis with Part D coverage in 2011. Using Cox regression models in which we adjusted for demographics, comorbidities, duration of exposure, number of medications, and use of potentially confounding concomitant medications, we investigated the association between gabapentin and pregabalin, modeled as separate time-varying exposures, and time to first emergency room visit or hospitalization for altered mental status, fall, and fracture. We evaluated risk according to daily dose categories: gabapentin (>0-100, >100-200, >200-300, and >300 mg) and pregabalin (>0-100 and >100 mg).Results In 2011, 19% and 4% of patients received gabapentin and pregabalin, respectively. Sixty-eight percent of gabapentin or pregabalin users had a diagnosis of neuropathic pain, pruritus, or restless legs syndrome. Gabapentin was associated with 50%, 55%, and 38% higher hazards of altered mental status, fall, and fracture, respectively, in the highest dose category, but even lower dosing was associated with a higher hazard of altered mental status (31%-41%) and fall (26%-30%). Pregabalin was associated with up to 51% and 68% higher hazards of altered mental status and fall, respectively.Conclusions Gabapentin and pregabalin should be used judiciously in patients on hemodialysis, and research to identify the most optimal dosing is warranted.

Intravenous buprenorphine/naloxone and concomitant oral pregabalin misuse: a case report

Opioid misuse and dependence are major medical and social concerns worldwide. Buprenorphine/naloxone combination (BNC) is a drug that has misuse potential and is used to treat opioid dependence, including buprenorphine and naloxone. Buprenorphine shows its pharmacological effects by binding to opioid receptors. Buprenorphine is a partial agonist and has smaller maximal effects compared to those of full agonists (heroin, methadone). Naloxone is a non-selective opiate antagonist added to buprenorphine for the prevention of intravenous diversion. BNC is used in the treatment of opioid dependence for detoxification and maintenance. The drug should be used as a sublingual film tablet. Pregabalin is used in the treatment of neuropathic pain, epilepsy and anxiety disorders. It is increasingly being reported as possessing a potential for misuse. In this article, we present a case of intravenous BNC and concomitant oral pregabalin misuse that developed in a monitored and treated patient for the reason of opioid dependence.

Gabapentinoids for chronic low back pain: a protocol for systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Chronic low back pain (CLBP) is a common condition and causes significant pain, distress and disability across the world. It is multifactorial in aetiology and is challenging to manage. Although the underlying mechanism of pain is predominantly non-specific, many argue that there is a substantial neuropathic pain element. Neuropathic pain is more severe, with significant disability. Gabapentinoids, including gabapentin and pregabalin, have proven efficacy in some neuropathic pain conditions. Despite no clear evidence, a substantial population of patients with CLBP are treated with gabapentinoids.

OBJECTIVES

We aim to assess whether the use of gabapentinoids is effective and safe in the treatment of predominant CLBP, by conducting a systematic review and meta-analysis of randomised control trials (RCTs).

METHODOLOGY

We will search the databases of MEDLINE, EMBASE and Cochrane for RCTs published in English language and have used gabapentinoids for the treatment of CLBP. Study selection and data extraction will be performed independently by paired reviewers using structured electronic forms, piloted between pairs of reviewers. The review outcomes will be guided by Initiative on Methods, Measurement and Pain Assessment in Clinical Trials guidelines, with pain relief as the primary outcome. We propose to carry out meta-analysis if there are three or more studies in a particular outcome domain, using a random effects model. Pooled outcomes will be reported as weighted mean differences or standardised mean differences and risk ratios with their corresponding 95% CIs, for continuous outcomes and dichotomous outcomes, respectively. Rating of quality of evidence will be reported using GRADE summary of findings table.

DISCUSSION

The proposed systematic review will be able to provide valuable evidence to help decision-making in the use of gabapentinoids for the treatment of CLBP. This will help advance patient care and potentially highlight limitations in existing evidence to direct future research.

ETHICS AND DISSEMINATION

Being a systematic review, this study would not necessitate ethical review and approval. We plan to report and publish our study findings in a high impact medical journal, with online access.

TRIAL REGISTRATION NUMBER

CRD42016034040.

