Omeprazole Meprasil 20mg is indicated for the treatment of gastroesophageal reflux disease (GERD) and peptic ulcers, contraindicated in patients with known hypersensitivity to omeprazole or any component of the formulation, may cause side effects such as headache, nausea, and gastrointestinal disturbances, and can interact with drugs like clopidogrel and certain antifungals or anticoagulants, potentially altering their effectiveness.