H2 blockers (drug interactions)
H2 blockers are a class of medications used primarily to reduce stomach acid production, making them effective in treating conditions such as duodenal ulcers, gastric ulcers, peptic ulcers, and Zollinger-Ellison syndrome. While beneficial, H2 blockers can interact with various nutrients and substances. For instance, they may impair the absorption of vitamin B12, necessitating supplementation for those using these drugs regularly. Additionally, H2 blockers potentially reduce folate and mineral absorption, suggesting that supplementation with these nutrients may be beneficial.
Certain supplements, like magnesium, should be taken at different times than H2 blockers to avoid interference with absorption. Cimetidine, a specific H2 blocker, may affect vitamin D metabolism, although further research is needed to understand its significance fully. Moreover, H2 blockers can inhibit the absorption of antifungal medications and antacids, which should also be taken separately. Patients are advised to exercise caution with herbal supplements like ginkgo biloba and St. John’s wort, as they may pose additional risks. Overall, awareness of these interactions is vital for those using H2 blockers to ensure optimal effectiveness and nutrient absorption.
H2 blockers (drug interactions)
DEFINITION: Medications used to decrease the production of stomach acid. In addition, H2 blockers can be used to treat duodenal ulcers, gastric ulcers, and certain conditions, such as Zollinger-Ellison syndrome. This is where acid-producing cells produce a tumor in the digestive tract. H2 blockers can also be effective against a class of ulcers known as Peptic ulcers. These are where ulcers, or sores, form where a protective layer of mucus is exposed in the stomach or small intestine.
INTERACTIONS: Folate, magnesium, minerals, vitamin B12, vitamin D, calcium, ginkgo biloba, St. John's wort, antifungal medications, antacids
DRUGS IN THIS FAMILY: Cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), ranitidine hydrochloride (Zantac)
Vitamin B12
Effect: Probable Need for Supplementation
H2-receptor blockers appear to impair the absorption of vitamin B12 from food. This is thought to occur because the vitamin B12 in food is attached to proteins. Stomach acid separates them and allows the B12 to be absorbed.
Persons who regularly use H2 blockers should take vitamin B12 supplements. These supplements can be absorbed easily because they are not attached to proteins.
Folate
Effect: Supplementation Possibly Helpful
There is some evidence that H2 blockers may slightly reduce folate absorption. Folate is an important nutrient that is commonly deficient in the diet. Experts recommend that persons taking H2 blockers also take folate supplements.
Minerals
Effect: Supplementation Possibly Helpful
H2 blockers might interfere with the absorption of iron, zinc, and perhaps other minerals by reducing stomach acid levels. Taking mineral supplements that provide the US Dietary Reference Intake (formerly known as the Recommended Dietary Allowance) of these substances should help.
Magnesium
Effect: Take at a Different Time of Day
Magnesium supplements may interfere with the absorption of H2 blockers. However, the interference may be too minor to cause a real problem. Persons who believe their magnesium supplements are interfering with their medication should take these minerals a minimum of two hours before or after taking an H2-blocking medication.
Vitamin D
Effect: Possible Inhibition by Cimetidine
Cimetidine may interfere with vitamin D metabolism, but other H2 blockers may not interact. It is not known whether taking more vitamin D is useful.
Other Interactions
There are several other interactions between H2 blockers and herbs, supplements, and prescription medications. In addition to magnesium, patients are advised to take a calcium supplement twice a day at least two hours before or after taking H2 blockers. This is because H2 blockers can reduce the absorption of calcium from one’s diet. Though no formal studies have confirmed this, ginkgo biloba may increase the risk of bleeding. Patients taking H2 blockers should also avoid St. John’s wort. H2 blockers may also inhibit the absorption of antifungal medications or antacids, which should be taken at different times. Finally, some medications, such as iron supplements or antiviral drugs, need an acidic environment to be properly absorbed. Since H2 blockers decrease acidity, the absorption of these drugs is affected.
Bibliography
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