Nexium 20mg tablets contain esomeprazole and come in a pack of 14 tablets. This medication is manufactured by AstraZeneca and is used to treat certain stomach and esophageal conditions. The active ingredient in Nexium is esomeprazole 20mg. This medication belongs to a class of drugs called proton pump inhibitors (PPIs). Please consult your healthcare provider for proper usage instructions, potential side effects, and to determine if this medication is right for you.