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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

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.