Valacyclovir is the hydrochloride salt of L-valyl ester of the antiviral drug acyclovir. Valacyclovir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Valacyclovir lessens the symptoms of infections and shortens the length of time of sickness. Valacyclovir is used in the treatment and suppression of genital herpes, shingles and cold sores.

Valacyclovir is indicated for the treatment of Herpes zoster (shingles). It is indicated for the treatment or suppression of genital herpes in immuno-competent individuals and for the suppression of recurrent genital herpes in HIV infected individuals. It is also indicated for the treatment of cold sores (Herpes labialis).

Adult Dosage:

Cold Sores: 2 grams every 12 hours for 1 day

Genital Herpes:

• Initial episode: 1 gram twice daily for 10 days
• Recurrent episodes: 500 mg twice daily for 3 days Suppressive therapy
• Immunocompetent patients: 1 gram once daily
• Alternate dose in patients with < 9 recurrences/year: 500 mg once daily
• HIV-infected patients: 500 mg twice daily
• Reduction of transmission: 500 mg once daily

Herpes Zoster: 1 gram 3 times daily for 7 days

Pediatric Dosage:

• Cold Sores (> 12 years of age): 2 grams every 12 hours for 1 day
• Chickenpox (2 to < 18 years of age): 20 mg/kg 3 times daily for 5 days; not to exceed 1 gram 3 times daily

Valacyclovir is contraindicated in patients with a known hypersensitivity or intolerance to valacyclovir, acyclovir, or any component of the formulation.

The most frequently reported adverse reactions were nausea (15%), headache (14%), vomiting (6%), dizziness (3%) and abdominal pain (3%).

Dosage reduction is recommended when administering valacyclovir to patients with renal impairment. Similar caution should be exercised when administering valacyclovir to geriatric patients and patients receiving potentially nephrotoxic agents. The safety and efficacy of valacyclovir have not been established in immuno compromised patients other than for the suppression of genital herpes in HIVinfected patients

Use in Special Populations

Pediatric Use: Safety and effectiveness of valacyclovir in pre-pubertal pediatric patients have not been established.

Elderly Use (Over 65 yr.): Elderly patients may require a dose reduction of valacyclovir due to a low body weight or disorders (renal, CNS etc.) associated with aging.

Pregnancy & Lactation

Pregnancy category B. Valacyclovir was not teratogenic in rats or rabbits at 10 and 7 times human plasma levels, respectively, during the period of major organogenesis. There is no adequate and well-controlled studies of valacyclovir in pregnant women.

Nursing Mothers: Unchanged valacyclovir was not detected in maternal serum, breast milk, or infant urine. Valacyclovir should be administered to a nursing mother with caution and only when indicated.