Long acting Beta Blockers have been used since long to control asthma. Here is a study of LABA usage.

Team@CMHF

Children who stopped taking long-acting beta agonists (LABAs) once their asthma was controlled had a 37% chance of losing that control, according to a study presented here at the American College of Allergy, Asthma & Immunology 2011 Annual Scientific Meeting.

In 2010, the US Food and Drug Administration (FDA) recommended that patients with asthma who are controlled on LABAs discontinue therapy because of concerns about the safety of LABAs. This recommendation is in accordance with guidelines from the National Heart, Lung, and Blood Institute, Dr. O’Hagan told Medscape Medical News. “There are very few data on step-down therapy for LABAs, particularly in pediatrics, so we wanted to see what would happen when we discontinued the therapy,” he said.

Dr. O’Hagan and his group studied 54 patients, between the ages of 6 and 17 years, with moderate to severe persistent asthma who regularly attended the pediatric pulmonary outpatient asthma clinic at Kosair Children’s Hospital in Louisville. All patients were taking combination inhaled corticosteroids and LABAs.

After patients had achieved normal or near-normal spirometry and an asthma control test score greater than 20, LABAs were discontinued; however, the same bioequivalent dose of the inhaled corticosteroid was maintained.

A little more than 2 months after stopping LABAs, just over one third of patients who had discontinued LABA therapy had a worsening of their asthma, based on symptom scores, lung function, and the need for systemic steroids because of exacerbations, Dr. O’Hagan reported.

After a mean follow-up of 10.7 weeks, 20 patients (37%) had a loss of asthma control, necessitating treatment with a leukotriene-receptor antagonist in 1 patient, an increase in the dose of inhaled corticosteroids in 1 patient, and restarting LABA treatment in 18 patients.

In addition, 2 patients had exacerbations of their asthma that required systemic steroids. Children with asthma exacerbations experienced a statistically significant decline in forced expiratory volume in 1 second (8.0% vs 1.9%; P = .03) and asthma control test scores (3.2 vs 0.5; P = .03).

“This is a small sample, and larger trials are needed to determine the best way to step down therapy,” Dr. O’Hagan noted. “But it’s useful to know that this can happen.”
Medscape Medical News invited Gailen Marshall, Jr., MD, PhD, from the University of Texas Medical School in Houston, to comment on the study.

“The step-down recommendations for LABA in asthma patients once control is achieved is a largely theoretical argument, based on FDA warning labels that suggest an increased mortality risk with continued use of LABAs,” Dr. Marshall noted.

The addition of LABAs to inhaled corticosteroids should not occur unless the patient is deemed to be not well controlled on standard doses of inhaled corticosteroids, he said. “This study suggests that there is a distinctive subgroup that requires a LABA/inhaled corticosteroid combination to not only achieve but to maintain control,” he said.

Dr. Marshall agrees that further study is needed to identify the specific subpopulation of asthma patients for whom LABA therapy is a necessary long-term component of care.

Ref: http://www.medscape.com/viewarticle/753861?src=mp&spon=34