Drug Uses Compazine is used for controlling severe nausea and vomiting and treating schizophrenia. It is also used for the short-term (4 weeks) treatment of generalized nonpsychotic anxiety. It may also be used for other conditions as determined by your doctor. How to use Use Compazine as directed by your doctor. Check the label on the medicine for exact dosing instructions. Take Compazine by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation. Drug Class and Mechanism Compazine is a phenothiazine. It works by blocking a certain chemical (dopamine) in the brain. Missed Dose If you miss a dose of Compazine, skip the missed dose. Go back to your regular dosing schedule. Do not take 2 doses at once. Storage Store Compazine at 77 degrees F (25 degrees C). Brief storage between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Compazine out of the reach of children and away from pets.