RESPIRATORY EFFECTS OF OCCUPATIONAL EXPOSURE TO AEROSOLIZED PENTAMIDINE

To determine the respiratory effects on health care workers of occupat ional exposure to aerosolized pentamidine (AP) used for the prophylaxi s of Pneumocystis carinii pneumonia, we designed a clinical prospectiv e study using subjects as their own controls. Sixteen health care work ers whose job duties included administration of AP at one or more of n ine San Francisco Bay Area medical centers participated in the study. Pentamidine concentrations ranged in breathing zone samples from <0.03 to 62.2 mug/m3. Pentamidine was not detected in the urine of any of t he subjects. There were no significant increases in symptoms on days w hen AP was administered. Cross-workshift spirometry on days when AP wa s administered showed a statistically significant mean decrease (0.14 liter) in forced expiratory volume in 1 second. There was no statistic ally significant difference in mean diurnal variation of peak expirato ry flow rate on days when AP was administered. Methacholine inhalation challenge testing did not show a statistically significant mean chang e in airway responsiveness across the workweek. The ambient concentrat ions of pentamidine that we measured document that detectable occupati onal exposure to AP can occur in poorly ventilated treatment rooms. Th e cross-workshift decrement in forced expiratory volume in 1 second th at we observed in association with AP administration supports the resp iratory tract irritant potential of inhaled pentamidine. We recommend that steps be taken to minimize health care worker exposure to AP.