A prospective comparison of Porta-sonic and Fisoneb ultrasonic nebulizers for administering aerosol pentamidine.

OBJECTIVE: To report patient acceptability and overall therapeutic effectiveness of two different ultrasonic nebulizers, Fisoneb and Porta-sonic, for the administration of aerosol pentamidine for Pneumocysitis carinii prophylaxis in human immunodeficiency virus (hiv)-infected individuals. DESIGN: Prospective assessment of a random subgroup of 174 individuals from an inception cohort of 1093 patients attending a central aerosol pentamidine treatment centre in Toronto, Ontario. METHODS: One hundred and seventy-four patients who had been receiving aerosolized pentamidine for more than 10 weeks using Fisoneb at 60 mg every two weeks were switched to Porta-sonic. Subjective evaluation included three standard 10 cm visual analogue scales rating cough/wheeze, aftertaste and overall preference. The individuals were also asked to compare the duration of time spent on the aerosol treatments. Objective evaluation included spirometry performed immediately before and 15 mins after pentamidine administration. Prospective surveillance of the entire cohort was preformed to record and document episodes of breakthrough P carinii pneumonia. RESULTS: Porta-sonic was the overall preferred nebulizer in 82% of patients. Less time was spent on aerosol treatment using the Porta-sonic nebulizer compared with the Fisoneb in 66% of patients. The Porta-sonic nebulizer system produced less aftertaste compared with Fisoneb. Both nebulizers produced significant but modest reduction in flow rates. During the study period there was no statistically significant difference in the rates of breakthrough P carinii pneumonia between the two groups. A total of 91 episodes occurred, at a rate of 0.5 episodes per patient-month on Porta-sonic compared with 0.7 episodes per patient-month on Fisoneb (P=0.2536). DISCUSSION: Aerosol pentamidine remains the proven second-line prophylaxis against P carinii pneumonia in hiv/aids for those intolerant to trimethoprim-sulphamethoxazole. Cough, bronchospasm and poor taste are side effects that may limit patient tolerance and acceptability. The results of this study show that the Porta-sonic nebulizer system significantly reduces some of these side effects and increases patient preference. CONCLUSION: This study suggests that Porta-sonic, the newer nebulizer system, with more ideal in vitro characteristics may become a favoured device in clinical practice.