GENERIC NAME(S): Promethazine Its other effects (such as anti-nausea, calming, pain relief) may work by affecting other natural substances (such as. Learn about Phenergan (Promethazine) may treat, uses, dosage, side effects, drug Generic Name: promethazine; Brand Name: Phenergan Therapy adjunctive to meperidine or other analgesics for control of postoperative pain. Sedation. Dec 23, Generic Name: promethazine (oral) (pro METH a zeen) includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Subscribe to Drugs. Promerhazine all directions on promethazind prescription label. Be careful if you see more or do anything that requires you to be alert. This includes vitamins, otner, herbal products, othre drugs prescribed by other doctors. Explore now. Nmae should not be given to a child younger than 2 years old. If a child is using this medicine, tell your doctor if the child has any changes in weight. Promethazine may cause breathing to slow or stop, and may cause death in children. Talk to your doctor if you think you might be pregnant while you are taking promethazine. Do not take this medicine in larger or smaller amounts or for longer than recommended. This list is not complete and there are many other medicines that can interact with Phenergan. Weekly news roundup. Keep a list with you of all the medicines you use and show this list to any doctor or other healthcare provider who treats you. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. Be careful if you drive or do anything that requires you to be alert. Promethazine side effects in more detail. If you do not have a dose-measuring device, ask your pharmacist for one. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. It is not known whether promethazine will harm an unborn baby.