Hidrofluoralcano como propelente dos aerossóis pressurizados de dose medida: histórico, deposição pulmonar, farmacocinética, eficácia e segurança

Abstract

Objective: To review the literature about hydrofluoroalkane as a propellent of pressurized metered-dose inhalers containing anti-asthma drugs.Sources of data: Bibliographic search in electronic databases (MEDLINE, MDConsult, HighWire, Medscape and LILACS) and direct search referring to the past 15 years, using the key words hydrofluoroalkane, asthma and childhood were carried out.Summary of the findings: 43 original articles on the replacement of clorofluorcarbon by hydrofluoralkane were selected. Hydrofluoralkane showed to be a safe propellent, with pulmonary deposition ranging from 50 to 60%, and to have significant efficacy, when compared with placebo (p < 0.003) in controlled clinical trials. Most works using hydrofluoralkane included beclomethasone diproprionate. Approximate annual cost of a treatment with beclomethasone diproprionate/hydrofluoralkane was lower than with beclomethasone diproprionate/clorofluorcarbon. Some studies assessed salbutamol, fluticasone, flunisolide and the association fluticasone-salmeterol, with hydrofluoralkane as propellent in pressurized metered-dose inhalers.Conclusions: Efficacy and safety of hydrofluoralkane as propellent of bronchodilators and inhaled corticosteroids in adults was evidenced, as well as, in general, there was a better pulmonary deposition of particles. However, literature data on the use of hydrofluoralkane in the paediatric age group are still scarce and further studies with children and adolescents would be of great importance.

Advances in inhalation therapy in pediatrics

“…Ibiapina et al 47 publicaram uma extensa revisão a respeito do uso dos HFA como propelentes para esses dispositivos. Observa-se que as formulações que utilizam beclometasona com HFA, comparadas às que contêm CFC, produzem aerossóis de velocidade mais lenta, com partículas menores e que propiciam maior deposição pulmonar.…”

“…Esse aumento de deposição pulmonar também foi observado com outras drogas, como a fluticasona e a flunisolida. Dados iniciais também indicam que o HFA pode ser uma opção economicamente vantajosa 47 .…”