Tizanidine Dosing and Administration for Muscle Spasms
For muscle spasms, tizanidine should be initiated at 2-4 mg orally and titrated gradually in 2-4 mg increments to an optimal dose of 8 mg every 6-8 hours, not exceeding 36 mg total daily dose. 1
Initial Dosing
- Start with 4 mg as a single dose
- Effects peak at 1-2 hours and last 3-6 hours
- Initial pain relief typically occurs by the second day of treatment 2
Titration Schedule
- Increase dose gradually in 2-4 mg increments
- Adjust based on clinical response and tolerability
- Allow sufficient time between dose increases to assess effects
Maintenance Dosing
- Optimal single dose: 8 mg (shown to be effective in clinical studies)
- Frequency: Every 6-8 hours as needed
- Maximum frequency: 3 doses in 24 hours
- Maximum daily dose: 36 mg 1
- Complete pain relief typically achieved after approximately 4 days of treatment 2
Administration Considerations
- Food significantly affects tizanidine pharmacokinetics
- Consistent administration (either always with food or always without) is recommended to avoid fluctuations in drug levels
- Taking with food may reduce peak concentrations but increase overall bioavailability 1
Special Populations
- Elderly patients: Start at lower doses due to increased risk of sedative and hypotensive effects
- Hepatic/renal impairment: Avoid or use with caution; significant dose reductions may be required 3
Important Precautions
- Tizanidine is an α2-adrenergic receptor agonist (clonidine derivative)
- Common adverse effects include dose-dependent sedation, drowsiness, dizziness, ataxia, and lethargy 3
- Contraindicated with CYP1A2 inhibitors (ciprofloxacin, fluvoxamine)
- Significant drug interactions with oral contraceptives, acyclovir, amiodarone, verapamil, mexiletine, propafenone, cimetidine, and famotidine 3
Discontinuation
- For long-term use, taper slowly rather than stopping abruptly
- Abrupt discontinuation may cause withdrawal symptoms including rebound tachycardia, hypertension, and hypertonia 3
Clinical Pearls
- Lower daily dosages (often the lowest recommended dose) are typically sufficient to achieve analgesic effects 2
- Tizanidine has shown benefits for perioperative pain control, reduced midazolam requirements, decreased opioid consumption, and hemodynamic stability 3
- In patients with spasticity due to multiple sclerosis, tizanidine (8-36 mg/day) has shown similar improvement in spastic state compared to baclofen, with potentially better preservation of muscle strength 4
- Tizanidine is generally well-tolerated with adverse effects occurring in less than 6% of patients 2