Valtrex (valacyclovir HCl)

The following drug information is obtained from various newswires, published medical journal articles, and medical conference presentations.


Approval Status:

Approved December 1995

Specific Treatments:

herpes simplex

General Information

Valtrex has been approved as a treatment for recurrent genital herpes (herpes simplex) in otherwise healthy (immunocompetent) adults. The efficacy of Valtrex has not been established in immunocompromised subjects.

Clinical Results

In clinical trials, Valtrex shortened the healing time of genital herpes sores by 33% on average compared to placebo. The duration of pain associated with genital herpes was reduced by 25% in subjects who received Valtrex as opposed to placebo. Valtrex also stopped viral shedding 50% faster on average than placebo. Viral shedding is the process in which virus is released from the skin during an outbreak of genital herpes.

Valtrex has been shown to be effective when administered within 24 hours of the first sign or symptom of a recurrent genital herpes outbreak.

Side Effects

Valtex was generally well tolerated, with the most common adverse events consisting of headache, nausea, diarrhea, and dizziness.

Mechanism of Action

Valtrex is rapidly and extensively converted to acyclovir after oral administration. The drug delivers three to five times higher blood levels of acyclovir than oral Zovirax.

Additional Information

As many as 31 million Americans are infected with the virus that causes genital herpes and up to 500,000 new cases occur each year.

Genital herpes is a recurrent, infectious disease caused by the herpes simplex virus. A sexually transmitted disease, genital herpes is spread through direct body contact when sores are present. However, research shows that the virus can also be transmitted in the absence of symptoms through asymptomatic viral shedding. Once infected, the virus remains in the body for the person's lifetime.

Genital herpes is characterized by blister-like sores on the genitals or buttocks that reactivate periodically. The frequency of recurrent outbreaks varies from person to person. Generally they occur an average of four to six times each year, but can recur as often as once a month. If recurrent outbreaks are left untreated, sores usually last from seven to ten days. If medical management of a genital herpes recurrence is indicated, subjects should be advised to initiate therapy at the first sign or symptom of an episode. Recurrent outbreaks may become less frequent and less severe over time.