The introduction of antiretroviral therapy to clinical practice has assured a significant improvement in the quality of life for people living with HIV infection, and has substantially prolonged their life expectancy. At present there are four classes of antiviral drugs in clinical use and several new promising molecules are in various stages of clinical research and development. The major problems with current antiretroviral therapy are the occurrence of serious side-effects and a relatively quick development of resistance. Good cooperation between the patient and the physician is essential for the success of antiretroviral therapy. This success is based primarily on careful monitoring of side-effects by the physician and maximum adherence by the patient. The new antiretroviral drugs under development are thus expected to háve lower toxicity and lower sensitivity to the development of viral resistance. The new drugs should be also cheaper because, due to the high costs of the antiretroviral drugs that are currently being ušed, only about 25 % of all people indicated for treatment worldwide have access to therapy.

        Key words: HIV, AIDS, therapy, resistance, side-effects.