Inconsistent Benefit vs Harm of Skeletal Muscle Relaxants for Chronic Pain Syndromes

CLINICAL QUESTION

Are skeletal muscle relaxants, such as baclofen, tizanidine, and cyclobenzaprine, safe and effective for the long-term treatment of chronic pain in adults?

BOTTOM LINE

The review found that the long-term use of skeletal muscle relaxants is no better than placebo for low back pain, fibromyalgia, and headaches. Evidence is minimal for beneficial relief from trigeminal neuralgia, painful nocturnal cramps, and neck pain. Because of the common adverse effects of drowsiness and dizziness, clinicians should deprescribe these medications in patients whose pain-related goals are not being met. (Level of Evidence = 2a)

SYNOPSIS

The investigators searched multiple databases, including Medline, EMBASE, Web of Science, and Cochrane, and other reviews and bibliographies for studies that evaluated the long-term use of skeletal muscle relaxants for chronic pain syndromes. Eligible studies included randomized controlled trials (RCTs) and observational studies on the use of skeletal muscle relaxants for at least 4 weeks in adults with painful syndromes lasting 3 months or longer. The authors included articles published in English, Spanish, and Italian. Two individuals independently screened studies for inclusion criteria and methodologic quality using standard scoring systems. Disagreements were resolved by consensus discussion with a third reviewer.