Effects of long-term aerosol pentamidine for Pneumocystis carinii prophylaxis on pulmonary function.

OBJECTIVE

The purpose of the study was to evaluate the long-term effects of aerosolized pentamidine (AP) on the pulmonary function of HIV-positive individuals receiving AP for Pneumocystis carinii pneumonia (PCP) prophylaxis.

DESIGN

A retrospective analysis of serial pulmonary function tests (PFTs) performed on a cohort of HIV-positive patients who had received AP for >2 years.

METHODS

Of the 1,787 HIV-positive patients receiving AP prophylaxis in our database, 380 patients had been receiving AP for at least 24 months. Of these 380 patients, the PFTs at baseline and at 24 months after starting AP therapy were documented in 179. We compared the baseline PFTs of these 179 patients with results obtained 24 months later to evaluate if there was any change in pulmonary function parameters.

RESULTS

Baseline and 24-month PFT parameters (total lung capacity [TLC], FVC, residual volume [RV], FEV1, FEV1/FVC, maximum midexpiratory flow rate at 50% of vital capacity [MEF50], diffusion of carbon monoxide [DLCO]) were all within the normal ranges. However, AP therapy over 24 months was associated with a modest decline in lung volume parameters (TLC, FVC, RV), a slight reduction in flow rates (FEV1, FEV1/FVC, and MEF50), but no change in DLCO. The mean treatment duration was 23.8 months (range, 21 to 27 months).

CONCLUSIONS

Long-term AP therapy is associated with a mild combined restrictive and obstructive pulmonary defect. Since 24-month PFT parameters remained within the normal ranges, this level of decline is of unclear clinical significance. Overall, AP has good pulmonary tolerance when used up to 24 months for PCP prophylaxis in patients with normal baseline pulmonary function.