Tizanidine Side Effects
Medically reviewed by Drugs.com. Last updated on Aug 15, 2023.
Summary
Commonly reported side effects of tizanidine include: bradycardia, dizziness, drowsiness, hypotension, asthenia, fatigue, and xerostomia. Other side effects include: constipation, and increased liver enzymes. Continue reading for a comprehensive list of adverse effects.
Applies to tizanidine: oral capsules and tablets.
Side effects include:
Dry mouth, somnolence, asthenia (weakness, fatigue, and/or tiredness), dizziness.
For Healthcare Professionals
Applies to tizanidine: oral capsule, oral tablet.
General
The most frequently reported adverse reactions include dry mouth, somnolence/sedation, asthenia, and dizziness.[Ref]
Nervous system
Very common (10% or more): Somnolence (up to 48%), dizziness (up to 16%)
Common (1% to 10%): Speech disorder, dyskinesia
Frequency not reported: Headache, ataxia, dysarthria
Postmarketing reports: Convulsion, paresthesia, tremor[Ref]
Gastrointestinal
Very common (10% or more): Dry mouth (up to 49%)
Common (1% to 10%): Vomiting, constipation
Rare (0.01% to 0.1%): Nausea, gastrointestinal disorder
Frequency not reported: Abdominal pain, loss of appetite[Ref]
Hepatic
Common (1% to 10%): Liver test abnormality
Very rare (less than 0.01%): Hepatic failure
Frequency not reported: Hepatotoxicity
Postmarketing reports: Hepatitis[Ref]
Cardiovascular
Common (1% to 10%): Bradycardia, hypotension, tachycardia
Postmarketing reports: Syncope, ventricular tachycardia, QT prolongation[Ref]
Ocular
Common (1% to 10%): Amblyopia
Frequency not reported: Accommodation disorder[Ref]
Dermatologic
Frequency not reported: Pruritus
Postmarketing reports: Stevens Johnson Syndrome, exfoliative dermatitis, rash[Ref]
Other
Common (1% to 10%): Fatigue
Frequency not reported: Drug withdrawal reactions including rebound hypertension, tachycardia, and hypertonia[Ref]
Genitourinary
Common (1% to 10%): Urinary tract infection, urinary frequency[Ref]
Respiratory
Common (1% to 10%): Pharyngitis, rhinitis[Ref]
Hypersensitivity
Frequency not reported: Anaphylaxis, hypersensitivity reactions
Postmarketing reports: Anaphylactic Reaction[Ref]
Immunologic
Common (1% to 10%): Infection, flu syndrome[Ref]
Musculoskeletal
Rare (0.01% to 0.1%): Muscular weakness
Postmarketing reports: Arthralgia[Ref]
Psychiatric
Common (1% to 10%): Nervousness
Rare (0.01% to 0.1%): Hallucinations, insomnia, sleep disorders
Frequency not reported: Confusional state
Postmarketing reports: Depression[Ref]
Frequently asked questions
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References
1. Product Information. Zanaflex (tizanidine). Acorda Therapeutics. 2001.
2. Cerner Multum, Inc. UK Summary of Product Characteristics.
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.