Valacyclovir is an antiviral drug active against α-herpes viruses.

VALTREX is a deoxynucleoside analogue DNA polymerase inhibitor indicated for: Adult Patients: Cold Sores (Herpes Labialis); Genital Herpes: Treatment in immunocompetent patients (initial or recurrent episode), Suppression in immunocompetent or HIV-1−infected patients, Reduction of transmission; Herpes Zoster. Pediatric Patients: Cold Sores (Herpes Labialis); Chickenpox.

Cold Sores (Herpes Labialis): The recommended dosage of VALTREX for treatment of cold sores is 2 grams twice daily for 1 day taken 12 hours apart. Therapy should be initiated at the earliest symptom of a cold sore (e.g., tingling, itching, or burning). Genital Herpes: Initial Episode: The recommended dosage of VALTREX for treatment of initial genital herpes is 1 gram twice daily for 10 days. Therapy was most effective when administered within 48 hours of the onset of signs and symptoms. Recurrent Episodes: The recommended dosage of VALTREX for treatment of recurrent genital herpes is 500 mg twice daily for 3 days. Initiate treatment at the first sign or symptom of an episode. Suppressive Therapy: The recommended dosage of VALTREX for chronic suppressive therapy of recurrent genital herpes is 1 gram once daily in patients with normal immune function. (See Full Prescribing Information.)

The most common adverse reactions reported in at least one indication by greater than 10% of adult subjects treated with VALTREX and more commonly than in subjects treated with placebo are headache, nausea, and abdominal pain. The only adverse reaction occurring in greater than 10% of pediatric subjects aged less than 18 years was headache.

VALTREX is contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction (e.g., anaphylaxis) to valacyclovir, acyclovir, or any component of the formulation.

Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS): Has occurred in patients with advanced HIV-1 disease and in allogenic bone marrow transplant and renal transplant patients receiving 8 grams per day of VALTREX in clinical trials. Discontinue treatment if clinical symptoms and laboratory findings consistent with TTP/HUS occur. Acute renal failure: May occur in elderly patients (with or without reduced renal function), patients with underlying renal disease who receive higher-than-recommended doses of VALTREX for their level of renal function, patients who receive concomitant nephrotoxic drugs, or inadequately hydrated patients. Use with caution in elderly patients and reduce dosage in patients with renal impairment. (See Full Prescribing Information.)