[Risk factors and prevention of pneumocystis carinii pneumonia after bone marrow transplantation]

For six months after bone marrow transplantation (BMT) there is a risk of 5 to 15% to suffer from interstitial pneumonia due to pneumocystis carinii (PcP). Prophylaxis with trimethoprim/sulfamethoxazol is therefore routinely and successfully applied. However myelotoxicity, allergic reactions, augmentation of the risk of nephrotoxicity with cyclosporine A and noncompliance may be serious problems. Since the prophylaxis of PcP with pentamidine-aerosol proved to be effective in patients with AIDS, we conducted a prospective trial with regular inhalations of pentamidine. The aim of this study was to evaluate the toxicity, safety, practicability and possible resorption of pentamidine when applied as aerosol. The first of 43 patients were treated with 60 mg pentamidine on two days before, at the day of BMT and 14 days after BMT. Starting four weeks after BMT, 300 mg pentamidine were given every four weeks up to six months. After the study, the four 60 mg inhalations were replaced by two 300 mg inhalations before BMT, because this proved to be more convenient for the patients. There was no pneumonia due to pneumocystis carinii. The only noteworthy side effects observed were cough (19.8%), salivation (9.6%) and sore throat (5.7%). In general pentamidine was well tolerated and well accepted by the patients. Pentamidine could only be detected in the serum of 40 to 60% of all patients. In those patients the serum levels were 7.5 to 9 ng/ml and similar to concentrations found in comparable patients with AIDS. We conclude, that pentamidine-aerosol has only minor side effects, is well tolerated and safe and is therefore an attractive alternative for PcP-prophylaxis after BMT.