Drug

Cimetidine

Common brand names:

Acid Reducer 200, Tagamet, Tagamet HB

Cimetidine is a member of the H-2 blocker (histamine blocker) family of drugs that prevents the release of acid into the stomach. Cimetidine is used to treat stomach and duodenal ulcers, reflux of stomach acid into the esophagus, and Zollinger-Ellison syndrome. Cimetidine is available as a prescription drug and as a nonprescription over-the-counter product for relief of heartburn.

Summary of Interactions with Vitamins, Herbs, & Foods

  • Negative Interactions

    2
    • Cimetidine

      Foods with Caffeine

      Potential Negative Interaction

      Caffeine is found in coffee, tea, soft drinks, chocolate, guaraná (Paullinia cupana), nonprescription over-the-counter drug products, and supplement products containing caffeine or guaraná. Cimetidine may decrease the clearance of caffeine from the body, causing increased caffeine blood levels and unwanted actions. People taking cimetidine may choose to limit their caffeine intake to avoid problems. They should read food, beverage, drug, and supplement labels carefully for caffeine content.

      Foods with Caffeine
      Cimetidine
      ×
      1. Threlkeld DS, ed. Central Nervous System Drugs, Analeptics, Caffeine. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Feb 1998, 230-d.
    • Cimetidine

      Magnesium

      Reduces Effectiveness

      In healthy volunteers, a magnesium hydroxide/aluminum hydroxide antacid, taken with cimetidine, decreased cimetidine absorption by 20 to 25%. People can avoid this interaction by taking cimetidine two hours before or after any aluminum/magnesium-containing antacids, including magnesium hydroxide found in some vitamin/mineral supplements. However, the available studies do not clearly indicate if magnesium hydroxide was the problem and may not need to be avoided.

      Magnesium
      Cimetidine
      ×
      1. Bachmann KA, Sullivan TJ, Jauregui L, et al. Drug interactions of H2-receptor antagonists. Scand J Gastroenterol Suppl 1994;206:14-9.
  • Supportive Interactions

    6
    • Cimetidine

      Beta-Carotene

      Replenish Depleted Nutrients

      This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

      Omeprazole, a drug closely related to lansoprazole, taken for seven days led to a near-total loss of stomach acid in healthy people and interfered with the absorption of a single administration of 120 mg of beta-carotene. It is unknown whether repeated administration of beta-carotene would overcome this problem or if absorption of carotenoids from food would be impaired. Persons taking omeprazole and related acid-blocking drugs for long periods may want to have carotenoid blood levels checked, eat plenty of fruits and vegetables, and consider supplementing with carotenoids.

      Beta-Carotene
      Cimetidine
      ×
      1. Tang G, Serfaty-Lacronsniere C, Camilo ME, Russell RM. Gastric acidity influences the blood response to a beta-carotene dose in humans. Am J Clin Nutr 1996;64:622-6.
    • Cimetidine

      Copper

      Replenish Depleted Nutrients

      This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

      There is some evidence that other vitamins and minerals, such as folic acid and copper, require the presence of stomach acid for optimal absorption. Long-term use of H-2 blockers may therefore promote a deficiency of these nutrients. Individuals requiring long-term use of H-2 blockers may therefore benefit from a multiple vitamin/mineral supplement.

      Copper
      Cimetidine
      ×
      1. Russell RM, Krasinski SD, Samloff IM. Correction of impaired folic acid (Pte Glu) absorption by orally administered HCl in subjects with gastric atrophy. Am J Clin Nutr 1984;39:656.
      2. Tompsett SL. Factors influencing the absorption of iron and copper from the alimentary tract. Biochem J 1940;34:961-9.
    • Cimetidine

      Folic Acid

      Replenish Depleted Nutrients

      This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

      Folic acid is needed by the body to utilize vitamin B12. Antacids, including nizatidine, inhibit folic acid absorption. However, folic acid supplementation can mask a vitamin B12 deficiency. Therefore, people taking antacids are advised to supplement with folic acid and vitamin B12.

      There is some evidence that other vitamins and minerals, such as folic acid and copper, require the presence of stomach acid for optimal absorption. Long-term use of H-2 blockers may therefore promote a deficiency of these nutrients. Individuals requiring long-term use of H-2 blockers may therefore benefit from a multiple vitamin/mineral supplement.

      Folic Acid
      Cimetidine
      ×
      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. Russell RM, Krasinski SD, Samloff IM. Correction of impaired folic acid (Pte Glu) absorption by orally administered HCl in subjects with gastric atrophy. Am J Clin Nutr 1984;39:656.
      3. Tompsett SL. Factors influencing the absorption of iron and copper from the alimentary tract. Biochem J 1940;34:961-9.
    • Cimetidine

      Iron

      Replenish Depleted Nutrients

      Stomach acid may facilitate iron absorption. H-2 blocker drugs reduce stomach acid and are associated with decreased dietary iron absorption. 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.

      Iron
      Cimetidine
      ×
      1. 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.
    • Cimetidine

      Vitamin B12

      Replenish Depleted Nutrients

      Hydrochloric acid is needed to release vitamin B12 from food so it can be absorbed by the body. Cimetidine, which reduces stomach acid, may decrease the amount of vitamin B12 available for the body to absorb. The vitamin B12 found in supplements is available to the body without the need for stomach acid. Lab tests can determine vitamin B12 levels in people.

      Vitamin B12
      Cimetidine
      ×
      1. Salom IL, Silvis SE, Doscherholmen A. Effect of cimetidine on the absorption of vitamin B12. Scand J Gastroenterol 1982;17:129-31.
    • Cimetidine

      Vitamin D

      Replenish Depleted Nutrients

      Cimetidine may reduce vitamin D activation by the liver. Lab tests can measure activated vitamin D levels in the blood. Forms of vitamin D that do not require liver activation are available, but only by prescription.

      Vitamin D
      Cimetidine
      ×
      1. Anonymous. Cimetidine inhibits the hepatic hydroxylation of vitamin D. Nutr Rev 1985;43:184-5 [review].
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.

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