What medication is recommended for a patient experiencing muscle spasms?

Recommended Medication for Muscle Spasms

For acute muscle spasms, cyclobenzaprine 5 mg three times daily for 7-14 days is the recommended first-line medication, as it is FDA-approved for this indication and has the strongest evidence for efficacy in acute painful musculoskeletal conditions. 1, 2

Treatment Algorithm

First-Line Therapy

• Cyclobenzaprine 5 mg three times daily is the optimal starting regimen for acute muscle spasms 2
• This dose provides equivalent efficacy to 10 mg three times daily but with significantly less sedation 2
• Treatment duration should be limited to 2-3 weeks maximum, as cyclobenzaprine is FDA-approved only for short-term use and effectiveness beyond this period is not established 1
• Onset of relief occurs within 3-4 doses of the 5 mg regimen 2

Alternative First-Line Option

• Tizanidine 2-4 mg with upward titration is an appropriate alternative when cyclobenzaprine is not tolerated or contraindicated 3, 4
• The American College of Physicians recognizes tizanidine as having a favorable efficacy and safety profile 4
• Requires monitoring for hepatotoxicity (generally reversible) and orthostatic hypotension 3, 4

Combination Therapy Strategy

Adding a muscle relaxant to an NSAID or acetaminophen provides consistently greater short-term pain relief than analgesic monotherapy 3, 5, 4

• This combination increases CNS adverse events (relative risk 2.44) but may reduce gastrointestinal adverse events (relative risk 0.54) 3, 4
• Consider combination therapy when pain is moderate to severe 5

Medications to Avoid

Benzodiazepines (Diazepam)

• Do not use benzodiazepines as first-line therapy due to abuse potential and lack of superior efficacy 5, 4
• While diazepam is FDA-approved as an adjunct for skeletal muscle spasm, it should be reserved only for situations where anxiety, muscle spasm, and pain coexist 5, 6
• Benzodiazepines carry particularly high risk in older adults, including increased fall risk 5, 4

Stroke Recovery Period

• Avoid diazepam and other benzodiazepines during stroke recovery due to possible deleterious effects on neurologic recovery 7

Special Population Considerations

Elderly Patients

• Avoid cyclobenzaprine in elderly patients due to anticholinergic adverse effects and increased fall risk 5
• If muscle relaxant therapy is necessary in elderly patients, baclofen 5 mg up to three times daily is the preferred agent, with maximum tolerated doses of 30-40 mg per day 5
• Tizanidine starting at 2 mg up to three times daily is an alternative for elderly patients, though requires monitoring for orthostatic hypotension and sedation 5

Patients with Renal or Hepatic Impairment

• Avoid methocarbamol and metaxalone in patients with renal or hepatic impairment 5
• Use baclofen or tizanidine with caution, starting at the lowest effective dose 5

Critical Safety Considerations

Common Adverse Effects

• All skeletal muscle relaxants increase total adverse events by 50% and double CNS adverse events compared to placebo 5, 4
• Somnolence and dry mouth are the most common adverse effects with cyclobenzaprine, occurring in a dose-related manner 2
• Sedation, dizziness, dry mouth, and increased fall risk are consistently reported across all muscle relaxants 5, 8

Important Caveats

• The term "muscle relaxant" is misleading—these drugs do not directly relax skeletal muscle but likely work through sedative properties 5, 4
• Efficacy is independent of sedation, as meaningful treatment effects are observed even in patients who do not report somnolence 2
• Never prescribe muscle relaxants for chronic pain conditions, as there is no evidence of benefit beyond 2-3 weeks 5

Discontinuation Precautions

• Abrupt discontinuation of baclofen must be avoided due to risk of withdrawal symptoms including CNS irritability; slow tapering is required after prolonged use 5

Non-Pharmacological Adjuncts

Consider non-pharmacological approaches as adjuncts to medication therapy 5:

• Rest and physical therapy
• Range of motion exercises
• Stretching and positioning

Conditions NOT Indicated for These Medications

Cyclobenzaprine has not been found effective in the treatment of spasticity associated with cerebral or spinal cord disease, or in children with cerebral palsy 1

For spasticity from upper motor neuron disorders (stroke, cerebral palsy, paraplegia), consider antispasticity agents such as tizanidine, baclofen, or dantrolene instead 7