A perspective paper the International Journal of Clinical Practice suggests that antidepressants may assist in alleviating painful conditions, such as osteoarthritis. The paper adds that antidepressants may also result in fewer side effects than traditionally prescribed drug regimes, such as anti-inflammatories.

According to a recent news release, the antidepressent duloxetine received the US Food and Drug Administration (FDA) approval in 2010 for use with chronic musculoskeletal pain, including osteoarthritis (OA). Authors Leslie Citrome, MD, and Amy Weiss-Citrome, MD, analyzed two randomized double-blind, placebo controlled clinical trials that formed the basis for the FDA approval.

The authors report that the study results were analyzed using number needed to treat (NNT) and number needed to harm (NNH). The results indicated that when compared to a placebo tablet, using data from two FDA approval studies, the NNT was six. The authors explain that this finding suggested six patients would need to be treated with duloxetine rather than the placebo before encountering one additional patient experiencing improvement in pain using a composite measure that brings together a number of indicators of efficacy. 

The study’s findings over a 13-week duration reportedly paralleled other studies of non-steroidal anti-inflammatory drugs (NSAIDs). The prior studies indicated NNT as five for etodolac after 4 weeks and four for tenoxicam after 8 weeks. 

The study reports that the side effects of the various drugs were considered and ultimately exhibited that when duloxetine was used on its own for 13 weeks, it had several advantages over NSAISDs. The results indicate that the most common effects of duloxetine, which included nausea, fatigue, and constipation, were small compared to the placebo, resulting in NNHs of 16, 17, and 19 respectively. The authors note that these results suggest 16, 17, and 19 patients would need to be treated with dulozetine in place of the placebo before encountering one additional patient experiencing nausea.

The news release also notes that the authors examined a recent study’s findings that encompassed a 10-week double-blind trial of 524 patients with OA of the knee. The new study’s results suggested that patients who were treated with a combination of duloxetine and NSAIDs reported greater pain reduction than the control group who took a NSAID with a placebo. The results also indicate that the NNT for the outcome of substantial improvement in pain compared to the combination treatment using NSAIDs alone was six.

Based on their analysis, the authors recommend that clinicians managing patients suffering from osteoarthritis consider also prescribing adjunctive antidepressants.

Source: International Journal of Clinical Practice