General Information

Proventil HFA (albuterol sulfate) Inhalation Aerosol is a relatively selective beta2-adrenergic bronchodilator.

Proventil HFA is indicated in adults and children 4 years of age and older for the treatment or prevention of bronchospasm with reversible obstructive airway disease and for the prevention of exercise-induced bronchospasm.

For treatment of acute episodes of bronchospasm or prevention of asthmatic symptoms, the usual dosage for adults and children 4 years of age and older is two inhalations repeated every 4 to 6 hours. More frequent administration or a larger number of inhalations is not recommended. In some patients, one inhalation every 4 hours may be sufficient. Each actuation of Proventil HFA Inhalation Aerosol delivers 108 mcg of albuterol sulfate (equivalent to 90 mcg of albuterol base) from the mouthpiece.

Exercise Induced Bronchospasm Prevention: The usual dosage for adults and children 4 years of age and older is two inhalations 15 to 30 minutes before exercise.

Mechanism of Action

Proventil HFA (albuterol sulfate) Inhalation Aerosol is a relatively selective beta2-adrenergic bronchodilator. In vitro studies and in vivo pharmacologic studies have demonstrated that albuterol has a preferential effect on beta2-adrenergic receptors compared with isoproterenol. While it is recognized that beta2-adrenergic receptors are the predominant receptors on bronchial smooth muscle, data indicate that there is a population of beta2-receptors in the human heart existing in a concentration between 10% and 50% of cardiac beta-adrenergic receptors. The precise function of these receptors has not been established.

Clinical Trial Results

In a 12-week, randomized, double-blind, double-dummy, active- and placebo controlled trial, 565 patients with asthma were evaluated for the bronchodilator efficacy of Proventil HFA Inhalation Aerosol (193 patients) in comparison to a CFC 11/12 propelled albuterol inhaler (186 patients) and an HFA-134a placebo inhaler (186 patients). Serial FEV1 measurements (shown below as percent change from test-day baseline) demonstrated that two inhalations of Proventil HFA Inhalation Aerosol produced significantly greater improvement in pulmonary function than placebo and produced outcomes which were clinically comparable to a CFC 11/12 propelled albuterol inhaler. The mean time to onset of a 15% increase in FEV1 was 6 minutes and the mean time to peak effect was 50 to 55 minutes. The mean duration of effect as measured by a 15% increase in FEV1 was 3 hours. In some patients, duration of effect was as long as 6 hours. In another clinical study in adults, two inhalations of Proventil HFA Inhalation Aerosol taken 30 minutes before exercise prevented exercise-induced bronchospasm as demonstrated by the maintenance of FEV1 within 80% of baseline values in the majority of patients.

In a 4-week, randomized, open-label trial, 63 children, 4 to 11 years of age, with asthma were evaluated for the bronchodilator efficacy of Proventil HFA Inhalation Aerosol (33 pediatric patients) in comparison to a CFC 11/12 propelled albuterol inhaler (30 pediatric patients). Serial FEV1 measurements as percent change from test-day baseline demonstrated that two inhalations of Proventil HFA Inhalation Aerosol produced outcomes which were clinically comparable to a CFC 11/12 propelled albuterol inhaler. The mean time to onset of a 12% increase in FEV1 for Proventil HFA Inhalation Aerosol was 7 minutes and the mean time to peak effect was approximately 50 minutes. The mean duration of effect as measured by a 12% increase in FEV1 was 2.3 hours. In some pediatric patients, duration of effect was as long as 6 hours. In another clinical study in pediatric patients, two inhalations of Proventil HFA Inhalation Aerosol taken 30 minutes before exercise provided comparable protection against exercise induced bronchospasm as a CFC 11/12 propelled albuterol inhaler.