What muscle relaxer is safe to use in the elderly?

Muscle Relaxants in the Elderly: Safety Considerations

Muscle relaxants should generally be avoided in elderly patients due to increased risk of falls, sedation, and adverse effects, with tizanidine or baclofen being the least inappropriate options when absolutely necessary. 1

Safety Profile of Muscle Relaxants in Elderly Patients

• Muscle relaxants as a class are listed in the American Geriatrics Society Beers Criteria® as potentially inappropriate medications for older adults due to their anticholinergic effects, sedation, and increased risk of falls 1
• The effects of muscle relaxants are nonspecific and not directly related to muscle relaxation, making their use questionable when prescribed with the mistaken belief that they relieve muscle spasm 1
• Elderly patients are at higher risk for CNS adverse events such as hallucinations and confusion, as well as cardiac events that may result in falls 2

Specific Muscle Relaxants and Their Risks

High-Risk Options (Avoid)

• Cyclobenzaprine should be avoided or used with extreme caution in the elderly as:

  • It is structurally similar to tricyclic antidepressants with comparable adverse effect profiles 1
  • Plasma concentration is increased in elderly patients 2
  • It is associated with a 22% increased risk of injury in older adults (OR 1.22,95% CI 1.02-1.45) 3
  • If absolutely necessary, it should be initiated at a lower dose of 5 mg and titrated slowly upward 2

• Carisoprodol should be avoided because:

  • It has been removed from the European market due to concerns about drug abuse 1
  • It carries a 73% increased risk of injury in older adults (OR 1.73,95% CI 1.04-2.88) 3
  • It has substantial abuse potential and is classified as a controlled substance 4

• Methocarbamol should be avoided as:

  • It is associated with a 42% increased risk of injury (OR 1.42,95% CI 1.16-1.75) 3
  • It can cause adverse effects including drowsiness, dizziness, bradycardia, and hypotension 4

Lower-Risk Options (Use with Caution)

• Baclofen may be considered when a muscle relaxant is absolutely necessary because:

  • It has documented efficacy as a second-line drug for paroxysmal neuropathic pain 1
  • Starting with a low dose and gradually increasing may minimize common side effects of dizziness, somnolence, and gastrointestinal symptoms 1, 4
  • Discontinuation after prolonged use requires a slow tapering period to avoid withdrawal symptoms 1, 4

• Tizanidine may be considered with caution as:

  • It has shown efficacy for musculoskeletal conditions in clinical trials 5
  • However, it may cause significant sedative and hypotensive effects, particularly in elderly patients 4

Evidence-Based Approach to Muscle Relaxant Use in the Elderly

• A retrospective study of 322,806 older adults found that muscle relaxant use was associated with a 32% increased risk of injury requiring medical attention (OR 1.32,95% CI 1.16-1.50) 3
• For every 333 elderly patients treated with a muscle relaxant, one additional injury occurred 6
• Independent predictors of injury included a history of previous injury (OR 3.01) and older age (OR 1.06 per year) 6

Alternative Approaches for Elderly Patients

• If muscle spasm is suspected to be the root of pain, consider alternatives with known effects on muscle spasm such as low-dose benzodiazepines, though these also carry risks 1
• For neuropathic pain, consider pregabalin, which has been studied in elderly populations, though dose adjustments may be needed due to renal excretion 7
• For musculoskeletal pain, topical analgesics may provide relief with fewer systemic side effects 1

Key Recommendations for Clinical Practice

• First-line approach: Avoid muscle relaxants in elderly patients whenever possible 1
• If absolutely necessary:
  • Choose tizanidine or baclofen as potentially less harmful options 5
  • Start with the lowest possible dose and titrate slowly 2
  • Limit duration of treatment to minimize risk 3
  • Monitor closely for sedation, confusion, and fall risk 1
• Never abruptly discontinue: Always taper muscle relaxants after prolonged use to avoid withdrawal symptoms 1, 4