Chemoprophylaxis of viral infection in immunocompromised patients.

Viral infections are of increasing importance in the compromised host, particularly herpesvirus infections. Both intravenous and oral acyclovir are effective in preventing reactivation of herpes simplex virus infection; oral regimens are less expensive but compliance may be problematic. Varicella zoster virus reactivation can be suppressed for 6-12 months after marrow transplant using oral acyclovir, although infection may occur at the usual rate when prophylaxis is stopped. Intravenous acyclovir given for 30 days after marrow transplant reduced cytomegalovirus disease by 50%. New agents such as ganciclovir or foscarnet promise better control of cytomegalovirus infection.