(HealthDay News)  Neuromodulators are superior to placebo for reducing pain in patients with rheumatoid arthritis (RA), but treatment is associated with adverse events; whereas muscle relaxants show no benefit for improving pain in RA, according to two reviews published online Jan. 18 in the Cochrane Database of Systematic Reviews.

Bethan L. Richards, MBBS, from the Royal Prince Alfred Hospital in Camperdown, Australia, and colleagues investigated the efficacy and safety of neuromodulators for pain management in RA. Four trials were identified, comprising 141 patients, which evaluated oral nefopam, topical capsaicin, and oromucosal cannabis; all trials had a high risk of bias. Analyses showed significant pain reduction for nefopam over placebo after two weeks, but it was associated with significantly more adverse events. There was a significantly greater reduction in pain with topical capsaicin versus placebo. A small but significant effect with cannabis was seen in a low-quality trial, but there were more adverse events with cannabis.

In a second review, Richards and colleagues evaluated the literature to determine the efficacy and safety of muscle relaxants for management of pain in patients with RA. Six trials comprising 126 participants were included, all of which had high risk of bias. The trials evaluated benzodiazepine, diazepam, triazolam, and zopiclone. The trials did not show any benefit of muscle relaxants over placebo on pain intensity, function, or quality of life.

“Given the large number of people with RA, and the debilitating [effect] that the disease has on their lives, it is disappointing that no high-quality studies have been carried out on these drugs in this patient group,” Richards said in a statement.

Abstract 1
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Abstract 2
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