Antacid and Reflux Drugs: H2 Blockers
- Cimetidine (Tagamet, Tagamet HB)
- Famotidine (Pepcid, Pepcid AC)
- Nizatidine (Axid)
- Ranitidine (Zantac)
HOW DO THESE DRUGS WORK?
This group of acid-blocking medications works by blocking the receptors for histamine receptors in the stomach wall. Histamine is a chemical that stimulates the acid-producing cells of the stomach. These drugs are also known as histamine antagonists because they block the histamine type 2 receptor. They are best taken 30 minutes before meals and at nighttime before bed to prevent heartburn. These medications are available in lower doses over the counter or at higher doses by prescription only.
WHAT ARE THE BENEFITS?
H2 blockers are effective for relieving the symptoms of GERD, especially heartburn. They are easily accessible over the counter. They are not effective in the prevention or treatment of inflammation and erosion of the esophagus (esophagitis) that can occur with GERD.
POTENTIAL SIDE EFFECTS
Side effects may include constipation, diarrhea, fatigue, headache, insomnia, muscle pain, nausea, and vomiting. Other side effects include irregular heartbeat, impotence, rash, visual changes, allergic reactions, and hepatitis. Side effects due to cimetidine are rare and generally are reversible once the medication is stopped.Minor side effects include constipation, diarrhea, fatigue, headache, insomnia, muscle pain, nausea, and vomiting. Major side effects include confusion and hallucinations (usually in elderly or critically ill patients); enlargement of the breasts; impotence (usually seen in patients on high doses for prolonged periods); decreased white blood cell counts. Other side effects include irregular heartbeat, rash, visual changes, allergic reactions, and hepatitis.
MAJOR CAUTIONS
A study in the Journal of the American Geriatrics Society found that long-term use of H2 blockers may increase the risk of mental decline in later life. Researchers looked at the use of H2 blockers among 1,558 over-65 African Americans enrolled in a study of aging. The study showed that after taking into account other factors, elderly people who reported