New targets and new drugs in the treatment of HIV.

Antiretroviral treatment has modified the course of human immunodeficiency virus (HIV) infection transforming it into a chronic disease. However, as treatment is conceived "for life", more effective and safety drugs, overcoming the growing resistance of the virus are required. New molecules may block the known viral targets or other new ones. The mechanism of the virus union and entrance to the cell includes the new therapeutic targets that are studied more frequently. Although studies with substances that efficiently block the virus-CD4 receptors union are in very early phases, other studies of molecules capable to block the entrance co-receptors are in more advanced phases (II or III), and enfuvirtide, a substance that blocks membrane fusion, the last phase of virus entrance, has been recently marketed. Another very promising pharmacological target is the integration of the proviral DNA as we know some substances that in vitro block HIV integrase. Besides this, new drugs are increasing the three classic antiretroviral families. Among nucleoside analogs emtricitabine (recently marketed) and amdoxovir are the more prominent. Capravirine and TMC-125 are the non-nucleoside analogs whose studies are more advanced. And atazanavir, fos-amprenavir, tipranavir and TMC-114 are the new protease inhibitors recently marketed or near to be.