I JUST NEEDED TO KNOW THE MECHANISM OF ACTION FOR EACH DRUG AS PART OF A SCHOOL PROJECT PLEASE HELP ME OUT AS MUCH AS YOU CAN, I AHVE GONE TO SEVERAL WEB SITES AND NONE OF THEM TELL ME THE MECHANISM OF ACTION 1 DEXTROMETHORPHAN HYDROBROMIDE 2. GUAIFENESIN 3. ACETAMINOPHEN
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