The U.S. Food and Drug Administration (FDA) has warned healthcare professionals regarding the increased risk of severe asthma episodes and death associated with use of inhalation powders containing long-acting beta 2-adrenergic agonists (LABA) such as salmeterol xinafoate and formoterol fumarate.
Inhalation powders included in the warning include salmeterol (Serevent Diskus, made by GlaxoSmithKline), salmeterol combined with fluticasone propionate (Advair Diskus, made by GlaxoSmithKline), and formoterol (Foradil Aerolizer, made by Novartis Pharmaceuticals Corp.).
Patients receiving these medications should be advised to seek medical attention immediately if their asthma worsens, according to an alert sent today from MedWatch, the FDA’s safety information and adverse event reporting system.
The warning was based on data from a 28-week clinical trial (Salmeterol Multi-center Asthma Research Trial [SMART]) in 26,355 patients, showing that addition of salmeterol to usual asthma therapy was associated with an increased risk of fatal asthma events compared with placebo (13 vs 3 deaths; 0.10% vs 0.02%). These results led to early discontinuation of the study.
Although post-hoc subpopulation analyses suggested that the relative risk (RR) of death was similar among whites (RR, 5.82; 95% confidence interval [CI], 0.70 – 48.27) and African Americans (RR, 7.26; 95% CI, 0.89 – 58.94), incidence rates were higher among African Americans.
The results from SMART were similar to those of the Salmeterol Nationwide Surveillance (SNS) study in 25,180 patients, showing the incidence of respiratory and asthma-related death to be numerically (though not statistically) greater with addition of salmeterol rather than albuterol to usual asthma therapy (12 vs 2 deaths).
Although no studies have been adequate to determine whether formoterol is also associated with an increased rate or relative risk of asthma-related death, smaller studies have linked its use to an increased incidence of serious asthma exacerbations compared with albuterol and placebo.
Healthcare professionals with asthma patients receiving these medications should be aware that LABAs are not intended as first-line therapy and should be reserved for use in those who have demonstrated an inadequate response to other asthma-controller medications such as inhaled corticosteroids.
Current guidelines from the National Heart, Lung, and Blood Institute and World Health Organization recommend inhaled corticosteroids as the first step in controller therapy, with LABAs as optional add-on therapy if low- to medium-dose inhaled corticosteroids provide inadequate relief.
The FDA notes that the warning applies to use of LABAs for the long-term control and prevention of asthma symptoms. Information is not available to determine the relevance of these findings in patients using LABAs for the prevention of exercise-induced bronchospasm or long-term control of bronchospasm due to chronic obstructive pulmonary disease.
Adverse events related to the use of long-acting beta 2-agonists should be reported to the FDA’s MedWatch program by phone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at http://www.fda.gov/medwatch, or by mail to 5600 Fishers Lane, Rockville, MD 20852-9787.