Treatment and prophylaxis of Pneumocystis carinii pneumonia in AIDS patients.

Pneumocystis carinii pneumonia (PCP) is seen in people with a defect in cell-mediated immunity. Today the most common cause for this is the Acquired Immunodeficiency Syndrome (AIDS). There have been some remarkable advances recently in the development of new drug regimens to combat this otherwise fatal infection. Although cotrimoxazole (trimethoprim-sulfamethoxazole) is still the drug of first choice it cannot be tolerated by a significant proportion of patients, and therapies such as pentamidine (pentamidine-isethionate) [intravenous or nebulised], dapsone-trimethoprim, eflornithine (DFMO; difluoromethylornithine), trimetrexate, and clindamycin-primaquine are finding therapeutic niches. The major advantage in these other agents is not improved efficacy but different toxicity profiles, enabling therapy to be most appropriately tailored to individual patients' conditions. Although the majority of patients should now survive an attack of PCP, relapses will occur if prophylaxis is not used. There is also the capacity to predict accurately which patients are at risk for this pneumonia and prevent it through the use of chemoprophylaxis. These advances in the treatment and prevention of PCP, together with anti-retroviral therapy, mean that this is an area of AIDS management that has resulted in improved long term survival.