What Tizanidine Is Used For
Tizanidine is a centrally acting muscle relaxant FDA-approved for managing spasticity (increased muscle tone) associated with upper motor neuron disorders such as stroke, multiple sclerosis, and spinal cord injury. 1
Primary FDA-Approved Indication
- Tizanidine is specifically indicated for the management of spasticity, which is characterized by increased muscle tone from upper motor neuron syndromes 1
- The FDA label emphasizes that tizanidine is a short-acting drug, and treatment should be reserved for daily activities and times when relief of spasticity is most important 1
- The American Heart Association recommends tizanidine for treating spasticity that results in pain, poor skin hygiene, or decreased function in patients with chronic stroke 2
Mechanism of Action
- Tizanidine functions as a centrally acting alpha-2 adrenergic receptor agonist that reduces muscle tone without significantly affecting muscle strength 2, 3
- Clinical trials demonstrate that tizanidine reduces mean muscle tone scores by 21-37% compared to 4-9% with placebo 3
- Maximum effects occur within 2 hours of administration, with benefits maintained for at least 1 week after discontinuation 4
Specific Conditions Where Tizanidine Is Effective
Spinal Cord Injury
- Tizanidine significantly reduces muscle tone (measured by Ashworth score) in patients with spinal cord injury of >12 months duration 5
- Video motion analysis confirms objective improvement in spasticity without significant alterations in muscle strength 5
Multiple Sclerosis
- In MS patients, tizanidine achieves a 20% mean reduction in muscle tone at effective doses of 24-36 mg daily 4
- Approximately 75% of MS patients report subjective improvement without increased muscle weakness 4
Acquired Brain Injury
- Clinical studies support tizanidine use for spasticity management in patients with acquired brain injury 6
Off-Label Uses (Not FDA-Approved)
Acute Low Back Pain
- The American College of Physicians recognizes tizanidine as an option for short-term relief of acute low back pain, including sciatica 2
- Clinical trials showing efficacy for low back pain typically used treatment durations of 2 weeks or less 2
- This is an off-label use and not FDA-approved 2
Pain Syndromes
- Evidence suggests clinical effectiveness in myofascial pain, lower back pain, and trigeminal neuralgia 6
- These applications remain off-label and should be considered only for short-term use 2
Critical Safety Considerations
- Tizanidine can cause significant hypotension requiring monitoring 2, 7
- The most common adverse effects are dry mouth and somnolence/drowsiness 3
- Unlike benzodiazepines such as diazepam, tizanidine is not contraindicated during stroke recovery 2
- Subjective muscle weakness is reported less often with tizanidine compared to baclofen or diazepam 3