Dextromethorphan is a cough suppressant. It affects the signals in the brain that trigger
cough reflex.
Promethazine is an antihistamine. It blocks the effects of the naturally occurring chemical
histamine in your body.
The combination of dextromethorphan and promethazine used to treat cough, itching,
runny nose, sneezing, and itchy or watery eyes caused by colds or allergies.
Dextromethorphan will not treat a cough that is caused by smoking, asthma, or
emphysema.
Dextromethorphan and promethazine may also be used for purposes other than those
listed in this medication guide.