What are the recommended muscle relaxants with minimal side effects for elderly patients?

Muscle Relaxant Recommendations for Elderly Patients

Based on the most recent evidence, baclofen and tizanidine are the preferred muscle relaxants for elderly patients due to their relatively better safety profiles, though all muscle relaxants should be used with caution in this population. 1

General Considerations

• Muscle relaxants as a class are listed in the American Geriatrics Society 2019 Beers Criteria® as potentially inappropriate medications for older adults due to anticholinergic effects, sedation, and increased risk of falls 1
• Most muscle relaxants do not directly relax skeletal muscle and have limited evidence of efficacy for chronic pain management in elderly patients 1
• The risks of adverse effects often outweigh potential benefits in older adults 2

Recommended Options

First-line options:

• Baclofen:

  • Recommended starting dose: 5 mg up to three times daily 1
  • Better tolerated in elderly patients compared to other muscle relaxants 1
  • Maximum tolerated dose in older adults is typically 30-40 mg per day 1
  • Monitor for muscle weakness, urinary function, cognitive effects, and sedation 1

• Tizanidine (Zanaflex):

  • Recommended starting dose: 2 mg up to three times daily 1
  • Clearance is reduced by more than 50% in elderly patients with renal insufficiency 3
  • Use with caution in renally impaired patients 3
  • Monitor for orthostatic hypotension, sedation, and potential drug-drug interactions 1

Muscle Relaxants to Avoid in Elderly

• Cyclobenzaprine:

  • Structurally similar to tricyclic antidepressants with comparable adverse effect profile 2
  • Plasma concentration is increased in the elderly 4
  • Higher risk of CNS adverse events including hallucinations and confusion 4
  • Should be avoided or used at lower doses (5 mg) if absolutely necessary 4

• Carisoprodol:

  • Has been removed from the European market due to concerns about drug abuse 1
  • High risk of sedation and falls in elderly patients 1

• Orphenadrine:

  • Strong anticholinergic properties that can cause confusion, urinary retention, and cardiovascular instability 2
  • Listed in Beers Criteria as potentially inappropriate for older adults 1

• Methocarbamol:

  • Elimination is significantly impaired in patients with liver and kidney disease 2
  • Can cause drowsiness, dizziness, and cardiovascular effects 2

• Metaxalone:

  • Contraindicated in patients with significant hepatic or renal dysfunction 2
  • Multiple central nervous system adverse effects 2

Dosing Considerations

• Start with the lowest possible effective dose 1
• Use for the shortest duration necessary 1
• For baclofen, older persons rarely tolerate doses greater than 30-40 mg per day 1
• For tizanidine, start with 2 mg and titrate slowly while monitoring for side effects 1, 3

Monitoring Recommendations

• Assess for sedation, dizziness, and cognitive impairment at each follow-up visit 2
• Monitor for falls, especially during the initial treatment period 1
• Evaluate renal function before starting therapy and periodically during treatment 3
• Watch for drug-drug interactions, particularly with other CNS depressants 4

Alternative Approaches

• Consider non-pharmacological approaches first for muscle spasm management 2
• Topical analgesics may provide localized relief with fewer systemic side effects 2
• Scheduled acetaminophen (up to 3g/day) may be effective for mild to moderate musculoskeletal pain 5
• Physical therapy and exercise programs focusing on strengthening, flexibility, and balance 5

Key Pitfalls to Avoid

• Avoid prescribing muscle relaxants with other medications that have anticholinergic properties 1
• Do not combine with benzodiazepines or other CNS depressants due to additive sedative effects 4
• Be cautious with concomitant use of antihypertensive medications, as some muscle relaxants (especially tizanidine) can cause hypotension 3
• Avoid abrupt discontinuation of baclofen due to risk of withdrawal symptoms including CNS irritability 1