VALACICLOVIR - AN IMPROVED TREATMENT FOR INDIVIDUALS WITH HIV AIDS

Aciclovir is a first-line therapy for the management of herpes simplex Virus (HSV) and varicella tester virus (VZV) infections in individuals with human immunodeficiency virus (HIV)/AIDS. Recent studies have also confirmed a survival benefit from aciclovir combined with antiretroviral therapy in people with advanced HIV infection. Although the precise mechanism for this effect is uncertain, it is thought likely to be related to the antiherpes activity of aciclovir. Oral aciclovir has not been shown to affect clinically apparent cytomegalovirus (CWV) disease in individuals with AIDS, but has demonstrated a modest benefit against Epstein-Barr virus (EBV) disease manifested as oral hairy leukoplakia. Whilst aciclovir is the mainstay of current therapy for herpes infections other than CMV, there are several limitations of the therapy which relate principally to the poor absorption of oral drug. oral aciclovir must be given five times daily, yet this may not always be adequate to control or suppress herpes infections. Development of resistance to aciclovir can be clinically relevant for both HSV and VZV in more severely immunocompromised patients at later stages of HIV infection. The substantial improvement in bioavailability of aciclovir, following oral administration of valaciclovir, offers a means of overcoming the limitations of oral aciclovir whilst hopefully maintaining the safety profile of the parent drug. The enhanced plasma levels of aciclovir may also be sufficient to impact on the development of CMV disease.