Chocolate could be key to curing persistent cough

If the trials are successful, the drug could be on the market within two years. Millions worldwide suffer from a persistent cough, one that lasts for more than two weeks.
Some have asthma-like symptoms while others suffer from heartburn, reports the Daily Mail.
But most widely available cough products soothe the symptoms rather than deal with the cause, and have been criticised for side effects such as drowsiness.

There are safety concerns about side effects from other products that are codeine-based, which use a chemical called an opioid.

Previous research by London's National Heart and Lung Institute found that theobromine is 33 percent more effective than codeine at stopping coughing. It works directly on the vagus nerve, which is responsible for persistent coughing.

Research in South Korea has shown that theobromine has none of the side effects associated with standard drug treatments for persistent cough.

Professor Alyn Morice, who heads the Hull Cough Clinic, said: "Due to the drawbacks of current opioid drugs such as codeine, we are in desperate need of a non-opioid treatment with a drastically improved side effect profile for patients."