Microbicides for the prevention of sexually transmitted HIV infection.

The impetus for, and efforts in the past 20 years toward a women-initiated method for preventing sexual transmission of HIV has been previously well described. To date, four classes of topical agents categorized by mechanism of action as: surfactants, buffers, cell entry blockers and antiretroviral agents have undergone advanced clinical testing. Thus far, only coitally linked use of 1% tenofovir gel has demonstrated moderate effectiveness in preventing HIV and HSV-2 infection and has generated renewed hope for microbicide development. Studies of new antiviral agents, novel delivery mechanisms and combination/multipurpose products that address challenges of adherence and enhance the effectiveness of tenofovir gel are already underway to further enhance sexual and reproductive health needs of men and women and efforts to prevent HIV infection.