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Cough suppressant
Dry cough, hacking, wheezing

What the drug does:
Suppresses the body's cough reflex. This is only recommended for times when you can't sleep or your cough is causing pain. Combination cough expectorant-suppressants are not recommended.

Active ingredients:
Codeine, available by prescription, is effective but has powerful sedative effects. Dextromethorphan is the synthetic over-the-counter relative—minus the sedating and often constipating side effects.

Who should avoid:
Pregnant or nursing women; anyone with a wet cough or a cough due to asthma, emphysema, bronchitis or smoking; those using MAOIs. Do not mix codeine with alcohol or tranquilizers or take when driving.