THURSDAY, June 12 (HealthDay News) -- In people suffering from chronic obstructive pulmonary disease (COPD), the expectorant carbocisteine seems to help slow worsening of symptoms, Chinese researchers report.

COPD is a progressive, destructive disease of the lungs, usually brought on by smoking, for which there's no known cure. Symptoms include restricted breathing, secretion of mucus, oxidative stress and inflammation of the airway.

"COPD is a major respiratory disease that affects many people, especially the elderly, and the treatment of COPD is costly," said lead researcher Dr. Jin-Ping Zheng, of the Guangzhou Institute of Respiratory Disease in Guangzhou, China.

"Carbocisteine is a highly cost-effective medicine that prevents exacerbation of COPD," Zheng said.

Long-term use of carbocisteine can help preserve health-care resourses, Zheng said. "This is especially good for developing countries and low-income populations -- it provides an option to treat COPD," he said. "Carbocisteine, as well as other mucolytics, are old medicines. However, carefully conducted clinical trials of existing medications can offer new insights into COPD care."

The findings are in the June 15 issue of The Lancet.

For the study, 709 patients with COPD were randomly selected to receive daily doses of carbocisteine or placebo. Over the year of the study, patients receiving carbocisteine had a 25 percent reduction in the number of exacerbations of COPD, compared with patients receiving a placebo, the researchers found.

"In addition, quality of life was improved significantly," Zheng said, adding that long-term administration of mucolytics, such as carbocisteine, should be recognized as a worthwhile treatment for COPD.

Dr. Paul Scanlon, of the Mayo Clinic's Division of Pulmonary and Critical Care Medicine, said using a similar medication might be effective and less expensive than current COPD treatments in the United States.

"Results of the study are impressive and fairly convincing," said Scanlon. "The magnitude of reduction of the frequency of exacerbations of 25 percent is on a par with other drugs that we have, such as inhaled corticosteroids and long-acting beta agonists."

The question is, what would be the role of this drug in clinical practice in the United States, Scanlon said. He noted that drugs used in China and other parts of the world to treat COPD are different from the drugs used in United States.

"The drug works," Scanlon said. "But it has a role yet to be defined. If it has treatment effects on a par with inhaled corticosteroids and long-acting beta agonists, which are much more expensive, then carbocisteine has a role in developing countries and may have a role here," he said.

Dr. Neil Schachter, a professor of pulmonary medicine at Mount Sinai Medical Center in New York City, said it's not known whether carbocisteine could be used instead of other drugs. "Some of these drugs work additively when given together, so it might be even more effective in conjunction with some of the current therapies," he said. "However, whether it fills the roles that other drugs such as steroids or long-acting beta agonists fill is not clear."

More information

To learn more about COPD, visit the U.S. National Heart, Lung, and Blood Institute.