Tizanidine: Uses and Indications
Tizanidine is FDA-approved specifically for the management of spasticity associated with upper motor neuron syndromes such as stroke, multiple sclerosis, and spinal cord injury. 1
Primary Indications
- Tizanidine is a centrally acting alpha-2 adrenergic receptor agonist that functions as a muscle relaxant for treating spasticity (increased muscle tone) 2
- It is indicated for short-term relief of spasticity, with treatment reserved for those daily activities and times when relief of spasticity is most important 1
- Tizanidine is recommended for treating spasticity resulting in pain, poor skin hygiene, or decreased function in patients with chronic stroke 3
- It is an effective option for management of spasticity in patients with spinal cord injury 4
Clinical Applications in Specific Conditions
- Stroke rehabilitation: Tizanidine is specifically recommended for chronic stroke patients with spasticity that results in pain, poor skin hygiene, or decreased function 3
- Multiple sclerosis: Tizanidine has been shown to reduce spastic muscle tone by approximately 20% within an effective dose range of 24-36 mg daily 5
- Spinal cord injury: Clinical trials have demonstrated significant reduction in muscle tone (assessed by Ashworth score) in patients with spinal cord injury of >12 months duration 4
- Low back pain: Tizanidine has shown efficacy for acute low back pain in clinical trials, though it is not FDA-approved for this indication 3
Dosing Considerations
- Optimal dosage must be titrated over 2-4 weeks for each patient due to wide interpatient variability in effective plasma concentrations 6
- Dosages ranging from 2 to 36 mg/day have been used in clinical trials 6
- Maximum effects typically occur within 2 hours of administration 6
- The medication should be used judiciously as it has a short duration of effect 1
Advantages Compared to Other Muscle Relaxants
- Tizanidine has similar efficacy to baclofen but with a more favorable tolerability profile 6
- Subjective muscle weakness appears to be less problematic with tizanidine compared to baclofen 6
- Unlike diazepam or other benzodiazepines, tizanidine is not contraindicated during stroke recovery 3
Common Adverse Effects
- The most frequent adverse events include dry mouth (xerostomia), somnolence/drowsiness, and fatigue 6, 4
- Tizanidine can cause significant hypotension, which requires monitoring 2
- Despite these side effects, global tolerability has been assessed as good to excellent in 44-100% of patients receiving tizanidine 6
Important Cautions
- Tizanidine is specifically for treating spasticity (increased muscle tone), not hypotonia (reduced muscle tone) 2
- For patients who do not respond to oral medications like tizanidine, more invasive options such as botulinum toxin injections, intrathecal baclofen, or neurosurgical procedures may be considered 2
- When used for non-FDA approved indications such as low back pain, treatment duration in clinical trials was typically 2 weeks or less 3