Key takeaways
Prochlorperazine and promethazine (Phenergan) are both used to treat nausea and vomiting, but they have different primary uses and mechanisms. Prochlorperazine also treats schizophrenia and generalized anxiety disorder by blocking dopamine in the brain. It is typically taken 3 to 4 times daily and can cause side effects like drowsiness, dizziness, and blurry vision. Promethazine, on the other hand, is also useful for treating allergy symptoms, motion sickness, and can be used as a sedative before surgery. It’s available in various forms, including tablets, oral solution, rectal suppository, and injection. It starts working within 20 minutes, compared to prochlorperazine which starts working in 30 minutes. Promethazine can cause drowsiness and has a higher risk of breathing problems in children under 2 years old. Both medications are available as low-cost generics.
