What is the best muscle relaxer for the elderly?

From the Guidelines

For elderly patients, cyclobenzaprine (Flexeril) at a reduced dose of 5 mg once or twice daily is often considered the best muscle relaxer option. This medication is effective for short-term relief of muscle spasms and associated pain, typically used for 2-3 weeks 1. Baclofen (10 mg three times daily) and tizanidine (2-4 mg every 6-8 hours) are also reasonable alternatives, although there is little evidence for the efficacy of baclofen or dantrolene for the treatment of spasticity 1.

Key Considerations

• When prescribing for the elderly, it's essential to "start low and go slow" with dosing due to their increased sensitivity to side effects and altered drug metabolism.
• Non-medication approaches should be tried first, including physical therapy, gentle stretching, heat therapy, and massage.
• Muscle relaxers work by acting on the central nervous system to reduce muscle tone and spasticity, but they can cause significant drowsiness, dizziness, and cognitive impairment in older adults.
• They should be used cautiously in patients with liver or kidney impairment, and should be avoided with alcohol or other CNS depressants.
• Regular reassessment is necessary to minimize the duration of use and prevent dependence or adverse effects.

Alternative Options

• Tricyclic antidepressants are an option for pain relief in patients with chronic low back pain and no contraindications to this class of medications 1.
• Gabapentin is associated with small, short-term benefits in patients with radiculopathy, but has not been directly compared with other medications or treatments 1.

Safety Profile

• Carisoprodol is metabolized to meprobamate, a medication associated with risks for abuse and overdose.
• Dantrolene carries a black box warning for potentially fatal hepatotoxicity.
• Both tizanidine and chlorzoxazone are associated with hepatotoxicity that is generally reversible and usually not serious 1.

From the FDA Drug Label

Age Effects: No specific pharmacokinetic study was conducted to investigate age effects. Cross study comparison of pharmacokinetic data following single dose administration of 6 mg tizanidine showed that younger subjects cleared the drug four times faster than the elderly subjects Tizanidine clearance is reduced by more than 50% in elderly patients with renal insufficiency (creatinine clearance < 25 mL/min) compared to healthy elderly subjects; this would be expected to lead to a longer duration of clinical effect. Tizanidine should be used with caution in renally impaired patients

The best muscle relaxer for the elderly is not explicitly stated in the provided drug labels. However, tizanidine is a muscle relaxer that has been studied in patients with spasticity, and its effects in the elderly population are mentioned.

• Key points to consider when using tizanidine in the elderly:
  • Reduced clearance in elderly patients with renal insufficiency
  • Expected longer duration of clinical effect in elderly patients with renal insufficiency
  • Use with caution in renally impaired patients Based on the available information, tizanidine may be considered a muscle relaxer for the elderly, but it should be used with caution, especially in patients with renal insufficiency 2.

From the Research

Muscle Relaxers for the Elderly

• The use of muscle relaxers in the elderly population is a concern due to the potential for adverse effects, such as increased risk of injury and delirium 3, 4, 5.
• A study comparing the safety of baclofen and tizanidine in older adults found that baclofen was associated with a higher risk of injury and delirium 4.
• Another study found that the use of skeletal muscle relaxants, including carisoprodol, methocarbamol, and cyclobenzaprine, was associated with an increased risk of injury in older adults 5.
• A randomized, placebo-controlled trial found that adding baclofen, metaxalone, or tizanidine to ibuprofen did not improve functional outcomes or pain in patients with acute low back pain compared to placebo plus ibuprofen 6.

Considerations for Muscle Relaxer Use in the Elderly

• The American Geriatrics Society recommends avoiding the use of skeletal muscle relaxants in older adults due to the risk of adverse effects 3, 5.
• However, some studies suggest that the use of muscle relaxants in selected patients 65 years and older could be considered if the expected benefits outweigh the small increased risk of injury 3.
• It is essential to carefully evaluate the risks and benefits of muscle relaxant use in older adults and to consider alternative treatments, such as physical therapy and non-pharmacological interventions, whenever possible.
• Baclofen, in particular, requires careful consideration due to its potential for toxicity in patients with decreased kidney function 7.

Comparison of Muscle Relaxers

• Tizanidine may be a safer alternative to baclofen for older adults with musculoskeletal pain, as it was associated with a lower risk of injury and delirium in one study 4.
• Metaxalone and cyclobenzaprine may also be options, but their safety and efficacy in older adults require further study 6.
• Carisoprodol and methocarbamol were associated with an increased risk of injury in older adults in one study, and their use should be approached with caution 5.