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Tizanidine Pregnancy and Breastfeeding Warnings

Tizanidine is also known as: Zanaflex

Tizanidine Pregnancy Warnings

Benefit should outweigh risk

US FDA pregnancy category: C

Teratogenicity was not shown in animal studies in rats and rabbits. At doses up to 8 times the maximum recommended human dose, increased gestation duration was observed in rats. Pre and prenatal and postnatal pup loss and developmental retardation occurred in rats and rabbits and post-implantation loss was increased in rabbits at doses of 1 mg/kg or more. There are no controlled studies in pregnant women.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

See references

Tizanidine Breastfeeding Warnings

Safety has not been established

Excreted into human milk: Unknown
Excreted into animal milk: Yes

Comments: If used, monitor infant for toxicity such as sedation, hypotension, and hallucinations.

As a lipid soluble drug, it might be expected to pass into breast milk.

See references

References for pregnancy information

  1. "Product Information. Zanaflex (tizanidine)." Acorda Therapeutics (2001):

References for breastfeeding information

  1. "Product Information. Zanaflex (tizanidine)." Acorda Therapeutics (2001):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.