Chicago ? The nation’s chest doctors are now saying what you might have already known: outside Robitussin, over-the-counter cough syrup doesn’t really do much.

The American College of Chest Physicians issued new guidelines discouraging use of the medicines.

The group says nonprescription cough syrups generally contain drugs in too low a dose to be effective, or contain combinations of drugs that have never been proven to treat coughs.

The exceptions: codeine and dextromethorphan. The latter is in Robitussin.