Pentamidine. A risk-benefit analysis

With the advent of the acquired immunodeficiency syndrome (AIDS), the therapeutic importance of pentamidine isethionate has greatly increased. This review summarises its pharmacology, its toxicity and clinical experience in the treatment of Pneumocystis carinii pneumonia (PCP). Data are conflicting as to whether pentamidine is more or less effective than cotrimoxazole (trimethoprim-sulfamethoxazole) for the treatment of PCP in individuals with AIDS, but due to its toxicity and expense, it is considered as second-line therapy by many authorities. Hypoglycaemia has been encountered in up to 27% of treatment courses with pentamidine, and nephrotoxicity in 25%. In an attempt to circumvent the toxicities associated with parenteral administration, aerosolised delivery has been evaluated for both therapy and prevention of PCP. Aerosolised pentamidine, on the basis of early clinical results, convenience and low toxicity, may become the drug of choice for prevention of PCP in individuals at high risk. However, its role in the treatment of PCP remains to be defined. Preliminary studies suggest that it is effective, but the data are insufficient to support its use outside of clinical trials.