Valacyclovir (valacyclovir HCl)

Dosage of valacyclovir hydrochloride is expressed in terms of valacyclovir.

Valacyclovir dosage modification according to renal function may be necessary in geriatric patients, depending on the underlying renal status of the patient. (See Dosage and Administration: Dosage in Renal and Hepatic Impairment.)

The manufacturer states that valacyclovir should be used with caution in patients receiving potentially nephrotoxic agents because this may increase the risk of renal dysfunction and/or reversible CNS manifestations. In patients with impaired renal function, doses and/or frequency of administration of valacyclovir must be modified in response to the degree of impairment.

For the treatment of first episodes of genital herpes in immunocompetent adults with impaired renal function, the manufacturer states that patients with creatinine clearances of 30 mL/minute per 1.73 m2 or greater may receive the usual oral valacyclovir dosage of 1 g every 12 hours; however, those with creatinine clearances of 10-29 or less than 10 mL/minute per 1.73 m2 should receive 1 g or 500 mg, respectively, once every 24 hours. For the episodic treatment of recurrent genital herpes in immunocompetent adults with impaired renal function, patients with creatinine clearances of 30 mL/minute per 1.73 m2 may receive the usual dosage of 500 mg every 12 hours, but those with clearances of 29 mL/minute per 1.73 m2 or less should receive 500 mg once every 24 hours.

For chronic suppression of recurrent episodes of genital herpes in immunocompetent adults with renal impairment, those with creatinine clearances of 30 mL/minute per 1.73 m2 or greater may receive the usually recommended dosage of oral valacyclovir. Patients with creatinine clearances less than 30 mL/minute per 1.73 m2 should receive 500 mg once every 24 hours; alternatively, those with a history of 9 or fewer recurrences per year may receive 500 mg once every 48 hours.

For chronic suppression of recurrent episodes of genital herpes in HIV-infected adults with renal impairment, those with creatinine clearances of 30 mL/minute per 1.73 m2 or greater may receive the usually recommended dosage of oral valacyclovir and those with creatinine clearances less than 30 mL/minute per 1.73 m2 should receive 500 mg once every 24 hours.

For the treatment of herpes labialis (cold sores) in patients with renal impairment, patients with creatinine clearances of 50 mL/minute or greater per 1.73 m2 may receive the usual oral valacyclovir dosage of 2 g every 12 hours for 1 day. Those with creatinine clearances of 30-49 mL/minute per 1.73 m2 should receive 1 g every 12 hours for 1 day, those with creatinine clearances of 10-29mL/minute per 1.73 m2 should receive 500 mg every 12 hours for 1 day, and those with creatinine clearances less than 10 mL/minute per 1.73 m2 should receive a single 500-mg dose.

For the treatment of acute, localized herpes zoster in adults, the manufacturer states that patients with creatinine clearances of 50 mL/minute or greater per 1.73 m2 may receive the usual oral valacyclovir dosage of 1 g every 8 hours. Those with creatinine clearances of 30-49 mL/minute per 1.73 m2 should receive 1 g every 12 hours, and those with creatinine clearances of 10-29 or less than 10 mL/minute per 1.73 m2 should receive 1 g or 500 mg, respectively, once every 24 hours.

Because acyclovir is removed by hemodialysis, the manufacturer states that patients undergoing hemodialysis may require a supplemental dose of valacyclovir after each dialysis period. However, if usual dosing coincides with a valacyclovir dose being administered soon after hemodialysis and subsequent dialysis takes place toward the end of the dosing interval, a supplemental dose would not be necessary.

Information regarding use of valacyclovir in patients undergoing peritoneal dialysis is not available. Based on experience with acyclovir, the manufacturer states that supplemental doses of valacyclovir do not appear to be necessary following peritoneal dialysis, either continuous ambulatory peritoneal dialysis (CAPD) or continuous arteriovenous hemofiltration/dialysis (CAVHD).

The rate but not the extent of conversion of valacyclovir to acyclovir may be reduced in patients with moderate (biopsy-proven cirrhosis) or severe (with and without ascites and biopsy-proven cirrhosis) hepatic impairment. Therefore, the manufacturer states that dosage modification is not necessary for patients with cirrhosis.

Valacyclovir hydrochloride is administered orally without regard to meals. Food does not affect systemic bioavailability of the drug.

Patients should maintain adequate hydration during valacyclovir treatment.

No dosing information is available for this tab.

No dosing information is available for this tab.

There is no enhanced messaging for this drug.

There are no contraindication interactions for this drug.

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

Known hypersensitivity or intolerance to valacyclovir, acyclovir, or any component of the formulation.

There are no contraindication contraindications for this drug.

There are no severe contraindications for this drug.

There are no moderate contraindications for this drug.

Headache, nausea, vomiting.

There are no severe adverse reactions for this drug.

There are no less severe adverse reactions for this drug.

No enhanced messaging available.

Safety and efficacy not established in prepubertal children.

Category B.

Acyclovir distributed into human milk following oral administration of valacyclovir. Use valacyclovir with caution.

Increased risk of adverse renal or CNS effects. CNS effects reported more frequently in geriatric adults than in younger adults include agitation, hallucinations, confusion, delirium, and encephalopathy. In herpes zoster, longer duration of pain after healing (post-herpetic neuralgia) than in younger adults. Consider age-related decreases in renal function when selecting dosage and adjust dosage if necessary. (See Renal Impairment under Dosage and Administration.)