The H2 blockers (also called H2 antagonists) were the first effective drugs for peptic ulcer. In the 1980s, they were the backbone of treatment for ulcers and gastroesophageal reflux disease (GERD). Now, antibiotics cure non-NSAID ulcers, and proton pump inhibitors (PPIs) are better for GERD. Therefore, H2 antagonists face an uncertain future as prescription drugs. Nonetheless, they are comparatively cheap, effective, and very safe for heartburn relief. Lower dose preparations are available over-the-counter. Reviewed and updated 2009.