This paper discusses the introduction of antiretroviral (ARV) therapy to HIV-infected patients. ARV therapy is treatment with drugs that fight the HIV virus and keep the HIV-infected patient healthy. Treatment may involve only one ARV (monotherapy) or a combination of two or more ARVs (combination therapy). The increasing availability of ARVs in many countries has caused dangerous side effects to develop quickly in patients due to the improper use of drug combinations. Some life-threatening side effects of ARV misuse include vomiting, diarrhea, fever, diabetes, and pancreatitis. People who experience these symptoms need to change their drug combination; a drug must be taken with strict instructions to prevent unpleasant side effects and its reaction with other drugs (protease inhibitors, for example, react with the tuberculosis drug rifampicin). An ARV should also be closely monitored to ensure its continuous effectiveness using CD4 and viral load counts at least every 3-6 months. A change in drug combination is required when CD4 count is dropping or the viral load is not reduced or maintained.