ranitidine, Zantac

Pharmacy Author:
Medical and Pharmacy Editor:

GENERIC NAME: ranitidine

BRAND NAME: Zantac

DRUG CLASS AND MECHANISM: Ranitidine is an oral drug that blocks the production of acid by acid-producing cells in the stomach. It belongs to a class of drugs called H2 (histamine-2) blockers that also includes cimetidine (Tagamet), nizatidine (Axid), and famotidine (Pepcid). Histamine is a naturally-occurring chemical that stimulates cells in the stomach (parietal cells) to produce acid. H2-blockers inhibit the action of histamine on the cells, thus reducing the production of acid by the stomach. Since excessive stomach acid can damage the esophagus, stomach, and duodenum and lead to inflammation and ulceration, reducing stomach acid prevents and heals acid-induced inflammation and ulcers. The FDA approved ranitidine in October 1984.

PRESCRIPTION: yes; OTC (Zantac 75 and 150 mg)

GENERIC AVAILABLE: yes

PREPARATIONS: Tablets or Capsules: 25, 75, 150 and 300 mg; Syrup: 15 mg/ml; Injection: 1 mg/ml or 25 mg/ml.

STORAGE: Tablets should be stored at room temperature between 15–30 C (59-86 F) in a tightly closed container. Syrup and injection should be stored between 4 and 25 C (39 and 77 F).

PRESCRIBED FOR: Ranitidine is useful in promoting the healing of ulcers in the stomach and duodenum, and in reducing ulcer pain. Ranitidine has been effective in preventing ulcer recurrence when given in low doses for prolonged periods of time. It also is used as needed for the treatment of occasional heartburn to  reflux of acid into the esophagus. In doses higher than that used for the treatment of ulcers, ranitidine has been helpful in treating heartburn and in healing ulcers and inflammation of the esophagus resulting from acid reflux (erosive esophagitis). It is also used for treating Zollinger Ellison syndrome, a syndrome caused by tumors that stimulate the stomach to produce large amounts of acid.

DOSING: Ranitidine may be taken with or without food.

  • Usual oral doses for treating ulcers and GERD are 150 mg twice daily or 300 mg at bedtime. The maintenance dose is 150 mg daily.
  • Erosive esophagitis is treated with 150 mg 4 times daily.
  • Zollinger Ellison syndrome may be treated with as much as 6 g daily.
  • Heartburn is treated with 75 mg or 150 mg once or twice daily 30-60 minutes before consuming meals or beverages that cause heartburn.

Self-medication should not last longer than 2 weeks unless advised by a physician.

DRUG INTERACTIONS: Ranitidine, like other drugs that reduce stomach acid, may interfere with the absorption of drugs that require acid for adequate absorption. Examples include iron salts (for example iron sulphate), itraconazole (Sporanox), and ketoconazole (Nizoral, Extina, Xolegel, Kuric).

PREGNANCY: There are no adequate studies of ranitidine in pregnant women. Available evidence suggests that there is little risk when used during pregnancy.

NURSING MOTHERS: Ranitidine is secreted into human breast milk and may pose a potential risk to the infant.

SIDE EFFECTS: Minor side effects include constipation, diarrhea, fatigue, headache, insomnia, muscle pain, nausea, and vomiting. Major side effects are rare; they include: agitation, anemia, confusion, depression, easy bruising or bleeding, hallucinations, hair loss, irregular heartbeat, rash, visual changes, and yellowing of the skin or eyes.

Reference: FDA Prescribing Information


Last Editorial Review: 2/11/2011




Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Pill Finder Tool

Need help identifying pills and medications?
Use the pill identifier tool on RxList.


Back to Medications Index

STAY INFORMED

Get the Latest health and medical information delivered direct to your inbox!