EFFECT OF LONG-TERM PRIMARY AEROSOLIZED PENTAMIDINE PROPHYLAXIS ON BREAKTHROUGH PNEUMOCYSTIS-CARINII PNEUMONIA

Aerosolized pentamide is a well-tolerated primary prophylaxis regimen for Pneumocystis carinii pneumonia (PCP) in human immunodeficiency vir us (HIV)-infected patients, It is now commonly administered for prolon ged periods, We therefore studied the effect of long-term inhalation o n breakthrough PCP. We recorded clinical, immunological, radiological and microbiological data, as well as therapy and clinical course of al l episodes with confirmed PCP diagnosed at our institution between Jan uary 1, 1990 and June 30, 1995, Furthermore, data of all patients on p rimary aerosolized pentamidine since May 1, 1989 were retrieved, Proph ylaxis failures were subdivided into ''early'' (less than or equal to 12 months of inhalation time) and ''late'' (>12 months of inhalation t ime) failures and were compared with episodes without any prophylaxis. Thirty patients without any prophylaxis, six with early and 14 with l ate failures represented the study population, Mean+/-SD inhalation ti mes were 4.9+/-4.8 and 26.3+/-14.1 months, respectively, No significan t differences could be detected with regard to clinical presentation, severity of PCP, and in-hospital as well as long-term outcome, Early a s well as late prophylaxis failures had a higher incidence of upper lo be infiltrates on chest radiography (50% without prophylaxis versus 10 0% with early and 83% with late failure, respectively; p<0.05), No ext rapulmonary or disseminated pneumocystosis was observed in either grou p, The sensitivity of site-directed bronchoalveolar lavage was conserv ed after long-term inhalation (86% versus 100% without prophylaxis and 97% in early failure; p=NS). The severity and outcome of Pneumocystis carinii pneumonia is not altered by long-term primary aerosolized pen tamidine prophylaxis, Presentation with upper lobe infiltrates is a ra diographic pattern also of late failures, Bronchoalveolar lavage shoul d, therefore, be performed using the site-directed technique in this s etting.