Efficacy of memantine in the treatment of fibromyalgia: A double-blind, randomised, controlled trial with 6-month follow-up

Abstract

Fibromyalgia (FM) is a prevalent and disabling chronic disease. Recent studies have found elevated levels of glutamate in several brain regions, leading to hypotheses about the usefulness of glutamate-blocking drugs such as memantine in the treatment of FM. The aim of this study was to evaluate the efficacy of memantine in the treatment of pain and other clinical variables (global function, clinical impression, depression, anxiety, quality of life) in FM patients. A double-blind, parallel randomised controlled trial was developed. A total of 63 patients diagnosed with FM were recruited from primary health care centres in Zaragoza, Spain. Memantine was administered at doses of 20mg/d after 1 month of titration. Assessments were carried out at baseline, posttreatment, and 3- and 6-month follow-up. Compared with a placebo group, memantine significantly decreased ratings on a pain visual analogue scale (Cohen's d=1.43 at 6 months) and pain measured with a sphygmomanometer (d=1.05). All other secondary outcomes except anxiety also improved, with moderate-to-large effect sizes at 6 months. Compared with placebo, the absolute risk reduction obtained with memantine was 16.13% (95% confidence interval=2.0% to 32.6%), and the number needed to treat was 6.2 (95% confidence interval=3 to 47). Tolerance was good, with dizziness (8 patients) and headache (4 patients) being the most frequent side effects of memantine. Although additional studies with larger sample sizes and longer follow-up times are needed, this study provides preliminary evidence of the utility of memantine for the treatment of FM.

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“…A number of studies have demonstrated that the incidence of adverse effects related to the drug is low [1,8,[16][17]27]. The fact that the drug is well-tolerated has been shown in our study as well.…”

“…Several researches have been performed to highlight the potential role of glutamate antagonists in the treatment of fibromyalgia [18,[26][27][28]. According to a randomized controlled clinical trial conducted on 25 patients with fibromyalgia to evaluate the efficacy of Memantine on metabolite levels in the brain, patients treated with Memantine exhibited an increase in cerebral metabolism of glutamate and other metabolites, which suggests its potential role in the treatment of fibromyalgia [26].…”

“…In a six-month long randomized controlled trial carried out in Spain on 63 patients with fibromyalgia who were administered 20mg/day of Memantine after 1 month of titration, significant improvement in pain, quality of life, global functioning and depression was noted [27]. In the present study, all of our patients reported improvement in their physical functioning at the final follow-up visit at 3 months and almost all (96.7%) patients reported improvement in pain and waking up well rested in the morning after taking Memantine.…”

Efficacy of Memantine in Treating Patients with Dementia and Fibromyalgia

“…Several studies have shown the efficacy of Memantine in improving symptoms of depression in fibromyalgia patients [18,27]. 86.7% of the patients in our study reported less or none symptoms of depression at the final followup visit at three months.…”

Treatment of fibromyalgia

“…42 Pure mu-opioid receptor agonists, such as codeine, fentanyl and oxycodone, are contraindicated because of poor clinical response and increased risk of opioid-induced hyperalgesia. 40 There is no trial evidence of efficacy for paracetamol used alone and there is weak evidence that non-steroidal anti-inflammatory drugs are ineffective.…”