Cytotec, also known as misoprostol, is a medication that’s mainly used to prevent stomach ulcers while a patient is taking nonsteroidal anti-inflammatory drugs (NSAIDs). The goal is to reduce stomach acid in order to protect the stomach lining, therefore preventing gastric ulcers and possible bleeding. Common Cytotec adverse reactions can include abdominal pain, nausea, vomiting, and diarrhea.