Is it safe to prescribe Flexeril (cyclobenzaprine) to a 46-year-old patient with multiple sclerosis (MS)?

Safety of Cyclobenzaprine in Multiple Sclerosis Patients

Cyclobenzaprine should be used with caution in patients with multiple sclerosis due to its CNS depressant effects and potential for worsening neurological symptoms. While not absolutely contraindicated, safer alternatives should be considered first.

Concerns with Cyclobenzaprine in MS Patients

• Cyclobenzaprine has atropine-like actions that may exacerbate neurological symptoms in MS patients 1
• The medication is structurally related to tricyclic antidepressants and can cause CNS depression, which may worsen cognitive function in patients with neurological conditions 1
• In elderly patients (and by extension, those with neurological conditions), cyclobenzaprine is associated with increased risk of CNS adverse events including hallucinations and confusion 1
• Muscle relaxants like cyclobenzaprine have anticholinergic properties that can worsen cognitive function in vulnerable populations 2

Specific Risks for MS Patients

• Cyclobenzaprine may enhance the effects of other CNS depressants, which is particularly concerning for MS patients who often take multiple medications 1
• The risk of serotonin syndrome is increased when cyclobenzaprine is combined with other serotonergic drugs that MS patients might be taking (SSRIs, SNRIs, TCAs) 1
• MS patients often have complex medication regimens, increasing the potential for drug-drug interactions with cyclobenzaprine 3
• Cyclobenzaprine has not been specifically studied for spasticity associated with cerebral or spinal cord disease 1

Safer Alternatives for MS Patients

• Baclofen is considered a safer and more effective option for treating spasticity specifically associated with multiple sclerosis 4
• Tizanidine has fair evidence for efficacy in spasticity primarily from multiple sclerosis with a different side effect profile that may be better tolerated 5
• Modafinil is suggested for treatment of hypersomnia secondary to multiple sclerosis, if fatigue is the primary concern 2

Recommendations for Use (If Necessary)

• If cyclobenzaprine must be used, start with a lower dose (5 mg) and titrate slowly upward 1
• Limit treatment duration to short periods (up to two or three weeks) as indicated in the FDA labeling 1
• Monitor closely for adverse effects, particularly excessive sedation, confusion, and worsening of MS symptoms 1
• Avoid combining with other CNS depressants or anticholinergic medications 1
• Be aware that cyclobenzaprine is only indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions, not for spasticity associated with neurological conditions 1

Conclusion

While cyclobenzaprine is effective for acute musculoskeletal spasm, its use in MS patients carries additional risks. Baclofen or tizanidine would be more appropriate first-line choices for treating spasticity in MS patients 4, 5. If cyclobenzaprine is used, it should be at the lowest effective dose for the shortest duration possible with careful monitoring for adverse effects 1.