What is the recommended management for an adult patient presenting with an acute muscle spasm?

Treatment of Acute Muscle Spasm in Adults

For acute muscle spasm in adults, initiate baclofen 10-30 mg/day combined with mandatory stretching exercises, massage therapy, and ice application as first-line treatment. 1

First-Line Pharmacological Treatment

Baclofen is the evidence-based first-line agent for severe muscle spasms, functioning as a GABAB agonist that is most effective for spasticity-related muscle spasms rather than simple musculoskeletal pain. 1, 2

• Start baclofen at 10-30 mg/day for acute presentations 1, 2
• For chronic spasticity conditions, initiate at lower doses (5-10 mg/day) and titrate slowly upward to minimize side effects, with typical maintenance dosing of 30-80 mg/day divided into 3-4 doses 1, 2, 3
• Allow 4-8 weeks at maximum tolerated dose before declaring treatment failure 3

Alternative First-Line Agent: Tizanidine

Tizanidine represents an equally effective alternative, particularly when cardiovascular contraindications to baclofen exist or in stroke patients with spasticity. 1, 2

• Tizanidine may be preferred when vagolysis from baclofen is contraindicated (e.g., cardiovascular disease) 2
• The American Heart Association specifically recommends tizanidine for spasticity resulting in pain, poor skin hygiene, or decreased function, particularly in chronic stroke patients 1

Mandatory Non-Pharmacological Interventions

All pharmacological treatment must be accompanied by non-pharmacological interventions - this is not optional. 1, 2

• Stretching exercises of affected muscles are essential 2
• Massage therapy to the affected area must be implemented 2
• Ice application for acute spasms is a necessary component 2
• Begin with positioning, range of motion exercises, and splinting before escalating to pharmacological therapy 1, 2

Critical Medications to Avoid

Benzodiazepines (Including Diazepam)

Never prescribe benzodiazepines for muscle spasms, particularly in stroke recovery patients. 4, 1

• The American Heart Association explicitly recommends against diazepam or other benzodiazepines during stroke recovery due to deleterious effects on neurological recovery 1, 3
• The FDA added a black box warning in 2016 against co-prescribing opioids and benzodiazepines due to 3- to 10-fold increased risk of death 4
• The American Geriatrics Society recommends avoiding muscle relaxants, particularly benzodiazepines, in elderly patients due to increased risk of falls, sedation, and anticholinergic effects 1

Carisoprodol

Avoid carisoprodol entirely due to significant drug abuse potential. 2

Cyclobenzaprine as Alternative Option

For acute, painful musculoskeletal conditions specifically, cyclobenzaprine may be considered as an adjunct to rest and physical therapy. 5

• FDA-approved only for short-term use (2-3 weeks maximum) because adequate evidence of effectiveness for more prolonged use is not available 5
• Cyclobenzaprine is NOT effective for spasticity associated with cerebral or spinal cord disease 5
• Historical data shows cyclobenzaprine was superior to placebo with rapid onset of action, though this represents older evidence from 1988 6

Treatment Algorithm

1. Initiate non-pharmacological interventions immediately: positioning, stretching, massage, ice application 1, 2

2. If inadequate response, add baclofen:

   • Start 10-30 mg/day for acute spasms 1, 2
   • Or start 5-10 mg/day for chronic conditions, titrating to 30-80 mg/day divided into 3-4 doses 1, 2

3. Consider tizanidine as alternative if baclofen contraindicated or in stroke patients 1, 2

4. For focal spasticity, botulinum toxin injections are superior to oral agents 3

5. For refractory severe spasticity, consider intrathecal baclofen 3

Critical Safety Warnings

Discontinuation Protocol

Never abruptly discontinue baclofen after prolonged use - this can cause life-threatening withdrawal syndrome including seizures, hallucinations, delirium, fever, tachycardia, and potentially death. 1, 2, 3

• Implement a slow tapering schedule over weeks to prevent withdrawal symptoms 1, 2
• Abrupt cessation of intrathecal baclofen can lead to catastrophic withdrawal syndrome evolving over 1-3 days 3

Baclofen Side Effects

Baclofen can cause dizziness, gastrointestinal symptoms, and may worsen obstructive sleep apnea by promoting upper airway collapse during sleep. 1, 3

Renal Impairment Considerations

Patients with moderate or greater renal impairment must start with the lowest dose of baclofen (5 mg/day) due to renal clearance, with mandatory dose reduction. 3

Important Clinical Pitfall

Baclofen has minimal data supporting efficacy for non-spasticity-related pain conditions. 1, 2

• For neuropathic pain without spasticity, gabapentinoids (pregabalin, gabapentin) are superior first-line choices 1, 2, 3
• Baclofen is primarily effective for spasticity-related muscle spasms, not simple musculoskeletal pain 1, 2

Special Populations

Elderly Patients

• Use lower starting doses (5 mg/day) and slower titration schedules 3
• Elderly patients are more susceptible to adverse effects due to altered pharmacokinetics 3
• Monitor supine and standing blood pressure, renal function, and serum potassium when initiating therapy 3

Co-prescribing Caution

Avoid co-prescribing muscle relaxants with opioids at discharge - recent meta-analyses show combination therapy does not outperform NSAID monotherapy for acute low back pain and increases risk of patient harm. 4