Cough Medicine: Should You or Shouldn’t You?

Do cough medicines work? Given the billions of dollars that we spend on over-the-counter cough and cold remedies in the U.S. every year, we clearly think they do. But cough experts are not so sure.

“We want to believe these remedies will work because we’re so desperately uncomfortable when we’re sick,” says John E. Heffner, MD, a pulmonologist and immediate past president of the American Thoracic Society.  “But clinical trials have not found that cough medicines are any better than a placebo.”

Among experts, doubts about the effectiveness of cough medicines are longstanding. Members of the Consumer Healthcare Products Association ( CHPA), an association that represents most of the makers of nonprescription OTC cough and cold medicines in children, voluntarily modified the labels of OTC cough and cold medicines to state "do not use" in children under 4 years of age.

The reasons: a lack of proven benefit and a small risk of serious side effects.

While cough medicines don’t pose the same risks in adults, a larger question looms.  If there’s no good evidence that these drugs work, should anyone be using them? Should we banish those sugary cough syrups from our medicine cabinets? Is it time for us to muddle through the common cold without them?

Cough Medicine: The Evidence

Over the years, a number of studies have found little evidence that cough medicines work. 

• Most recently, in 2006, the American College of Chest Physicians (ACCP) surveyed a number of cough medicine studies from the last few decades.  These medicines include drugs to suppress the cough, like dextromethorphan (DM), as well as expectorants like guaifenesin, which are supposed to loosen up mucus in the airways so you can cough it up. The AACP found no evidence that these medicines help people with run-of-the-mill coughs caused by viruses.  
• A 2004 review of studies had a similar conclusion.  That study found that almost 60% of the studies showed no benefit to cough medicines over a placebo.

Of course, it’s important to understand that these studies have not proven that cough medicines don’t work.  Rather, they’ve just shown that there isn’t good evidence that they do.  It’s possible that further studies could show that they help.

The ACCP study did find one combination of drugs that did work.  When combined with a decongestant, the older antihistamine, brompheniramine, eased coughs caused by colds and allergies.

The catch is that brompheniramine, like other first generation antihistamines, is a sedative.  So it’s not something you could take before school or work.  “The sedative effect is actually what might be helping with the cough,” says Norman Edelman, MD, chief medical officer at the American Lung Association.