C. diff Risk


Oral Bioavailability


Approximate Cost

Spectrum Of Activity

General Information

Common Usage

For the treatment of herpes zoster (shingles).

For the treatment or suppression of genital herpes in immunocompetent individuals and for the suppression of recurrent genital herpes in HIV infected individuals.

To reduce the risk of transmission of genital herpes with the use of suppressive therapy.

For the treatment of cold sores (herpes labialis).

Adverse Effects



Acute kidney injury.

Increased AST and ALT.

CNS effects (agitation, hallucinations, confusion and encephalopathy).

Thrombotic Thrombocytopenia Purpura/Hemolytic Uremic Syndrome (TTP/HUS).

Major Interactions

No clinically significant interactions have been identified. Screen drug specific interactions for interactions via CYP 1A2 and pharmacodynimc adverse effects.

Increased risk of nephrotoxicity when used concomitantly with other nephrotoxic agents.

Additional Information

ValACYclovir is a prodrug of the antiviral acyclovir. ValACYclovir is rapidly and nearly completely converted to acyclovir, which has inhibitory activity against human herpes simplex virus HSV-1, HSV-2 and varicella zoster virus (VZV).

Patients should remain adequate hydration to prevent acute kidney injury while taking ValACYclovir.


Pharmacology: Antiviral agent

Pregnancy category: B

Average serum half life: ValACYclovir: ~30 minutes; acyclovir: 2.5-3.3 hours

CSF penetration: 50% of serum concentrations