Valaciclovir drug interactions

Drug interactions
The pharmacokinetics of digoxin was not affected by coadministration of Valaciclovir 1 gram 3 times daily, and the pharmacokinetics of acyclovir after a single dose of Valaciclovir (1 gram) was unchanged by coadministration of digoxin (2 doses of 0.75 mg), single doses of antacids (Al3+ or Mg++), or multiple doses of thiazide diuretics. Acyclovir Cmax and AUC following a single dose of Valaciclovir (1 gram) increased by 8% and 32%, respectively, after a single dose of cimetidine (800 mg), or by 22% and 49%, respectively, after probenecid (1 gram), or by 30% and 78%, respectively, after a combination of cimetidine and probenecid, primarily due to a reduction in renal clearance of acyclovir. These effects are not considered to be of clinical significance insubjects with normal renal function. Therefore, no dosage adjustment is recommended when Valaciclovir is coadministered with digoxin, antacids, thiazide diuretics, cimetidine, or probenecid in subjects with normal renal function.