Alpha2delta ligands, gabapentin, pregabalin and mirogabalin: a review of their clinical pharmacology and therapeutic use

INTRODUCTION

The first two alpha₂delta ligands - gabapentin (GBP) and pregabalin (PGB) - were initially synthesized as antiepileptics; however, they were later also found to be useful for the treatment of additional conditions. Areas covered: Relevant publications describing potential underlying mechanisms, clinical pharmacokinetics/pharmacokinetics, and clinical efficacy and safety of these drugs in various disease conditions were searched in PubMed and Scopus and included in this review. Expert commentary: GBP and PGB are effective for the treatment neuropathic pain, fibromyalgia and epilepsy; in addition, they may be useful for the reduction of postoperative pain. PGB is also effective for the treatment of generalized anxiety disorder and GBP for the treatment of restless legs syndrome. GBP may be considered a treatment option for pain associated with Guillain-Barré Syndrome and phantom limb and for the management of uremic pruritus. Mirogabalin (MGB), recently developed, is being investigated for the treatment of peripheral neuropathic pain and fibromyalgia, showing promising results in patients with diabetic peripheral neuropathy. Their most frequent adverse reactions are of neuropsychiatric nature and include fatigue, dizziness, sedation, somnolence, and ataxia; peripheral edema and weight gain are also frequently described. Pharmacokinetic interactions are scarce; however, pharmacodynamic interactions have been described in association with drugs with CNS-depressant effects.

A Decade of Gabapentinoid Misuse: An Analysis of the European Medicines Agency's 'Suspected Adverse Drug Reactions' Database

INTRODUCTION

The gabapentinoids pregabalin and gabapentin are being increasingly prescribed for a range of clinical conditions. Recently, although gabapentinoids at therapeutic dosages may present with low addictive liability levels, cases of misuse and rising numbers of related fatalities have been reported.

OBJECTIVES

The aim of the study was to identify and assess cases of gabapentinoid misuse or dependence as reported to the European Medicines Agency's EudraVigilance database, to identify the magnitude of this problem and the characteristics of these reactions.

METHODS

All spontaneous reports of both gabapentin- (2004-2015) and pregabalin- (2006-2015) related misuse/abuse/dependence were retrieved. A descriptive analysis by source, sex, age, and type of report was performed.

RESULTS

From the EudraVigilance database 7639 (6.6 % of a total of 115,616) and 4301 (4.8 % of 90,166) adverse drug reaction reports of misuse/abuse/dependence were, respectively, associated with pregabalin and gabapentin, with an overall reporting frequency increasing over time. For both molecules, subjects typically involved were female adults. A total of 27 and 86 fatalities, respectively, associated with pregabalin and gabapentin, and mostly in combination with opioids, were identified. Analysis of proportional reporting ratios for drug abuse/dependence/intentional product misuse values seem to indicate that these adverse drug reactions were more frequently reported for pregabalin (1.25, 1.39, and 1.58, respectively) compared with gabapentin.

CONCLUSIONS

Despite data collection/methodological approach limitations, the present data seem to suggest that gabapentinoid misuse may be a cause for concern, especially in patients with a history of substance misuse. Hence, healthcare professionals should be vigilant when prescribing these molecules.

3-[4-(3-Trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one and pregabalin attenuate tactile allodynia in the mouse model of chronic constriction injury

PURPOSE

There is a strong medical demand to search for novel, more efficacious and safer than available, analgesics for the treatment of neuropathic pain. This study investigated antinociceptive activity of intraperitoneally administered 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one (LPP1) and pregabalin in the chronic constriction injury (CCI) model of neuropathic pain in mice and evaluated these drugs' influence on motor coordination. In addition, microscopic examinations of the sciatic nerve were performed to assess, if a surgical method or drug treatment caused changes in the structure of this nerve. Moreover, the alterations of nerve growth factor (NGF) content after drug treatment were assessed.

METHODS

Antiallodynic and antihyperalgesic activities of LPP1 and pregabalin were assessed in the von Frey and hot plate tests. Motor-impairing properties were evaluated in the rotarod test. Microscopic examinations of the sciatic nerve were performed using electron microscope. In immunohistochemical assays the content of NGF in the sciatic nerve after single or repeated administration of test drugs was assessed.

RESULTS

Microscopic examinations of the sciatic nerve revealed ultrastructural changes in nerve fibers indicating for neurodegenerative processes induced by CCI. Seven days after CCI surgery LPP1 and pregabalin reduced tactile allodynia in von Frey test (ED50 values were 1.5 and 15.4 mg/kg, respectively). None of the test drugs at dose range 0.5-100 mg/kg induced motor deficits in the rotarod test. In immunohistochemical assays repeated doses of pregabalin and LPP1 elevated NGF content.

