Bronchodilator Pretreatment Improves Aerosol Deposition Uniformity in HIV-Positive Patients Who Cough While Inhaling Aerosolized Pentamidine

¹ From the Divisions of Infectious Diseases and Radiation Health Sciences, Johns Hopkins Medical Institutions, Baltimore

Objective: To determine the effect of bronchodilator pretreatment on deposition uniformity of aerosolized pentamidine (AP) in HIV-positive patients who coughed while inhaling AP.

Design: Nonrandomized control trial.

Setting: A university hospital.

Patients: Ten HIV-positive patients who were using AP prophylactically.

Intervention: Four patients who coughed during AP administration were pretreated with 10 mg metaproterenol aerosol prior to a second inhalation of AP.

Measurements: Skew, a measure of overall deposition symmetry, deposition in the apex vs the base of the right lung (A:B ratio), and percentage of change from baseline in peak expiratory flow rate (PEFR).

Results: At baseline, the average (±SD) skew value for four subjects who coughed (0.89±0.19) was significantly higher than for six control subjects (0.58±0.07) (p<0.01), indicating enhanced nonuniformity of AP distribution. After bronchodilator, no one coughed and the average skew value was normalized to 0.57±0.13. The A:B ratios at baseline and after metaproterenol were not significantly different, suggesting that deposition of AP in the apex, relative to basal deposition, was not enhanced by bronchodilator treatment. When no bronchodilator was administered, average PEFR decreased to 330±162 from baseline (410±84). Average PEFR increased to 429±85 from baseline (395±116) after bronchodilator pretreatment.

Conclusions: These results suggest that in addition to relieving cough in patients receiving AP prophylactically, pretreatment with metaproterenol enhances uniformity of distribution of AP and improves PEFR.