(The Atlanta Journal-Constitution) -- Several common medications used by thousands to treat respiratory diseases are dangerous, may be causing four out of five asthma-related deaths a year in the United States and should be taken off the market, two prominent researchers have recommended.

Dr. Edwin Salpeter, professor emeritus at Cornell University, and his daughter, Dr. Shelley Salpeter, a professor at Stanford University, analyzed and combined the results of 19 published studies performed from 1966 to 2005 involving 33,826 patients who used the inhalers.

They found the drugs salmeterol, found in Serevent and Advair, both made by GlaxoSmithKline, and formoterol found in Foradil, made by Novartis, and the generic albuterol can increase the risk of hospitalizations and respiratory death.

The drugs are prescribed for treatment of asthma and chronic obstructive pulmonary disease, such as emphysema. The drugs are "long-acting beta-agonists," that relax constricted airways.

Pharmaceutical firms GlaxoSmithKline and Novartis dismissed the study, published in a recent issue of the Annals of Internal Medicine, as wrong.

Mary Anne Rhyne, a spokeswoman for Glaxo, said the Salpeters' conclusions were based on old data, and that the Food and Drug Administration recently ruled that the benefits of the drugs outweighed any risk.

She said asthma deaths have decreased by 31 percent since the introduction of beta-agonists.

The Salpeters said the medications they studied relieve asthma symptoms but also promote bronchial inflammation and sensitivity without warning. Dr. Shelley Salpeter said "that approximately 4,000 out of the 5,000 asthma deaths that occur in the U.S. each year are actually caused by these long-acting beta-agonists, and we urge that these agents be taken off the market."

"The use of long-acting beta-agonists [bronchodilators] could be associated with a clinically significant number of unnecessary hospitalizations, intensive care unit admissions and deaths each year," the authors wrote.

Long-acting beta-agonists have been controversial for years. The FDA requires stronger wording on the drug labels cautioning that beta-agonists "may make asthma episodes more severe when they occur."

Among bega-agonists is the widely prescribed Advair, which is a combination of two drugs: Flovent, generically called fulticasone, and Serevent. Advair is now the fourth best selling drug in the world, with $5.6 billion in annual sales. According to published reports, more than 68 million prescriptions for Advair have been written in the U.S. since its introduction in 2001.

Dr. David Tanner of the Atlanta Allergy and Asthma clinics strongly disagreed with the Salpeters' conclusions: "They tend to damn the whole class of drugs, beta-agonists, and in my opinion, it's many times the way the drug is used by the patient" that affects outcome.

Dr. Jerry Teague of Emory University's Medical School wasn't happy with the Salpeters' study, either. He said beta-agonist drugs help people.

Copyright 2006 The Atlanta Journal-Constitution