Tizanidine Dosing Protocol for Muscle Spasms
For muscle spasms, tizanidine should be initiated at 2-4 mg per dose and gradually titrated up (in 2-4 mg increments) to a maximum of 36 mg daily, divided into three doses given at 6-8 hour intervals. 1
Initial Dosing
- Start with 4 mg as a single oral dose
- Effects peak at 1-2 hours and last 3-6 hours
- Lower starting doses (2 mg) recommended for:
- Elderly patients
- Patients with hepatic or renal impairment
- Patients taking CYP1A2 inhibitors (contraindicated) 2
Titration Schedule
- Increase by 2-4 mg increments every few days
- Target: Satisfactory reduction of muscle tone at a tolerated dose
- Dose can be repeated every 6-8 hours as needed
- Maximum frequency: 3 doses in 24 hours
- Maximum daily dose: 36 mg (though daily doses >24 mg have limited evidence) 1
Administration Considerations
- Food significantly affects tizanidine pharmacokinetics
- Maintain consistent administration pattern (either always with food or always without food) to avoid fluctuations in drug levels 1
- Maximum effects occur within 2 hours of administration 3
- Wide interpatient variability in effective plasma concentrations means optimal dosage must be individualized through careful titration over 2-4 weeks 3
Monitoring and Adverse Effects
- Most common side effects: dry mouth, sedation/drowsiness 3
- Monitor for:
Special Populations
- Elderly patients: Start at lower doses (2 mg up to three times daily) 2
- Hepatic/renal impairment: Significant dose reductions required 2
- Pediatric patients with spastic quadriplegia: 0.1-0.2 mg/kg/day divided into 2-3 doses has been used for sleep disturbances 4
Treatment Duration
- For acute muscle spasms: Clinical effect is prompt, with initial relief typically observed by the 2nd day of treatment and complete relief after approximately 4 days 5
- For chronic spasticity: Maximum effects on spasticity typically occur within 1 week of starting treatment 6
- Benefits may be maintained for at least 1 week after discontinuation 6
Discontinuation
- Taper slowly when stopping, especially after long-term use, to avoid withdrawal symptoms 2
Tizanidine has demonstrated efficacy comparable to other muscle relaxants like baclofen and diazepam, but with a more favorable tolerability profile and less subjective muscle weakness 3, 7. The drug's α2-adrenergic agonist properties provide both muscle relaxation and potential sleep benefits for patients with spasticity-related sleep disturbances 4.