Is Lamotrigine Any Use For Neuropathic Pain?

Today's post from onlinelibrary.wiley.com (see link below) talks about Lamotrigine (Lamictal in Europe) as a treatment for neuropathic pain. Lamotrigine is another anti-epilepsy drug used to combat nerve pain and is becoming more and more popular as doctors run out of options for patients with stubborn symptoms. However, this study is pretty damning in its conclusions and views Lamotrigine as being no better than a placebo. This puts the patient in a difficult position, as the doctor  or specialist has prescribed it, often based on so-called 'other patient experiences'. However, drug company representatives are often the driving force behind its prescription and you need to really talk it over with your doctor before accepting it as a treatment. Using research conclusions such as this one may strengthen your argument. After that, you have to make a decision as to whether to take it or not and run the risk of your doctor feeling offended that you're rejecting his or her suggestions. However, it's your health at issue here and you deserve the best treatment. The potential side effects are also an issue to think about. May be worth asking for an alternative.

Lamotrigine for chronic neuropathic pain and fibromyalgia in adults

Philip J Wiffen*,
Sheena Derry,
R Andrew Moore

Editorial Group: Cochrane Pain, Palliative and Supportive Care Group

Published Online: 3 DEC 2013

Assessed as up-to-date: 26 NOV 2013

DOI: 10.1002/14651858.CD006044.pub4

Copyright © 2013 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.


Abstract

Background

This is an update of the original Cochrane review entitled Lamotrigine for acute and chronic pain published in Issue 2, 2007, and updated in Issue 2, 2011. Some antiepileptic medicines have a place in the treatment of neuropathic pain (pain due to nerve damage). This updated review adds no new additional studies looking at evidence for lamotrigine as an effective treatment for chronic neuropathic pain or fibromyalgia. The update uses higher standards of evidence than previously.

Objectives

To assess the analgesic efficacy of lamotrigine in the treatment of chronic neuropathic pain and fibromyalgia, and to evaluate adverse effects reported in the studies.

Search methods

We identified randomised controlled trials (RCTs) of lamotrigine for chronic neuropathic pain and fibromyalgia (including cancer pain) from MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). We ran searches for the original review in 2006, in 2011 for the first update, and subsequent searches in August 2013 for this update. We sought additional studies from the reference lists of the retrieved papers. The original review and first update included acute pain, but no acute pain studies were identified.

Selection criteria

RCTs investigating the use of lamotrigine (any dose, by any route, and for any study duration) for the treatment of chronic neuropathic pain or fibromyalgia. Assessment of pain intensity or pain relief, or both, using validated scales. Participants were adults aged 18 and over. We included only full journal publication articles.

Data collection and analysis

Two review authors independently extracted efficacy and adverse event data, and examined issues of study quality. We performed analysis using three tiers of evidence. The first tier used data where studies reported the outcome of at least 50% pain reduction from baseline, lasted at least eight weeks, had a parallel group design, included 200 or more participants in the comparison, and reported an intention-to-treat analysis. First-tier studies did not use last observation carried forward (LOCF) or other imputational methods for dropouts. The second tier used data that failed to meet this standard and second-tier results were therefore subject to potential bias.

Main results

Twelve included studies in 11 publications (1511 participants), all with chronic neuropathic pain: central post-stroke pain (1), chemotherapy-induced neuropathic pain (1), diabetic neuropathy (4), HIV-related neuropathy (2), mixed neuropathic pain (2), spinal cord injury-related pain (1), and trigeminal neuralgia (1). We did not identify any additional studies. Participants were aged between 26 and 77 years. Study duration was two weeks in one study and at least six weeks in the remainder; eight were of eight-week duration or longer.

No study provided first-tier evidence for an efficacy outcome. There was no convincing evidence that lamotrigine is effective in treating neuropathic pain and fibromyalgia at doses of 200 mg to 400 mg daily. Almost 10% of participants taking lamotrigine reported a skin rash.

Authors' conclusions

Large, high-quality, long-duration studies reporting clinically useful levels of pain relief for individual participants provided no convincing evidence that lamotrigine is effective in treating neuropathic pain and fibromyalgia at doses of about 200 to 400 mg daily. Given the availability of more effective treatments including antiepileptics and antidepressant medicines, lamotrigine does not have a significant place in therapy based on the available evidence. The adverse effect profile of lamotrigine is also of concern.

Plain language summary

Lamotrigine (an antiepileptic drug) for chronic neuropathic pain or fibromyalgia

Neuropathic pain is pain coming from damaged nerves. It is different from pain messages carried along healthy nerves from damaged tissue (a fall, or cut, or arthritic knee). Neuropathic pain is treated by different medicines than pain from damaged tissue. Medicines like paracetamol or ibuprofen are not effective in neuropathic pain, while medicines that are sometimes used to treat depression or epilepsy can be very effective in some people with neuropathic pain. Our understanding of fibromyalgia (a condition of persistent, widespread pain and tenderness, sleep problems, and fatigue) is lacking, but fibromyalgia can respond to the same medicines as neuropathic pain.

Lamotrigine is a medicine used to treat epilepsy, and so might be a useful medicine for neuropathic pain or fibromyalgia.

On 26 November 2013 we performed searches to look for clinical trials where lamotrigine was used to treat neuropathic pain or fibromyalgia. We found 12 studies of reasonable quality that tested lamotrigine against placebo for a number of weeks. Almost half of the 1511 people in the studies had painful limbs because of damaged nerves caused by diabetes, and seven different painful neuropathic conditions were examined. No studies looked at fibromyalgia.

Lamotrigine did not help the pain, and was no different from placebo except in causing more side effects. Adverse events were more frequent with lamotrigine than placebo, with rash in 1 person in 27.

http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006044.pub4/abstract