Cyclopam Dosing for Acute Muscle Spasm
The recommended oral dose of cyclobenzaprine (Cyclopam) is 5 mg three times daily, which can be increased to 10 mg three times daily based on response, with treatment duration limited to 2-3 weeks. 1
Standard Dosing Regimen
- Start with 5 mg orally three times daily for most patients with acute skeletal muscle spasm 1
- The 5 mg three times daily regimen is as effective as 10 mg three times daily but causes significantly less sedation 2
- If inadequate response after initial dosing, increase to 10 mg three times daily 1
- Onset of relief typically occurs within 3-4 doses of the 5 mg regimen 2
- Duration of treatment should not exceed 2-3 weeks 1
Special Population Adjustments
- Elderly or hepatically impaired patients require less frequent dosing and should start at lower doses 1
- For these populations, consider initiating at 5 mg once or twice daily rather than three times daily 1
Clinical Efficacy Evidence
The 5 mg three times daily dose demonstrates:
- Significantly higher efficacy scores compared to placebo on all primary measures (patient-rated global impression of change, medication helpfulness, and relief from pain) 2
- Equivalent effectiveness to 10 mg three times daily for acute low back and neck pain 2
- Lower incidence of somnolence (the most common adverse effect) compared to the 10 mg dose 2
- Efficacy independent of sedation, as meaningful treatment effects were observed even in patients who did not report somnolence 2
Important Prescribing Considerations
The 2.5 mg three times daily dose is not recommended as it was not significantly more effective than placebo and led to higher discontinuation rates due to ineffectiveness 2
Common adverse effects are dose-related and include:
- Somnolence (most common, affecting >30% of patients at standard doses) 3, 4
- Dry mouth (anticholinergic effect) 2, 3
- These effects occur centrally via off-target antagonism of histamine H1 receptors 4
Critical safety points:
- Cyclobenzaprine has a 4-6 hour duration of action, making three-times-daily dosing necessary to avoid painful untreated intervals 2
- The medication works centrally by inhibiting tonic somatic motor function through modulation of noradrenergic and serotonergic systems 3, 4
- Overdoses are less problematic than with traditional tricyclic antidepressants despite structural similarity 3