For coughs, syrups may not be a panacea

CHICAGO -- Despite the billions of dollars spent every year in this country on over-the-counter cough syrups, most such medicines do little if anything to relieve coughs, chest physicians say.

Over-the-counter cough syrups generally contain drugs in doses too low to be effective or have combinations of drugs that have not been proven to treat coughs, said Dr. Richard Irwin, chairman of a cough guidelines committee for the American College of Chest Physicians.

Store shelves are crowded with cough syrups promising speedy, relief without a prescription, and without causing drowsiness.

''The best studies that we have to date would suggest there's not a lot of justification for using these medications because they haven't been shown to work," said Irwin, a professor of medicine at the University of Massachusetts Medical School in Worcester.

The group's guidelines discourage use of over-the-counter cough medicines. Irwin said that not only are such medicines ineffective at treating coughs, they can also can lead patients to delay seeking treatment for more serious conditions, including whooping cough.

The guidelines strongly recommend that adults receive a new adult vaccine for whooping cough. The vaccine was approved last year. The Consumer Healthcare Products Association, a trade group for makers of over-the-counter medications, disputed the guidelines and said that over-the-counter cough medicines provide relief to millions each year.

The guidelines were published in the January issue of Chest, the American College of Chest Physicians' journal, released yesterday. The recommendations have been endorsed by the college, the American Thoracic Society, and the Canadian Thoracic Society.

Many over-the-counter cough medicines advertise that they don't cause drowsiness, but Irwin said that is because they do not contain older antihistamine drugs that do help relieve coughs that are due to colds.

These antihistamines, including diphenhydramine -- an active ingredient in Benadryl -- are also available over the counter but are not marketed as cough medicines, Irwin said. Some syrups contain two drugs that have been shown to help relieve coughs -- codeine and dextromethorphan -- but generally the doses are too small to be effective, Irwin said.