Key takeaways
Promethazine (Phenergan) and Promethazine DM (promethazine/dextromethorphan) are both medications that can be use to treat symptoms related to allergies. Promethazine is an antihistamine that is also used for nausea, vomiting, and motion sickness, while Promethazine DM combines promethazine with dextromethorphan, a cough suppressant, to relieve cough and cold symptoms. Promethazine is available in various forms, including tablets, oral solutions, rectal suppositories, and injections, whereas Promethazine DM is only available as an oral syrup. Both medications should not be used in children under 2 years old due to the risk of serious breathing problems. Promethazine can cause side effects like drowsiness and dizziness, and it interacts with alcohol and certain medications like MAOIs. Promethazine DM has similar side effects and interactions but also includes dextromethorphan, which has the potential for overdose if combined with other cough medications. While both medications can make you sleepy, Promethazine DM is specifically used for short-term relief of cough and cold symptoms, making it different from the broader uses of Promethazine.
