Nexium 40 mg is a prescription medication containing esomeprazole, available in a pack of 14 tablets. It belongs to a class of drugs known as proton pump inhibitors (PPIs) used to reduce stomach acid production. This medication is manufactured by AstraZeneca. As this is a prescription medication, it should only be taken under the direction and supervision of a healthcare provider. The dosage, duration of treatment, and specific usage instructions should be determined by your doctor based on your medical condition.