Promethazine is a drug commonly used to relieve the symptoms of allergies, colds, and other illnesses. The drug is a type of antihistamine that helps relieve symptoms such as itching, sneezing, runny nose, and watery eyes. There are several other synonyms for promethazine, including Phenergan, Prothiazine, Avomine, and Fargan. While all of these drugs have similar uses and effects, they may differ in terms of their side effects or potency. It is always important to talk to your doctor or pharmacist before taking any new medication to ensure that it is safe and effective for your specific needs.