CONCLUSIONS

LPP1 has antiallodynic properties and is an interesting lead structure in the search for novel analgesics used in neuropathic pain.

Pregabalin for painful diabetic peripheral neuropathy: strategies for dosing, monotherapy vs. combination therapy, treatment-refractory patients, and adverse events

OBJECTIVE

Primary care physicians face significant challenges when treating painful diabetic peripheral neuropathy (pDPN). The physician must determine the best dosing strategy, consider the use of combination therapy, and decide how best to treat patients who have responded poorly to other treatment options in the past. With a focus on these issues, this paper will review the use of pregabalin for the treatment of pDPN in order to provide physicians with clinical data needed to develop, in combination with real-world prescribing data, effective treatment strategies for this common but challenging type of pain.

RESEARCH DESIGN AND METHODS

A formal PubMed search, along with a search of unpublished data from the Pfizer clinical trial database, was used to identify papers describing results from clinical trials of pregabalin in patients with pDPN. Papers were selected for inclusion in the review if they addressed the use of pregabalin in the context of a head-to-head treatment comparison, use in refractory patients, or as part of combination therapy. A discussion of pregabalin dosing and adverse events is also presented.

CONCLUSIONS

There is some difference with respect to the maximum approved dose of pregabalin for the treatment of pDPN in the United States (300 mg/day) and European Union (600 mg/day), though clinical data demonstrate that pregabalin doses >300 mg/day may be beneficial in some patients. Pregabalin has shown efficacy (and is approved) as a monotherapy for pDPN, although several guidelines recommend combination therapy for challenging cases. However, evidence to support combination therapy is sparse and the decision of monotherapy vs. combination therapy should be at the physician's discretion. There are data demonstrating the efficacy of pregabalin in some patients with pDPN who have not responded to other pharmacological treatments, including those unresponsive to treatment with gabapentin. Clinical guidelines acknowledge the paucity of head-to-head data among treatment options, but consistently recommend pregabalin as a first-tier treatment for pDPN.

A comprehensive drug safety evaluation of pregabalin in peripheral neuropathic pain

Pregabalin is a commonly used therapy currently recommended as first-line treatment for a number of neuropathic pain (NeP) conditions. Since licensure, a number of clinical trials of pregabalin in different NeP conditions have been completed from which additional data on safety and tolerability can be drawn. In this analysis, patient-level data from 31 randomized clinical trials of pregabalin in peripheral NeP sponsored by Pfizer were pooled and assessed for incidence of adverse events (AEs). Incidence by age, disease condition, and race, together with risk differences and time to onset and resolution of AEs, was assessed. In total, 7,510 patients were included: 4,884 on pregabalin (representing 805 patient-years treatment) and 2,626 on placebo. Pregabalin vs. placebo risk analysis identified 9 AEs with a risk difference, for which the lower limit of the 95% confidence interval (CI) was > 1%: dizziness (risk difference [95% CI]: (17.0 [15.4 to 18.6]), somnolence (10.8 [9.5 to 12.1]), peripheral edema (5.4 [4.3 to 6.4]), weight increase (4.7 [3.9 to 5.5]), dry mouth (2.9 [2.1 to 3.8]), constipation (2.3 [1.5 to 3.2]), blurred vision (2.2 [1.6 to 2.9]), balance disorder (2.0 [1.5 to 2.5]), and euphoric mood (1.6 [1.2 to 2.0]). The most common AEs, dizziness and somnolence, typically emerged within the first 1 to 2 weeks of treatment and resolved 1 to 2 weeks later, without resulting in cessation of treatment. The data from this review provide information, indicating which AEs may be expected in patients treated with pregabalin, and suggest that careful dose titration to the highest tolerable dose is the most appropriate approach in clinical practice.

Joint medicine-information and pharmacovigilance services could improve detection and communication about drug-safety problems

Background

RELIS is a Norwegian network of four regional medicine-information and pharmacovigilance centers where pharmacists and clinical pharmacologists provide feedback to health care professionals in spontaneous drug-related questions and adverse drug-reaction (ADR) reports published in a question–answer pair (QAP) database (the RELIS database) and the Norwegian ADR database, respectively.

Objective

To describe the potential of RELIS’s dual service to improve detection and communication of drug-safety problems.

