What Is Promethazine and Codeine 6.25mg/473ml? Promethazine and Codeine syrup combines two active ingredients: promethazine, an antihistamine that relieves allergy symptoms and nausea, and codeine, an opioid used as a cough suppressant and mild pain reliever. The concentration 6.25mg/473ml refers to the amount of codeine per volume of syrup. This medicine is prescribed for temporary […]