Cystic fibrosis is a genetic disease that affects a number of organs in the body - especially the lungs and pancreas - by clogging them with thick, sticky mucus.

The new medication is called denufosol and acts to help prevent the formation of the mucus.

Doctors say the drug can be given early in the progression of the condition and may delay the disease getting worse.

The medication works by normalising the surface of the airways.

In patients with cystic fibrosis, mucus builds up in the patient's airways causing obstruction and respiratory infections.

Dr Frank Accurso, professor of paediatrics at the University of Colorado School of Medicine in Denver, says the new drug helps enhance the hydration of the airways and can aid in clearing mucus.

"The drug is different from other cystic fibrosis medications which primarily treat the symptoms rather than the underlying causes," he said.

Researchers enrolled 352 cystic fibrosis patients and they were given either the new drug three times daily for 24 weeks or a placebo.

At the start of the study most patients had mild impairment of their lung function.

Patients' lung functions were measured and they found those who received the active drug had better exhalation rates than the placebo group.

Both groups had a similar number of adverse events and the active drug group had fewer headaches and sinus problems.