Materials and methods

We searched the RELIS database for QAPs about ADRs with use of the Norwegian ADR database as a reference. We also searched the Norwegian ADR database for reports that used the RELIS database as a reference. Both searches were limited to the years 2003–2012. We then selected the example of pregabalin and drug abuse after the marketing of Lyrica in Norway in September 2004 to illustrate RELIS’s potential to detect new drug-safety information through a limited number of QAPs and ADR reports.

Results

A total of 5,427 (26%) of 21,071 QAPs in the RELIS database concerned ADRs. QAPs from this database were used as references in 791 (4%) of a total of 22,090 reports in the Norwegian ADR database. The Norwegian ADR database was used as a reference in 363 (7%) of 5,427 QAPs that concerned ADRs. Between September 2004 and September 2008, RELIS received eleven questions and 13 ADR reports about suspicion of Lyrica (pregabalin) and different aspects of abuse.

Conclusion

RELIS processes data through two databases that facilitate communication about ADRs. Our service also has the potential to detect new drug-safety problems with a limited number of questions and ADR reports.

Pregabalin: latest safety evidence and clinical implications for the management of neuropathic pain

Used mainly for the management of neuropathic pain, pregabalin is a gabapentinoid or anticonvulsant that was initially developed as an antiepileptic agent. After more than a decade of experience with pregabalin, experience and studies have shown that the adverse effect profile of pregabalin is well tolerated for the management of neuropathic pain and other conditions. Its use is associated with benign central nervous system and systemic adverse effects, and there are very limited metabolic, idiosyncratic or known teratogenic adverse effects. Along with its efficacy in particular neuropathic pain conditions, pregabalin's safety led it to be one of the first pharmacotherapies considered for the management of neuropathic pain. This review discusses the use of pregabalin as well as its potential adverse effects, including the most commonly noted features of sedation, dizziness, peripheral edema and dry mouth. Although other adverse effects may occur, these appear to be uncommon. The review also discusses the clinical implications of pregabalin's use for the clinician.

Neuroprotective activity of thioctic acid in central nervous system lesions consequent to peripheral nerve injury

Peripheral neuropathies are heterogeneous disorders presenting often with hyperalgesia and allodynia. This study has assessed if chronic constriction injury (CCI) of sciatic nerve is accompanied by increased oxidative stress and central nervous system (CNS) changes and if these changes are sensitive to treatment with thioctic acid. Thioctic acid is a naturally occurring antioxidant existing in two optical isomers (+)- and (−)-thioctic acid and in the racemic form. It has been proposed for treating disorders associated with increased oxidative stress. Sciatic nerve CCI was made in spontaneously hypertensive rats (SHRs) and in normotensive reference cohorts. Rats were untreated or treated intraperitoneally for 14 days with (+/−)-, (+)-, or (−)-thioctic acid. Oxidative stress, astrogliosis, myelin sheets status, and neuronal injury in motor and sensory cerebrocortical areas were assessed. Increase of oxidative stress markers, astrogliosis, and neuronal damage accompanied by a decreased expression of neurofilament were observed in SHR. This phenomenon was more pronounced after CCI. Thioctic acid countered astrogliosis and neuronal damage, (+)-thioctic acid being more active than (+/−)- or (−)-enantiomers. These findings suggest a neuroprotective activity of thioctic acid on CNS lesions consequent to CCI and that the compound may represent a therapeutic option for entrapment neuropathies.

Weight change, genetics and antiepileptic drugs

Weight gain caused by antiepileptic drugs (AEDs) constitutes a serious problem in the management of people with epilepsy. AEDs associated with weight gain include sodium valproate, pregabalin and vigabatrin. Excessive weight gain can lead to non-compliance with treatment and to an exacerbation of obesity-related conditions. The mechanisms by which AEDs cause weight gain are not fully understood. It is likely that weight change induced by some AEDs has a genetic underpinning, and recent developments in DNA sequencing technology should speed the understanding, prediction and thus prevention of serious weight change associated with AEDs. This review focuses on the biology of obesity in the context of AEDs. Future directions in the investigations of the mechanism of weight change associated with these drugs and the use of such knowledge in tailoring the treatment of specific patient groups are explored.

