Valacyclovir (Valtrex) -
Valacyclovir is an L-valyl ester of acyclovir that is metabolized to acyclovir after oral administration, resultingin higher serum concentrations than with oral acyclovir. Acyclovir serum concentrations following high doses of oral valacyclovir resemble those following IV administration of acyclovir. A one-day treatment regimen of valacyclovir reduced the duration of oral herpes by about 1 day. In first-episode or recurrent genital herpes, vala cyclovir twice daily is as effective as acyclovir given 5 times a day. Valacyclovir 500 mg once daily is effective for suppression of genital HSV and one study of discordant couples found that 8 months of suppressive valacyclovir taken by the infected partner decreased the risk of HSV transmission to the susceptible partner by about half may be required for suppression in patients with frequent recurrences.