Famotidine (PF)
Pronounced
"fam-OH-tih-dine"
Drug Interactions
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.
A product that may interact with this drug is: fezolinetant.
Some products need stomach acid so that the body can absorb them properly. Famotidine decreases stomach acid, so it may change how well these products work. Some affected products include atazanavir, dasatinib, certain azole antifungals (such as itraconazole, ketoconazole), levoketoconazole, pazopanib, sparsentan, among others.
Do not take this medication with other products that contain famotidine or other H2 blockers (cimetidine, nizatidine, ranitidine).
Negative Interactions
1- Reduces Effectiveness
Famotidine
Magnesium
In healthy people, a magnesium hydroxide/aluminum hydroxide antacid, taken with famotidine, decreased famotidine absorption by 20–25%. People can avoid this interaction by taking famotidine two hours before or after any aluminum/magnesium-containing antacids. Some magnesium supplements such as magnesium hydroxide are also antacids.
MagnesiumFamotidine- Bachmann KA, Sullivan TJ, Jauregui L, et al. Drug interactions of H2-receptor antagonists. Scand J Gastroenterol Suppl 1994;206:14-9.
Supportive Interactions
5- Replenish Depleted Nutrients
Famotidine
Beta-Carotene
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-CaroteneFamotidine- 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.
- Replenish Depleted Nutrients
Famotidine
Copper
Some evidence indicates 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.
CopperFamotidine- 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.
- Tompsett SL. Factors influencing the absorption of iron and copper from the alimentary tract. Biochem J 1940;34:961-9.
- Replenish Depleted Nutrients
Famotidine
Folic Acid
Some evidence indicates 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 AcidFamotidine- 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.
- Tompsett SL. Factors influencing the absorption of iron and copper from the alimentary tract. Biochem J 1940;34:961-9.
- Replenish Depleted Nutrients
Famotidine
Iron
Stomach acid may increase absorption of iron from food. H-2 blocker drugs reduce stomach acid and are associated with decreased dietary iron absorption. The iron found in supplements is available to the body without the need for stomach acid. People with ulcers may be iron deficient due to blood loss. If iron deficiency is present, iron supplementation may be beneficial. Iron levels in the blood can be checked with lab tests.
IronFamotidine- 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.
- Replenish Depleted Nutrients
Famotidine
Vitamin B12
Stomach acid is needed for the vitamin B12 in food to be absorbed. H-2 blocker drugs reduce stomach acid and may therefore inhibit absorption of the vitamin B12 naturally present in food. However, the vitamin B12 found in supplements does not depend on stomach acid for absorption. Lab tests can determine vitamin B12 levels in people.
Vitamin B12Famotidine- 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.
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