A Study of Valacyclovir Hydrochloride in the Prevention of Life-Threatening Cytomegalovirus Disease in HIV-Infected Patients

PRIMARY: To evaluate the efficacy of valacyclovir hydrochloride (BW 256U87) in the prevention of cytomegalovirus (CMV) end-organ disease in HIV/CMV co-infected patients with CD4+ lymphocytes < 100 cells/mm3. To assess the impact of BW 256U87, high-dose oral acyclovir and low-dose oral acyclovir on survival. SECONDARY: To evaluate the effect of BW 256U87 on quality of life, the safety of the drug administered concurrently with standard antiretroviral agents and other essential therapies for the treatment and prevention of opportunistic diseases, and the efficacy of BW 256U87 in suppressing activation of other herpesviruses. To evaluate serologic and virologic risk factors for the development of CMV disease, including assessment of HIV activation, and the risk of developing drug-resistant CMV, HSV, and VZV. Gastrointestinal absorption of acyclovir is not high enough to prevent CMV disease in patients with advanced HIV disease, although there is evidence that high doses of the drug may extend survival. Valacyclovir, a prodrug that is rapidly converted to acyclovir after oral administration, has a higher absorption rate and may therefore provide inhibitory activity against CMV. Gastrointestinal absorption of acyclovir is not high enough to prevent CMV disease in patients with advanced HIV disease, although there is evidence that high doses of the drug may extend survival. Valacyclovir, a prodrug that is rapidly converted to acyclovir after oral administration, has a higher absorption rate and may therefore provide inhibitory activity against CMV. Patients are randomized to receive BW 256U87 alone or acyclovir alone as control at either high-dose or low-dose. The acyclovir controls will provide suppressive therapy for herpes simplex infections and may affect survival.