What is Valtrex used for?
Does Valtrex help with canker sores? Valacyclovir has not been studied in the treatment of canker sores. Despite many studies trying to identify a causal microorganism, canker sores (aphthous stomatitis) does not appear to be infectious or contagious.
The only contraindication is a hypersensitivity to valacyclovir or any component in the formulation.
Valacyclovir is not metabolized by CYP isoenzymes. No clinically significant drug interactions are known.
Pregnancy Category B. It is generally safe to take valacyclovir during pregnancy.
Valacyclovir is not thought to increase the risk for birth defects. The recent study found no increase in birth defects in over 200 infants exposed to valacyclovir during the first trimester of pregnancy3.
Valtrex during breastfeeding
Valacyclovir is excreted in breast milk. However, the amount of acyclovir (the active metabolite) in breast milk after taking valacyclovir is very low1. And the dose ingested by the child is less than 2% of therapeutic dosing for neonates. Also, the American Academy of Pediatrics considers acyclovir to be safe during breastfeeding2.
Last updated: February, 2015
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