Prevacid (generic: lansoprazole) is both an over-the-counter and a prescription medication. The over-the-counter form is used to treat heartburn. The prescription form is used to treat ulcers, GERD, erosive esophagitis, and other conditions. This medication page refers to the prescription form of Prevacid.

Prevacid belongs to a group of drugs called proton pump inhibitors, which work by reducing the amount of acid in the stomach.

This medication comes in capsule form and in a tablet that dissolves on the tongue (Prevacid SoluTab). Prevacid is taken once a day, before eating.

Common side effects of Prevacid include diarrhea, stomach pain, and nausea.