For such patients, Spiriva works at least as well as Serevent -- although more work is needed to see whether Spiriva is safe and remains effective in long-term use.
Spiriva "might provide an alternative to other asthma treatments, expanding options available to patients for controlling their asthma," Susan B. Shurin, MD, acting director of the National Heart, Lung, and Blood Institute said in a news release.
The findings come from a study paid for by the National Institutes of Health and conducted at 11 U.S. asthma research centers.
Spiriva was donated by manufacturer Boehringer Ingelheim. But according to the editors of the New England Journal of Medicine, GlaxoSmithKline refused to donate Serevent to the head-to-head study. This forced taxpayers to foot the $900,000 bill for buying and repackaging the drug and creating an identical-looking placebo.
Spiriva is an anticholinergic drug -- that is, it relaxes smooth muscles in the lung by a different mechanism than long-acting beta-agonists such as Serevent. It's approved for treatment of COPD (chronic obstructive pulmonary disease), but not for asthma.
Currently, when patients can't keep their asthma under control with steroid inhalers alone, doctors have several options. The most popular options are to double the steroid inhaler dose, or to add Serevent or a similar medication.
Might Spiriva work at least as well? To find out, Wake Forest researcher Stephen P. Peters, MD, PhD, and colleagues enrolled 210 people with poorly controlled asthma in their study. Each patient got 14 weeks of each treatment: double-dose of steroid inhaler, Spiriva plus steroid inhaler, and Serevent plus steroid inhaler.
Spiriva was much more effective than doubling the steroid inhaler dose -- and it was just as effective as Serevent.
Spiriva for Asthma: Long-Term Safety Untested
However, 14 weeks is not a long time in the life of a person with asthma. Ongoing safety studies are exploring whether Spiriva is safe as a long-term treatment for asthma not controlled by steroid inhalers.
"Careful assessment of [Spiriva] risk in this population of patients will be needed," warns Northwestern University asthma expert Lewis J. Smith, MD, in an editorial accompanying the Peters Sept. 19 online report in the New England Journal of Medicine.
In 2007, Boehringer Ingelheim informed the FDA that there might be a higher risk of stroke in patients taking Spiriva. An analysis of clinical trial data suggested this might be true, and in 2008 the FDA sent out a warning that it was investigating the drug's safety. But later that year, a larger study found no increased risk of stroke, heart disease, or death in patients on Spiriva -- and in 2009, an FDA advisory panel accepted this conclusion.
Meanwhile, increasing concern that Serevent and similar drugs cause rare but serious asthma flare-ups has led the FDA to advise patients to use the drugs as little as possible.