Combo drug for childhood asthma appears safe
Lingering safety concerns regarding an asthma drug for children may be put to rest by new clinical trial results showing the widely used medication is safe, according to a new report.
Long-acting beta agonists (LABAs) provide short-term relief of asthma symptoms by relaxing and opening the airways. They're prescribed to child asthma sufferers in combination with an inhaled steroid drug to reduce airway inflammation, said study co-author Dr Stanley Szefler. He is director of paediatric asthma research for the University of Colorado School of Medicine.
"Together they have a dual purpose, one to reduce inflammation and the other to open up the airways to make it easier to breathe," Szefler said.
But a 2008 analysis by the US Food and Drug Administration questioned the safety of LABAs, noting that some studies had found an increased risk of asthma-related deaths in adults and asthma-related hospitalisations in children.
Based on the analysis, the FDA slapped a "boxed warning" label on the drugs, which calls attention to serious or life-threatening risks. The agency also asked GlaxoSmithKline, the manufacturer of a LABA intended for children, to perform a large-scale safety trial for its product, researchers said in background information.
A valuable option
The clinical trial, conducted by Szefler and his colleagues, found that children using a combination LABA/steroid inhaler – sold as Glaxo's Advair Diskus – did not have any greater risk of harm than children using an inhaler loaded only with a steroid.
The results have been forwarded to the FDA, which now will decide whether to lift the black box warning, Szefler said.
"The next step is for the FDA to assemble all the available studies, make their own interpretation and determine how that would affect product labelling," he said.
The LABA/steroid combination drug is a valuable option that asthma doctors often use when inhaled steroids alone don't help kids with chronic asthma, said Dr Alfin Vicencio, chief of paediatric pulmonology at Mount Sinai Hospital in New York City.
The boxed warning has impeded use of that option, he said.
No deaths or emergencies
"Not infrequently, families whose children could benefit from this medication decline on the medication specifically because of that warning," Vicencio said. "This manuscript not only gives physicians a little more reassurance, but parents as well."
In the safety trial, researchers recruited more than 6,200 children between 4 and 11 years old. They were randomly assigned inhalers containing a combination of salmeterol (a LABA) and fluticasone (a steroid), or fluticasone alone.
Of all the patients, 27 in the combination drug group had a serious asthma-related event that required hospitalisation, compared with 21 in the steroid-only group. There were no deaths, and no emergencies that required insertion of a breathing tube.
The study results appear in the New England Journal of Medicine.
The past safety concerns might have cropped up because patients were using an LABA without also taking a steroid alongside it, Szefler said. LABAs provide only short-term relief, and do nothing to treat the chronic airway inflammation targeted by steroids.
"In asthma, when you're using the long-acting beta agonist it should be combined with a steroid," he said.
Inhaled steroids will remain the front-line option for kids with chronic asthma, but this trial shows the combination drug is "a tool that can be used for those children that require something in addition to steroids for their persistent asthma," said Dr Marilyn Li. She is an assistant professor of clinical paediatrics at the University of Southern California's Keck School of Medicine.
"There's been widespread fear about that kind of medication because of the long-acting beta agonist component, and unjustly so because, truthfully, for those children who have moderate to severe asthma, there is a serious unmet need," Li said.