Ondion 4mg Tablet MD is an antiemetic medicine commonly used to control nausea and vomiting due to certain medical conditions like stomach upset. It is also used to prevent nausea and vomiting caused due to surgery, cancer drug therapy, or radiotherapy. Your doctor will suggest the appropriate dose depending on what you are taking it for. The most common side effects include headache, diarrhoea, or constipation and feeling tired. These symptoms should disappear when you stop taking the medicine. Before taking this medicine, tell your doctor if you have heart or liver problems or a blockage in your stomach or intestines.