Doubling the dose of inhaled steroids doesn't appear to dampen asthma attacks, despite the practice being recommended by many doctors, Canadian researchers said Thursday.
More than seven percent of adult Americans, and even more kids, have asthma, causing millions of visits to emergency rooms and doctors' offices every year.
Until recently, national guidelines advised people to double the dose of inhaled steroids when they felt the telltale signs of an asthma flare-up coming on, such as chest tightness and coughing.
Those steroid medications, such as Pulmicort or Flovent, keep airway inflammation under control on a daily basis in asthmatics. So doctors had reasoned higher doses might work in emergencies.
"It is a reasonable thing to try," said Dr. Andy Nish, an asthma expert at the Allergy and Asthma Care Center in Gainesville, Georgia, who was not involved in the new study, published by The Cochrane Collaboration.
"This article shows that sometimes we do things that seem reasonable and yet maybe aren't as effective as we would like to think."
The Canadian researchers pooled the best data available on outcomes with the higher doses, including five clinical trials that assigned 1,250 patients randomly to take either the standard dose of inhaled steroids or an increased dose.
Overall, doubling or even quadrupling the amount of inhalant at the onset of a flare-up didn't make patients any less likely to need rescue treatment with swallowed or injected steroids such as prednisone.
While effective, those stronger treatments may cause serious side effects like depression or bone thinning, so patients and doctors prefer to limit their use.
Except for 28 patients, all study participants were adults, so the findings may not apply to children.
"The most important strategy to reduce the rate and severity of flare-ups is to take daily preventive medications for asthma," Dr. Francine M. Ducharme, who worked on the study, said in an e-mail to Reuters Health.
Ducharme, of the University of Montreal, said it was still common for doctors to recommend high-dose inhaled steroids to stave off attacks.
Instead, she said, patients should try rescue inhalers, which contain short-acting drugs such as albuterol that open up the airways. If that doesn't work, swallowed or injected steroids may be necessary.
Nish said the best thing to do is try to prevent flare-ups. "Avoid cigarette smoke, stay indoors if it is a high-smog day, avoid exertion if it's a cold or a hot day, and get your flu shot."
And with the right medication, he said, many asthma attacks can be prevented.
"We can't keep you from getting a cold, but hopefully we can keep that cold from causing significant exacerbations in your asthma," he said.