Study objectives: To assess the effects of long-term exposure to aerosolized pentamidine (AP) for the prophylaxis of Pneumocystis carinii pneumonia on the pulmonary function.
Design: The results of pulmonary function tests (PFTs) over a period of 5 years were retrospectively analyzed in a cohort of HIV-infected individuals.
Setting: A government-funded AP clinic in a large metropolitan center in Canada.
Patients: Among the cohort of 1,850 HIV-positive patients who received regular AP prophylaxis between 1989 and 2001 at the AP clinic, 83 received AP for ≥ 5 years. Of these 83 patients, baseline and long-term follow-up PFT data were available for 79. These subjects formed the study population for this analysis.
Results: The cohort was divided according to smoking status (smokers, 48%). The rate of decline of FEV1 in the smokers over the 5-year period was statistically significant but was comparable to that expected of healthy smokers. As for the nonsmokers, there was no significant reduction in FEV1. Flow rates at low lung volumes (ie, forced expiratory flow at 50% and 75% of FEV1) and low FEV1/FVC ratios showed significant declines in both smokers and nonsmokers. On the other hand, no significant changes in FVC, total lung capacity, residual volume, or diffusing capacity of the lung for carbon monoxide were observed. The apparent slight reduction in flow rates seems to be at the level of the small airways.
Conclusions: The PFT data suggest that AP can be well-tolerated over a 5-year period in HIV-infected patients with only modest reduction in flow rates at the level of the small airways, especially in smokers.