Over-the-counter (OTC) drugs are medicines you can buy without a doctor's prescription. OTC cough medicines are grouped into two types: antitussives and expectorants.

Antitussives are cough suppressants. They relieve your cough by blocking the cough reflex. Dextromethorphan is a commonly used antitussive.

Expectorants thin mucus. This may make coughing work better to clear the mucus from the airway. The only expectorant available in OTC products is guaifenesin

Dextromethorphan and are meant to treat many symptoms at once. However, if your main symptom is cough, be careful of the drying effect of antihistamines and decongestants in combination medicines. This effect can make mucus thicker and harder to clear from the airways, which can make a cough worse. They also increase or risk for medication interactions. Be sure not to "double up" on cough medicine. Many OTC cold and allergy products contain cough medicine, as do some prescription drugs.

Information provided by Carin Bejarno of Grimes Family Physicians.

Article courtesy of Grimes Living magazine.