Do not take this medicine with any of the following medications:
-MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate
-procarbazine

This medicine may also interact with the following medications:
-other medicines for colds or allergy
-medicines for depression or other mental disturbances

They need to know if you have any of these conditions:
-chronic bronchitis
-kidney disease
-liver disease
-lung or breathing disease, like asthma or emphysema
-unable to sit up
-an unusual or allergic reaction to dextromethorphan, guaifenesin, other medicines, foods, dyes, bromides, or preservatives
-pregnant or trying to get pregnant
-breast-feeding

Do not treat yourself for a cough for more than 1 week without consulting your doctor or health care professional. If you have a high fever, skin rash, lasting headache, or sore throat, see your doctor.

Drink 6 to 8 glasses of water daily while you are taking this medicine to help loosen mucus.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.

Keep out of the reach of children.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Keep bottle tightly closed. Throw away any unused medicine after the expiration date.