Tizanidine Dosing Guidelines
Tizanidine can be taken up to three times daily with a maximum daily dose of 36 mg, but should be started at a low dose of 2 mg per dose and gradually titrated upward. 1, 2
Recommended Dosing Schedule
- Starting dose: 2 mg up to three times daily 3, 2
- Dose titration: Increase gradually in 2-4 mg steps to achieve optimal effect 1
- Dosing interval: Every 6-8 hours as needed 1
- Maximum frequency: Three doses in 24 hours 1
- Maximum daily dose: 36 mg total per day 1
Important Pharmacokinetic Considerations
- Peak effect occurs at approximately 1-2 hours after administration 1, 4
- Effects typically dissipate between 3-6 hours 1
- Food has complex effects on tizanidine pharmacokinetics, which can significantly alter drug levels and potentially increase adverse events 1
- For consistency, tizanidine should be taken either always with food or always without food 1
Special Population Considerations
Elderly Patients
- Lower starting dose recommended (2 mg)
- Older persons rarely tolerate doses greater than 30-40 mg per day 3
- Monitor closely for orthostatic hypotension and sedation 2
Patients with Hepatic or Renal Impairment
- Require careful monitoring and potential dose adjustments 2
- Significant dose reductions may be necessary 2
Monitoring and Adverse Effects
- Common side effects: Drowsiness, dizziness, dry mouth, sedation 2, 4
- Important monitoring parameters: 2
- Muscle weakness
- Urinary function
- Cognitive effects
- Sedation
- Orthostatic hypotension
- Potential drug-drug interactions
Clinical Pearls
- Wide interpatient variability exists in effective plasma concentrations, necessitating individualized dose titration over 2-4 weeks 4
- Tizanidine has potential for many drug-drug interactions, particularly with CYP1A2 inhibitors 2
- If daytime drowsiness is problematic, administration can be restricted to bedtime 5
- Abrupt discontinuation should be avoided; taper slowly, especially after long-term use 2
By following these dosing guidelines, you can maximize the therapeutic benefits of tizanidine while minimizing potential adverse effects. The medication's short duration of action allows for flexible dosing throughout the day based on symptom patterns and individual response.