Key takeaways
Promethazine DM (promethazine/dextromethorphan) and Promethazine with Codeine (promethazine/codeine) are both combination medications used to treat cough and upper respiratory symptoms caused by allergies or respiratory infections. They both contain promethazine, an antihistamine. However promethazine DM also contains dextromethorphan, an antitussive, while Promethazine with Codeine contains codeine, an opioid, which is why it is a controlled substance. Both medications are available as an oral liquid. Both medications are typically taken very 4 to 6 hours, but promethazine DM is not recommended for children under 2 years old whereas Promethazine with Codeine is not recommended for children under 12 years old. Common side effects of Promethazine DM include drowsiness and stomach upset, while Promethazine with Codeine can cause sleepiness, dizziness, and dry mouth. Both medications should not be taken with alcohol, but Promethazine with Codeine can cause dangerously slow breathing if mixed with alcohol or opioids.
