Hi 5 Tablet is used to treat peptic ulcers, duodenal ulcers, gastro-oesophageal reflux disease (reflux of gastric contents into the oesophagus) and dyspepsia. It contains Ilaprazole, which reduces the amount of acid produced, heals the ulcers and prevents the formation of new ulcers. Thus, it prevents symptoms of hyperacidity which includes heartburn and indigestion. In some cases, you may experience common side effects such as headache, dizziness, diarrhoea, constipation, nausea, vomiting, flatulence (wind), weakness, flu-like symptoms, back pain, aches, infection, difficulty sleeping, cough, sore throat and runny nose. Before taking this medicine, you should tell your doctor if you are allergic to any of its components or if you are pregnant/breastfeeding, and about all the medications you are taking and pre-existing medical conditions.