Current treatment of HIV infection.

The field of antiretroviral therapy has witnessed remarkable progress during the past 15 years. There are now over a dozen approved therapeutic agents for infection with the human immunodeficiency virus (HIV), a pathogen that once caused nearly uniformly fatal illness. These agents usually target two essential enzymes of the virus, the reverse transcriptase and the protease. The era of potent antiretroviral therapy, also termed highly active antiretroviral therapy, began in 1996 and has been marked by dramatic declines in morbidity and mortality due to HIV disease in the developed world. These advances have not been without their cost in terms of drug resistance and toxicity and unwanted effects. Concern about these negative effects has led to a more conservative approach to the timing of the initiation of therapy and to clinical trials of intermittent therapy in an attempt to decrease the total exposure to drugs over time. Immune-based approaches such as therapeutic vaccination may someday permit viremia to be controlled in the absence of drugs. Antiviral potency has been the key to the initial success of drug regimens, as well as to the durability of their success, the restoration of immune function, the prevention of the emergence of resistance, and ultimately the prevention of disease progression. Future progress in antiretroviral therapy will bring more choices for physicians and patients and will make an already complex field both more challenging and more rewarding.