Where can I find Donnagel? I had awful nausea and this is the only thing we found that works. Im on zofran and it doesn't help. ## Hello, Clara! How are you? I'm sorry, but Donnagel PG has been discontinued by the manufacturer. Have you ever tried Phenergan? It contains the active ingredient Promethazine, it's an antihistamine that's used to prevent nausea and vomiting. The FDA lists its typical side effects as possibly including dizziness, drowsiness and dry mouth.