PAN 40 Tablet is used to treat gastroesophageal reflux disease (GERD), stomach ulcer, Zollinger Ellison syndrome (overproduction of acid due to pancreatic tumour), duodenal ulcer, gastric ulcer and Crohn's Disease-associated Ulcers. It contains Pantoprazole, which reduces the amount of acid your stomach makes. It prevents the release of stomach acid and relieves symptoms of food pipe lining inflammation (esophagitis), gastroesophageal reflux disease (GERD), or heartburn. It may cause common side effects like headache, diarrhoea, nausea, abdominal pain, vomiting, flatulence, dizziness, and arthralgia (joint pain). 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.