"There is no clinical evidence that over-the-counter cough expectorants or suppressants actually relieve cough," says panel chairman and pulmonary specialist Richard D. Irwin, MD.
The updated cough treatment guidelines were issued by the American College of Chest Physicians and are published in the January issue of its journal Chest. They are endorsed by the American Thoracic Society and the Canadian Thoracic Society.
Nondrowsy No Good
So what should you do instead to relieve that irritating cough?
The panel recommends the use of older antihistamines with a decongestant for the treatment of coughs due to colds, allergies, and sinuses in adults. They specifically suggest the antihistamine brompheniramine and the decongestant pseudoephedrine, both found in many over-the-counter cold remedies.
Newer antihistamines, which are nonsedating, are not effective for treating coughs, Irwin tells WebMD.
"If you take an [antihistamine] medication that says 'nonsedating' or 'nondrowsy' on the label, it isn't going to do anything for your cough," he says.
Each year in the United States, roughly 30 million Americans see their doctors because of coughs.
"Cough is the No. 1 reason why patients seek medical attention," Irwin says. "Although an occasional cough is normal, excessive coughing or coughing that produces blood or thick, discolored mucus is abnormal."
ACCP President W. Michael Alberts, MD, tells WebMD the guidelines were updated to reflect new research on the treatment of coughs.
Kids and Cough Medicine
While the revised ACCP guidelines stop short of saying that adults should not take over-the-counter cough medications, this was the group's recommendation for children under the age of 15.
"Cough and cold medicines are not useful in children and can actually be harmful," says Irwin, who is chief of the division of pulmonary, allergy, and critical care medicine at the University of Massachusetts Medical School.
"In most cases, a cough that is unrelated to chronic lung conditions, environmental influences, or other specific factors, will resolve on its own."
But pediatric lung specialist William Brendle Glomb, MD, who helped write the new guidelines, tells WebMD that he frequently treats children with products such as Robitussin and will continue to do so.
"I have discussed this with every pediatric pulmonologist that I know, and we all use it," he says. "It works wonderfully to clear the mucus out."
The problem, he says, is that there have been very few studies done on over-the-counter cough medicines, and most were conducted decades ago. Most studies also involved narcotic products containing codeine.
"There are big holes in the scientific literature, and this is one of them," he says. "These products just haven't been studied."
Though he disagrees with some of the wording in the new guidelines, Glomb does agree that coughs in children should not necessarily be treated.
"When children cough it is generally because they need to get out whatever it is that is in there," he says.
Whooping Cough Shot for Adults
The revised guidelines represent the most comprehensive recommendations for the diagnosis and management of cough in adults and children ever published.
"People may think they have to put up with coughs, but they don't," Alberts says. "Coughing is a symptom that something is wrong, but it can be effectively treated with proper medical attention."
Known medically as pertussis, whooping cough is a highly contagious respiratory infection characterized by coughing so violent that it can lead to choking, vomiting, passing out, and even broken ribs.
Children are routinely vaccinated against the disease, but older versions of the vaccine were too dangerous for use in adults because they could potentially cause serious central nervous system side effects.
Last year, however, the FDA approved a new version of the vaccine that testing has shown to be both safe and effective for use by children over the age of 10 and adults under the age of 65.
The revised guidelines call for adults aged 64 and under to get the booster pertussis, tetanus, and diphtheria vaccine every 10 years.
The hope, Irwin says, is that whooping cough can be eradicated in the same way that polio was several generations ago.
"Whooping cough is thought of as a kid's disease, but 28% of cases occur in adults," Irwin says. "A study in my state of Massachusetts showed that 40% of coughs severe enough to send patients to the ER were caused by pertussis."