The application of support vector regression for prediction of the antiallodynic effect of drug combinations in the mouse model of streptozocin-induced diabetic neuropathy

Drug interactions are an important issue of efficacious and safe pharmacotherapy. Although the use of drug combinations carries the potential risk of enhanced toxicity, when carefully introduced it enables to optimize the therapy and achieve pharmacological effects at doses lower than those of single agents. In view of the development of novel analgesic compounds for the neuropathic pain treatment little is known about their influence on the efficacy of currently used analgesic drugs. Below we describe the preliminary evaluation of support vector machine in the regression mode (SVR) application for the prediction of maximal antiallodynic effect of a new derivative of dihydrofuran-2-one (LPP1) used in combination with pregabalin (PGB) in the streptozocin-induced neuropathic pain model in mice. Based on SVR the most effective doses of co-administered LPP1 (4mg/kg) and PGB (1mg/kg) were predicted to cause the paw withdrawal threshold at 6.7g in the von Frey test. In vivo for the same combination of doses the paw withdrawal was observed at 6.5g, which confirms good predictive properties of SVR.

Evaluation of analgesic, antioxidant, cytotoxic and metabolic effects of pregabalin for the use in neuropathic pain

OBJECTIVE

The aim of this research was to evaluate analgesic, antioxidant, metabolic, and cytotoxic effects of pregabalin (PGB), which is widely applied for the treatment of neuropathic pain syndromes in diabetic patients.

METHODS

We used the streptozotocin (STZ) model of painful diabetic neuropathy (PDN) in mice and we measured the effect of intraperitoneally administered PGB on tactile and thermal nociceptive thresholds in the von Frey and hot plate assays, respectively. The influence of PGB on the motor coordination of diabetic animals was investigated in the rotarod test. In vitro in HepG2 and 3T3-L1 cell lines cytotoxicity of PGB, its influence on glucose utilization, and lipid accumulation were assessed. The antioxidant capacity of PGB was evaluated spectrophotometrically using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method.

RESULTS

Pregabalin was a very efficacious antiallodynic and analgesic drug capable of increasing the pain thresholds for tactile allodynia and thermal hyperalgesia in diabetic mice. In the von Frey test at a dose of 30 mg/kg it elevated the pain threshold for 168% versus diabetic control and in the hot plate test this dose prolonged the latency time to pain reaction for 130% versus control value of diabetic mice. No motor deficits were observed in PGB-treated diabetic animals. In vitro PGB did not influence glucose utilization or lipid accumulation. No antioxidant or cytotoxic effects of PGB were observed at concentrations 1-100 μM.

DISCUSSION AND CONCLUSION

Our experiments demonstrated significant antiallodynic and analgesic properties of PGB in mice. In vitro studies showed that this drug is metabolically neutral. It did not cause motor coordination impairments in diabetic animals either. These effects might be of great importance for diabetic patients.

A back translation of pregabalin and carbamazepine against evoked and non-evoked endpoints in the rat spared nerve injury model of neuropathic pain

The purpose of the present study was twofold. First to characterize endpoints distinct to the reflexive responses to sensory stimuli typically used in neuropathic pain models. A second aim was to evaluate two clinically approved drugs carbamazepine (Tegretol) and pregabalin (Lyrica) against these endpoints with the purpose to backtranslate from the clinical to preclinical setting. The selected neuropathic pain model was the spared nerve injury (SNI) model and the endpoints were burrowing and measures of paw posture in Sprague Dawley rats. As previously described, SNI surgery produced a robust heightened sensitivity to tactile and thermal (cold) stimuli. SNI surgery also produced robust decreases in burrowing and affected multiple measures of paw position. There was no correlation between magnitude of change in burrowing and sensory allodynia within SNI operated rats. Pregabalin (10-30 mg/kg IP) produced a reliable reversal of both tactile and cold allodynia and also the burrowing deficit, with minimal effect on neurological function evaluated using rotorod, beam walking and open field activity. Pregabalin did not affect any measure of paw position. Pharmacokinetic studies conducted in satellite animals identified plasma levels of pregabalin at the 10 mg/kg IP dose to be equivalent to clinically efficacious levels recorded in neuropathic patients (3-6 μg/ml). In contrast carbamazepine (10-60 mg/kg IP) had only a very modest effect against a reflexive (tactile) measure, and no effect against the burrowing deficit. Carbamazepine also affected various measures of neurological function, complicating interpretation of the reflexive measure. Measurement of burrowing appears to detect a behavioural deficit associated with the SNI model, that may be attenuated by pregabalin but not carbamazepine. Overall the present findings support an advantage of pregabalin over carbamazepine in terms of both efficacy and tolerability which is consistent with clinical experience. The inclusion of additional endpoints beyond traditional reflexive behaviours further supports the value of rodent neuropathic pain models, such as the SNI, as behavioural assays to detect new chemical entities to treat this pain condition.