Cumulative dose-response study of non-CFC propellant HFA 134a salbutamol sulfate metered-dose inhaler in patients with asthma.

STUDY OBJECTIVE

This study compares the safety and efficacy of HFA 134a salbutamol sulfate (Airomir in the 3M CFC-free system [3M Pharmaceuticals]) and CFC 11/12 salbutamol (Ventolin [Allen & Hanburys]) in a cumulative dose-response (1, 1, 2, 4, 8 inhalations at 30-min intervals) study in asthmatic patients.

DESIGN

Randomized, single-blind, two-period cross-over study.

PARTICIPANTS

Twenty-four stable mild to moderate asthmatics.

MEASUREMENTS AND RESULTS

At all cumulative inhalations, the changes in FEV1 (absolute, percent, and percent predicted) and FVC were equivalent. There was also no significant difference in heart rate, serum potassium level, BP, 12-lead ECG, Holter monitor recordings, or adverse events. Both HFA 134a salbutamol sulfate and CFC 11/12 salbutamol displayed a significant dose-response for FEV1, FEF25-75%, FVC, serum potassium, heart rate, and systolic BP.

CONCLUSIONS

HFA 134a salbutamol sulfate and CFC 11/12 salbutamol produced clinically and statistically similar airway responses and side effects. These results indicate that HFA 134a salbutamol sulfate would be a safe and effective substitute for CFC 11/12 salbutamol.