Omeprazole
Pronounced
"oh-MEH-pruh-zole"
Drug Interactions
See also How to Use section.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug include: clopidogrel, mavacamten, methotrexate (especially high-dose treatment), rifampin, St John's wort.
Some products need stomach acid so that the body can absorb them properly. Omeprazole decreases stomach acid, so it may change how well these products work. Some affected products include atazanavir, erlotinib, levoketoconazole, nelfinavir, pazopanib, rilpivirine, sparsentan, certain azole antifungals (itraconazole, ketoconazole, posaconazole), among others.
Omeprazole is very similar to esomeprazole. Do not use any medications containing esomeprazole while using omeprazole.
This medication may interfere with certain lab tests, possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
Negative Interactions
1- Reduces Effectiveness
Omeprazole
St. John’s Wort
In a study of healthy human volunteers, supplementing with St. John's wort greatly decreased omeprazole blood levels by accelerating the metabolism of the drug. Use of St. John's wort may, therefore, interfere with the actions of omeprazole.
St. John’s WortOmeprazole- Wang LS, Zhou G, Zhu B, et al. St John's wort induces both cytochrome P450 3A4-catalyzed sulfoxidation and 2C19-dependent hydroxylation of omeprazole. Clin Pharmacol Ther 2004;75:191-7.
Supportive Interactions
5- Replenish Depleted Nutrients
Omeprazole
Calcium
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.
In a study of elderly women, administration of omeprazole decreased the absorption of calcium, presumably because the drug decreased the stomach's production of hydrochloric acid, which is necessary for calcium absorption. The form of calcium used in the study to test calcium absorption was calcium carbonate. Drugs that reduce stomach acid secretion may not inhibit other forms of calcium, such as calcium citrate.
CalciumOmeprazole- O'Connell MB, Madden DM, Murray AM, et al. Effects of proton pump inhibitors on calcium carbonate absorption in women: a randomized crossover trial. Am J Med 2005;118:778-81.
- Recker RR. Calcium absorption and achlorhydria. N Engl J Med 1985;313:70-3.
- Replenish Depleted Nutrients
Omeprazole
Folic Acid
Folic acid is needed by the body to utilize vitamin B12. Antacids, including omeprazole, inhibit folic acid absorption. People taking antacids are advised to supplement with folic acid.
Folic AcidOmeprazole- 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.
- Replenish Depleted Nutrients
Omeprazole
Vitamin B12
Omeprazole interferes with the absorption of vitamin B12 from food (though not from supplements) in some but not all studies. A true deficiency state, resulting in vitamin B12-deficiency anemia, has only been reported in one case. The fall in vitamin B12 status may result from the decrease in stomach acid required for vitamin B12 absorption from food caused by the drug. This problem may possibly be averted by drinking acidic juices when eating foods containing vitamin B12.
However, all people taking omeprazole need to either supplement with vitamin B12 or have their vitamin B12 status checked on a yearly basis. Even relatively small amounts of vitamin B12 such as 10–50 mcg per day, are likely to protect against drug induced vitamin depletion.
Vitamin B12Omeprazole- Marcuard SP, Albernaz L, Khazanie PG. Omeprazole therapy causes malabsorption of cyanocobalamin (Vitamin B12). Ann Intern Med 1994;120:211-5.
- Termanini B, Gibril F, Sutliff VE, et al. Effect of long-term gastric acid suppressive therapy on serum vitamin B12 levels in patients with Zollinger-Ellison syndrome. Am J Med 1998;104:422-30.
- Koop H. Review article: metabolic consequences of long-term inhibition of acid secretion by omeprazole. Aliment Pharmacol Ther 1992;6:399-406 [review].
- Bellou A, Aimone-Gastin I, De Korwin JD, et al. Cobalamin deficiency with megaloblastic anaemia in one patient under long-term omeprazole therapy. J Intern Med 1996;240:161-4.
- Koop H, Bachem MG. Serum iron, ferritin, and vitamin B12 during prolonged omeprazole therapy. J Clin Gastroenterol 1992;14:288-92.
- Schenk BE, Festen HP, Kuipers EJ, et al. Effect of short-and long-term treatment with omeprazole on the absorption and serum levels of cobalamin. Aliment Pharmacol Ther 1996;10:541-5.
- Saltzman JR, Kemp JA, Golner BB, et al. Effect of hypochlorhydria due to omeprazole treatment or atrophic gastritis on protein-bound vitamin B12 absorption. J Am Coll Nutr 1994;13:584-91.
- Bradford GS, Taylor CT. Omeprazole and vitamin B12 deficiency. Ann Pharmacother 1999;33:641-3 [review].
- Replenish Depleted Nutrients
Omeprazole
Vitamin C
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.
Treatment of healthy volunteers with omeprazole for four weeks resulted in a 12.3% decrease in blood levels of vitamin C.
Vitamin COmeprazole- Henry EB, Carswell A, Wirz A, et al. Proton pump inhibitors reduce the bioavailability of dietary vitamin C. Aliment Pharmacol Ther2005;22:539-5.
- Reduce Side Effects
Omeprazole
Cranberry
People taking omeprazole may increase absorption of dietary vitamin B12 by drinking cranberry (Vaccinium marocarpon) juice or other acidic liquids with vitamin B12-containing foods.
CranberryOmeprazole- Saltzman JR, Kemp JA, Golner BB, et al. Effect of hypochlorhydria due to omeprazole treatment or atrophic gastritis on protein-bound vitamin B12 absorption. J Am Coll Nutr 1994;13:584-91.
Explanation Required
1- Needs Explanation
Omeprazole
Magnesium
In a case report, a man developed severe magnesium deficiency after long-term treatment with a proton pump inhibitor (pantoprazole or lansoprazole). Severe magnesium deficiency as a result of the use of proton pump inhibitors appears to be rare among people who have no other risk factors for magnesium deficiency. However, in a study of hospitalized patients, the prevalence of low serum magnesium levels was significantly greater among users of proton pump inhibitors than among nonusers (23% vs. 11%). People taking proton pump inhibitors (PPIs) should ask their doctor whether to take a magnesium supplement or whether to have their magnesium levels monitored.MagnesiumOmeprazole- Regolisti G, Cabassi A, Parenti E, et al. Severe hypomagnesemia during long-term treatment with a proton pump inhibitor. Am J Kidney Dis 2010;56:168-74.
- Gau JT, Yang YX, Chen R, Kao TC. Uses of proton pump inhibitors and hypomagnesemia. Pharmacoepidemiol Drug Saf 2012;21:553-9.
- FDA Drug Safety Communication: Low magnesium levels can be associated with long-term use of Proton Pump Inhibitor drugs (PPIs). U.S. Food and Drug Administration [cited 2011 Sept 13]. Available from URL: http://www.fda.gov/drugs/drugsafety/ucm245011.htm#Additional_Information_for_Patients on.
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