Zostiva Valacyclovir Cimetidine
ModerateCimetidine slows how the kidneys clear aciclovir, the active form of valacyclovir, so aciclovir levels rise by about 25% after a 1000 mg dose. Probenecid does the same, raising levels by about 45%.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.
What to do: Ask your doctor or pharmacist. They may check you or change the plan. Do not change any dose on your own.