Pfizer's Spiriva enhances asthma treatment
Adding Spiriva to conventional therapy improves symptoms in patients whose asthma is poorly controlled and gives them more days without breathing problems, researchers reported on Sunday.
Spiriva, co-marketed by Pfizer and the privately held Boehringer Ingelheim, is already used for chronic obstructive pulmonary disease and works by blocking the nerves that can tighten the muscles surrounding the airways to the lungs.
Some asthma patients need more than the low dose of the corticosteroids they are typically given to inhale, but doctors fear more aggressive treatment can have drawbacks, including making the asthma worse.
Seeking a better treatment, the researchers tested different regimens on 210 patients, all of whom continued inhaling a low dose of corticosteroids.
For 14 weeks they received a double dose of the steroid, during another 14-week stretch they added Spiriva, known generically as tiotropium, and for a third testing period they inhaled salmeterol, a drug known as a beta agonist that relaxes the muscles lining the breathing passages of the lungs.
Spiriva worked at least as well as salmeterol and better than doubling the steroid dose, according to the results, released online by the New England Journal of Medicine and at a meeting of the European Respiratory Society in Barcelona, Spain.
Patients who got Spiriva had improved symptoms and a greater ability to force air from their lungs.
The researchers estimated that long-term treatment would give the patients an extra 48 days a year without breathing problems, compared to 19 days if the steroid dose were simply doubled.
"Tiotropium relaxes smooth muscle in the airways through a different mechanism than beta agonists, and thus may help people who do not respond well to current recommended treatments," Dr. Stephen Peters of Wake Forest University Baptist Medical Center in Winston-Salem, North Carolina, who worked on the study, said in a statement.
But it did not work for everyone. Nine patients had their asthma get worse while on Spiriva, compared to five while they were receiving salmeterol and 16 when they got a double dose of corticosteroid.
In a commentary, Dr. Lewis Smith of Northwestern University in Chicago said some doctors are already using Spiriva instead of other secondary drugs when steroids do not provide enough relief, but more research is needed to see whether it can reduce potentially life-threatening episodes of asthma over the long term.
"This study's results show that tiotropium bromide might provide an alternative to other asthma treatments, expanding options available to patients for controlling their asthma," Dr. Susan Shurin, acting director of the National Heart, Lung and Blood Institute, which funded the study, said in a statement.
"The goal in managing asthma is to prevent symptoms so patients can pursue activities to the fullest."