Known brand names include Prilosec.
A proton pump inhibitor that sharply lowers stomach acid. It treats GERD and erosive esophagitis, heals duodenal and gastric ulcers, helps clear H. pylori with antibiotics, and controls rare acid-overproducing conditions such as Zollinger-Ellison syndrome.
Omeprazole blocks the proton pump, an enzyme on the acid-making cells of the stomach lining. This pump is the last step in making acid, so blocking it cuts acid output no matter what is triggering it. The capsules hold coated granules so stomach acid does not break the drug down, and it is absorbed only after it leaves the stomach. With less acid, irritated or damaged tissue in the esophagus, stomach, and intestine can heal.
It starts reducing acid within an hour of a dose, has its peak effect within two hours, and a single dose can keep working for up to 72 hours even though the drug stays in the blood only briefly. Its effect builds with daily doses and levels off after a few days, and acid making slowly returns over several days after stopping. The body answers lower acid by raising its gastrin level, which can make some cells in the stomach lining multiply over time.
Omeprazole is a capsule that lowers stomach acid. It treats heartburn and other symptoms of gastroesophageal reflux disease (GERD), in which acid flows backward from the stomach into the esophagus, the tube between the throat and stomach. It heals an esophagus damaged by acid and helps keep it healed, and it heals ulcers in the stomach and in the first part of the small intestine. Along with antibiotics, it helps clear H. pylori, a type of bacteria in the stomach, to lower the chance that an intestinal ulcer comes back.
Children 2 years and older can take it for reflux and for an acid-damaged esophagus, while the ulcer and H. pylori uses are for adults only. In adults it also treats rare conditions such as Zollinger-Ellison syndrome, in which the stomach makes far too much acid, over the long term. For ulcers and a damaged esophagus, it is usually given as a short course of several weeks. The capsules are taken by mouth, usually before a meal, and kept up even when the person feels well.
Headache, stomach pain, nausea, diarrhea, vomiting, gas, constipation, dizziness, and rash are the common complaints. The label treats a serious gut infection called C. difficile as a risk, especially in the hospital, along with kidney inflammation. With high doses or long-term use, it warns about broken bones, low magnesium, low vitamin B12, and growths in the stomach lining, and it also warns about severe skin reactions and lupus.