Can You Prescribe Myonal (Tolperisone) for Muscle Spasm?
No, you should not prescribe Myonal (tolperisone) for muscle spasm in routine clinical practice, as it is not FDA-approved in the United States and established first-line agents (baclofen or tizanidine) are recommended by major guidelines with proven efficacy and safety profiles. 1, 2
Recommended First-Line Agents Instead of Myonal
Baclofen (10-30 mg/day) is the preferred first-line treatment for true muscle spasms, particularly in chronic conditions, with documented efficacy and established safety data. 1, 2 This recommendation comes from the American College of Physicians and represents the standard of care.
Tizanidine is the alternative first-line option, especially effective for chronic stroke patients with spasticity, starting at 2 mg up to three times daily with slow titration. 1, 2 The American Heart Association specifically endorses this agent for spasticity-related conditions.
Why Tolperisone (Myonal) Is Not Recommended
While tolperisone shows promise in research settings, several critical factors limit its use:
Regulatory status: Tolperisone is still under clinical development in the United States and lacks FDA approval. 3, 4 The RESUME-1 Phase III trial (NCT04671082) is ongoing but not yet completed. 4
Limited evidence base: Although a Phase 2 study (STAR trial) showed tolperisone 200 mg three times daily had numerical superiority over placebo (p=0.0040 for pain reduction), this represents preliminary data requiring Phase 3 confirmation. 3
Availability: The drug is marketed primarily in Japan and some European countries but is not accessible through standard US prescribing channels. 5
Clinical Algorithm for Muscle Spasm Management
Step 1: Identify the type of muscle problem
- True muscle spasm (involuntary contraction from CNS injury, demyelinating disease) → Use baclofen 1, 2
- Spasticity from stroke → Use tizanidine, dantrolene, or oral baclofen 2
- Acute nonspecific back muscle spasm → Consider short-term cyclobenzaprine (2-3 weeks maximum) 6
Step 2: Always combine with non-pharmacological interventions
Step 3: Avoid problematic agents
- Never use benzodiazepines during stroke recovery (deleterious effects on recovery) 2
- Avoid carisoprodol (abuse potential) 1, 2
- Avoid all muscle relaxants in elderly patients when possible (increased falls, sedation, anticholinergic effects) 1, 2
Special Considerations for Elderly Patients
The American Geriatrics Society explicitly recommends avoiding muscle relaxants as a class in elderly patients due to increased risk of falls, sedation, and anticholinergic effects. 1, 2 If muscle relaxation is absolutely necessary in this population, baclofen is the preferred agent starting at 5 mg three times daily with gradual titration. 6
Critical Safety Warning
Never abruptly discontinue baclofen or other muscle relaxants after prolonged use—implement a slow tapering period to prevent withdrawal symptoms including CNS irritability. 1, 2 This is particularly important with baclofen, which can cause severe withdrawal reactions.
Tolperisone's Potential Advantage (If It Becomes Available)
The one notable advantage tolperisone demonstrated in research was the absence of somnolence and driving impairment compared to cyclobenzaprine. 7 In a validated driving simulator study, tolperisone 150 mg three times daily showed no significant difference from placebo in driving performance, while cyclobenzaprine 10 mg three times daily caused marked impairment (p<0.01). 7 However, this potential benefit does not justify off-label use of an unapproved medication when established alternatives exist.