you have to be careful when mixing over-the-counter cold medicines. as a pharmacist i tend to tell my patients to avoid products that treat multiple symptoms and contain several ingredients. when you use these products you often end up taking something for a symptom you do not have. also you may end up taking too much of one type of ingredient if you mix products. i do not know what cold medicine you took or if that medicine contained a cough suppressant. therefore i could not tell you if it was ok to use dextromethorphan with it. i suggest you take the products to a pharmacist who can review them with you to make sure you do not overdo it.
is it safe to take over-the-counter cold medicine for multiple symptoms along with dextromethorphan for a severe cough?