Doctors who treat people with asthma and acid reflux may be using a drug that doesn't help many of them.

Researchers from the Ohio State University said that the finding that as many as one-third of those studied showed no improvement makes a strong case arguing that physicians should change how they currently treat these patients.

John Mastronarde, wanted to determine if acid reflux disease, or GERD, worsens asthma symptoms. He also wanted to determine if drugs called proton pump inhibitors could help people with asthma who don't have reflux symptoms.

Up to 20 percent of asthma patients with reflux do not have heartburn symptoms, according to a news release on the work.

"We found that 'silent' GERD is likely not the cause of poorly controlled asthma, and treatment with proton pump inhibitors does not improve control or provide any benefit to the patients," said Mastronarde. "By determining which patients do not need the additional medication, we are saving them unnecessary costs, potential side effects and the risk of interactions with other drugs."

Researchers from 20 universities examined 402 adults with asthma for 24 weeks to determine if using a proton pump inhibiting drug would alleviate their asthma symptoms by preventing the release of stomach and intestinal acid.

The drug they used is formally known as esomeprazole, and it is part of the popular drugs Prilosec and Nexium.

Symptoms of asthma and GERD often overlap, making it difficult for physicians to distinguish between the two conditions, and about half of asthma patients who have reflux also have no symptoms, according to the news release. Acid reflux causes the airways in the lungs to constrict and asthmatic narrowing of the airways can induce acid reflux.