What is the safest first‑line muscle relaxant for an older adult (≥65 years) with muscle spasm?

Best Muscle Relaxant for Elderly Patients

Baclofen is the safest first-line muscle relaxant for older adults (≥65 years) with muscle spasm, starting at 5 mg three times daily and titrating slowly to a maximum of 30-40 mg per day. 1, 2

Why Baclofen is Preferred

• The American Geriatrics Society specifically recommends baclofen as the preferred agent for elderly patients requiring muscle relaxant therapy, with documented efficacy as a GABA-B agonist for muscle spasm and spasticity, particularly in CNS injury and neuromuscular disorders. 1, 2

• Baclofen requires gradual dose titration starting at 5 mg three times daily, increasing weekly by small increments to minimize common side effects of dizziness, somnolence, and gastrointestinal symptoms. 1

• Older adults rarely tolerate doses greater than 30-40 mg per day, so this should be considered the maximum target dose. 1

Critical Safety Warning for Baclofen

• Baclofen must never be discontinued abruptly - it requires slow tapering after prolonged use to avoid withdrawal symptoms including delirium, seizures, and CNS irritability. 1, 3

Alternative Option: Tizanidine

• Tizanidine is the second-line alternative, starting at 2 mg up to three times daily, but requires careful monitoring for orthostatic hypotension, sedation, and drug-drug interactions, especially in renally impaired patients. 1, 2

• However, recent comparative evidence shows baclofen carries higher risks than tizanidine: baclofen was associated with 68% increased risk of falls (subdistribution hazard ratio 1.68,95% CI 1.20-2.36) and over 3-fold increased risk of delirium (HR 3.33,95% CI 2.11-5.26) compared to tizanidine in older adults. 4, 5

• Despite guideline recommendations favoring baclofen, the most recent high-quality comparative studies (2023-2024) suggest tizanidine may actually be safer, creating a clinical dilemma between guideline authority and emerging evidence. 4, 5

Muscle Relaxants to Absolutely Avoid in Elderly

• Cyclobenzaprine should be avoided - it is structurally identical to tricyclic antidepressants with comparable adverse effects including CNS impairment, delirium, slowed comprehension, and falling, and is associated with 22% increased injury risk. 1, 2, 6

• Carisoprodol must be completely avoided - it has substantial abuse and addiction potential, high risk of sedation and falls, and 73% increased injury risk, and has been removed from the European market. 1, 2, 6

• Methocarbamol should be avoided - elimination is significantly impaired in patients with liver and kidney disease (common in elderly), causes drowsiness, dizziness, bradycardia and hypotension, and is associated with 42% increased injury risk. 1, 6

• Metaxalone is contraindicated in patients with significant hepatic or renal dysfunction and has multiple CNS adverse effects. 1, 2

• Orphenadrine should be avoided due to strong anticholinergic properties listed in the Beers Criteria as potentially inappropriate for older adults. 1, 2

Important Context: When NOT to Use Muscle Relaxants

• Most muscle relaxants do not directly relax skeletal muscle and have no evidence of efficacy in chronic pain - they should only be used when true muscle spasm or spasticity is suspected. 1

• All muscle relaxants as a class are listed in the American Geriatrics Society Beers Criteria as potentially inappropriate medications for older adults due to anticholinergic effects, sedation, and increased risk of falls. 1

• Muscle relaxants should be avoided entirely in frail patients with mobility deficits, weight loss, weakness, or cognitive deficits. 1

Non-Pharmacological Alternatives to Consider First

• The American College of Physicians recommends considering non-pharmacological approaches for muscle spasm management first, including rest and physical therapy. 1, 3

• For elderly patients with musculoskeletal pain, topical analgesics may provide relief with fewer systemic side effects. 1

• Scheduled acetaminophen may be effective for mild to moderate musculoskeletal pain in elderly patients. 1

• If the condition is primarily neuropathic pain rather than true spasticity, gabapentinoids (pregabalin, gabapentin) or duloxetine have stronger evidence for neuropathic pain in elderly patients. 1

Key Management Principles

• Start with the lowest possible effective dose and use muscle relaxants for the shortest duration necessary. 1, 2

• Avoid prescribing muscle relaxants with other medications that have anticholinergic properties. 1

• Never prescribe muscle relaxants for chronic pain conditions - there is no evidence of benefit beyond 2-3 weeks. 3

• All muscle relaxants are associated with 50% higher total adverse events and double the CNS adverse events compared to placebo, with common effects including somnolence, dizziness, dry mouth, and increased fall risk. 3