Highlights Of Prescribing Information
These highlights do not include all the information needed to use ZANAFLEX® safely and effectively.
See full prescribing information for ZANAFLEX.
- ZANAFLEX® (tizanidine hydrochloride) capsules, for oral use
- ZANAFLEX® (tizanidine hydrochloride) tablets, for oral use
Dosage and Administration
- Recommended starting dose: 2 mg; dose can be repeated at 6 to 8 hour intervals, up to a maximum of 3 doses in 24 hours
- Dosage can be increased by 2 mg to 4 mg per dose, with 1 to 4 days between increases; total daily dose should not exceed 36 mg
- Tizanidine pharmacokinetics differs between tablets and capsules, and when taken with or without food. These differences could result in a change in tolerability and control of symptoms
- To discontinue Zanaflex, decrease dose slowly to minimize the risk of withdrawal and rebound hypertension, tachycardia, and hypertonia
Warnings and Precautions
- Hypotension: monitor for signs and symptoms of hypotension, in particular in patients receiving concurrent antihypertensives; Zanaflex should not be used with other α2-adrenergic agonists
- Risk of liver injury: monitor ALTs; discontinue Zanaflex if liver injury occurs
- Sedation: Zanaflex may interfere with everyday activities; sedative effects of Zanaflex, alcohol, and other CNS depressants are additive
- Hallucinations: consider discontinuation of Zanaflex
- Less potent inhibitors of CYP1A2: may cause hypotension, bradycardia, or excessive drowsiness, use caution if Zanaflex is used with less potent inhibitors of CYP1A2, e.g., zileuton, other fluoroquinolones, antiarrhythmics, cimetidine, famotidine, oral contraceptives, acyclovir, and ticlopidine
- Renal impairment (creatinine clearance < 25 mL/min): use Zanaflex with caution, and monitor closely for dry mouth, somnolence, asthenia and dizziness as indicators of potential overdose
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Adverse Reactions
- The most common adverse reactions (greater than 2% of 264 patients taking tizanidine and greater than in placebo-treated patients in three multiple dose, placebo-controlled studies) were dry mouth, somnolence, asthenia, dizziness, urinary tract infection, constipation, liver function tests abnormal, vomiting, speech disorder, amblyopia, urinary frequency, flu syndrome, SGPT/ALT increased, dyskinesia, nervousness, pharyngitis, and rhinitis
To report SUSPECTED ADVERSE REACTIONS, contact Legacy Pharma at 1-800-727-7151 or FDA at
1-800-FDA-1088 or www.fda.gov/medwatch. -
Use In Specific Populations
- Pregnancy: Based on animal data, may cause fetal harm
- Geriatric use: Zanaflex should be used with caution in elderly patients because clearance is decreased four-fold (8.5)