Prevention of herpes simplex virus infections in susceptible patients.

Immunocompromised patients are at high risk of developing herpes simplex virus infections caused by reactivation of the virus. Intravenous and oral formulations of acyclovir have been shown to prevent most of these infections during the major at-risk periods when given prophylactically. Immunocompetent patients may also experience reactivation of herpes simplex virus leading most often to recurrent genital or labial infections. For those patients who experience frequent attacks, oral acyclovir can prevent most recurrences and is well tolerated when given as continuous suppressive therapy.