Ranitidine is a member of the H-2 (histamine blocker) family of drugs, which prevents the release of acid into the stomach. Ranitidine is used to treat stomach and duodenal ulcers, gastroesophageal reflux disease, erosive esophagitis, and Zollinger-Ellison syndrome. Ranitidine is available as a prescription drug and also as a nonprescription over-the-counter product for relief of heartburn.
Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.
 May be Beneficial: Depletion or interference—The medication may deplete or interfere with the absorption or function of the nutrient. Taking these nutrients may help replenish them. | Folic acid Iron Vitamin B12* |
 Avoid: Reduced drug absorption/bioavailability—Avoid these supplements when taking this medication since the supplement may decrease the absorption and/or activity of the medication in the body. | Magnesium hydroxide Tobacco |
| Side effect reduction/prevention | None known |
| Supportive interaction | None known |
| Adverse interaction | None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
Folic acid
Folic acid is needed by the body to utilize vitamin B12. Antacids, including ranitidine, inhibit folic acid absorption.1 People taking antacids are advised to supplement with folic acid.
Iron
Stomach acid may facilitate iron absorption. H-2 blocker drugs reduce stomach acid and are associated with decreased dietary iron absorption.2 People with ulcers may also be iron deficient due to blood loss and benefit from iron supplementation. Iron levels in the blood can be checked with lab tests.
Magnesium
In healthy volunteers, a magnesium hydroxide/aluminum hydroxide antacid, taken with ranitidine, decreased ranitidine absorption by 20%–25%.3 It was unclear from this study if magnesium or the specific form of magnesium as magnesium hydroxide was part of the problem. It is not known if other forms of magnesium would cause this problem. People can avoid this interaction by taking ranitidine two hours before or after any aluminum/magnesium-containing antacids, including magnesium hydroxide found in some vitamin/mineral supplements.
Vitamin B12
Stomach acid is needed to release vitamin B12 from food so it can be absorbed by the body. H-2 blocker drugs reduce stomach acid and are associated with decreased dietary vitamin B12 absorption.4 The vitamin B12 found in supplements is available to the body without the need for stomach acid. Lab tests can determine vitamin B12 levels.
Interactions with Foods and Other Compounds
Food
Ranitidine may be taken with or without food.5
Tobacco (Nicotiana species)
A study of 18 healthy people found smoking decreased the acid blocking effects of ranitidine.6
References
1. Russell RM, Golner BB, Krasinski SD, et al. Effect of antacid and H2 receptor antagonists on the intestinal absorption of folic acid. J Lab Clin Med 1988;112:458–63.
2. Aymard JP, Aymard B, Netter P, et al. Haematological adverse effects of histamine H2-receptor antagonists. Med Toxicol Adverse Drug Exp 1988;3:430–48.
3. Bachmann KA, Sullivan TJ, Jauregui L, et al. Drug interactions of H2-receptor antagonists. Scand J Gastroenterol Suppl 1994;206:14–9.
4. Aymard JP, Aymard B, Netter P, et al. Haematological adverse effects of histamine H2-receptor antagonists. Med Toxicol Adverse Drug Exp 1988;3:430–48.
5. Threlkeld DS, ed. Gastrointestinal Drugs, Histamine H2 Antagonists. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Sep 1995, 305d–5e.
6. Schurer-Maly CC, Varga L, Koelze HR, Halter F. Smoking and pH response to H2-receptor antagonists. Scand J Gastroenterol 1989;24:1172–8.
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2006-09-07
