What is the recommended treatment for muscle pain with muscle relaxers?

Muscle Relaxants for Muscle Pain Treatment

Muscle relaxants should be used only for short-term treatment (up to 2-3 weeks) of acute muscle pain as an adjunct to rest and physical therapy, as they have not been proven effective for chronic pain and carry significant risks of adverse effects. 1

First-Line Treatment Options

• For acute musculoskeletal pain, non-opioid analgesics such as acetaminophen and NSAIDs should be considered first-line treatment before muscle relaxants due to their more favorable safety profile 2
• When muscle spasm is clearly associated with acute, painful musculoskeletal conditions, muscle relaxants may be considered as a short-term adjunctive therapy 1

Appropriate Use of Muscle Relaxants

• Muscle relaxants should only be used for short periods (up to 2-3 weeks) as there is inadequate evidence for effectiveness with prolonged use 1
• These medications should be used as an adjunct to rest and physical therapy, not as standalone treatment 1
• Muscle relaxants have not been found effective in treating spasticity associated with cerebral or spinal cord disease 1

Specific Muscle Relaxants and Their Considerations

• Cyclobenzaprine is one of the most studied muscle relaxants with evidence supporting its effectiveness for acute muscle pain, but it is structurally similar to tricyclic antidepressants and carries anticholinergic side effects including drowsiness and dry mouth 3, 4
• Metaxalone has fewer reported side effects compared to other muscle relaxants but still requires caution 5
• Carisoprodol raises significant concerns due to its potential for physical and psychological dependence and has been removed from the European market due to abuse concerns 2, 5
• Tizanidine has been well-studied for low back pain but may cause hepatotoxicity 2, 4

Risks and Adverse Effects

• Most muscle relaxants cause central nervous system side effects, primarily sedation and dizziness 6, 4
• The number needed to harm (NNTH) for adverse events with muscle relaxants is approximately 3, meaning for every 3 patients treated, 1 will experience adverse effects 6
• Combining muscle relaxants with opioids significantly increases the risk of respiratory depression and death (3-10 fold higher risk) 2
• Older adults are particularly susceptible to adverse effects of muscle relaxants, including increased risk of falls 2

Special Considerations for Chronic Pain

• Despite being commonly prescribed, so-called muscle relaxants (methocarbamol, carisoprodol, chlorzoxazone, metaxalone, and cyclobenzaprine) have no evidence of efficacy in chronic pain 2
• For chronic widespread pain or fibromyalgia, evidence-based guidelines support trials of analgesic antidepressants (particularly duloxetine and TCAs) and gabapentinoids (particularly pregabalin) rather than muscle relaxants 2
• If muscle spasm is suspected to be the root cause of pain, consider drugs with known effects on muscle spasm (e.g., baclofen) rather than traditional muscle relaxants 2

Alternative Approaches

• Physical therapy and exercise programs have demonstrated efficacy in reducing muscle pain and should be considered as part of the treatment approach 2
• For chronic musculoskeletal pain, antidepressants (particularly duloxetine and TCAs) may be more appropriate than muscle relaxants 2
• Cognitive interventions such as breathing exercises, relaxation techniques, and behavioral therapies can be useful adjuncts to pharmacological treatment 2

Treatment Algorithm

1. Begin with acetaminophen or NSAIDs for acute musculoskeletal pain 2
2. If inadequate relief and muscle spasm is present, add a muscle relaxant (preferably cyclobenzaprine or metaxalone) for a short duration (≤2-3 weeks) 1, 4
3. Implement non-pharmacological approaches including rest, physical therapy, and heat/cold application 2
4. For chronic pain, transition away from muscle relaxants to more appropriate long-term options such as antidepressants or gabapentinoids 2
5. Avoid combining muscle relaxants with opioids or benzodiazepines due to significantly increased risk 2