Ferric maltol is an oral iron replacement therapy approved for iron-deficiency anemia in adults. Ferric maltol contains iron in a stable ferric state as a complex with a trimaltol ligand. Iron is an essential mineral and is a component of hemoglobin, myoglobin, and multiple enzymes. The anemia of iron deficiency may result in fatigue, exertional shortness of breath, tachycardia, pallor, headache, glossitis, koilonychia (spoon nails), and decreased cognitive functioning. The safety and efficacy of ferric maltol for the treatment of iron-deficiency anemia in patients with inflammatory bowel disease (IBD) and chronic kidney disease (CKD) was established in 3 clinical studies. In all studies, the primary efficacy outcome was the mean change in hemoglobin concentration from baseline to study end (least square (LS) mean difference) between ferric maltol and placebo. In patients with IBD, the LS mean difference was 2.18 g/dL at week 12. In patients with CKD, the LS mean difference was 0.52 g/dL at week 16. The mean change in ferritin concentrations from baseline to study end was also significantly higher in ferric maltol-treated patients compared with placebo. As with other iron supplements, gastrointestinal adverse effects are common with ferric maltol; however, it is recommended that ferric maltol be taken on an empty stomach to increase absorption.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Oral Administration
Oral Solid Formulations
-Administer on an empty stomach, at least one hour before or two hours after meals.
-Do not open, break, or chew capsules.
The most common adverse reactions reported in the placebo-controlled phase in clinical studies with ferric maltol (n = 175) were gastrointestinal in nature and included flatulence (4.6%), diarrhea (4%), constipation (4%), stool discoloration (4%), abdominal pain (2.9%), nausea (1.7%), vomiting (1.7%), abdominal discomfort (1.1%), and abdominal distention (1.1%). The most common adverse reaction leading to therapy discontinuation of ferric maltol was abdominal pain (1.7% of patients).
Ferric maltol is contraindicated in patients with hemochromatosis and other iron overload syndromes and patients receiving repeated blood transfusions. Excessive therapy with iron products may lead to excess storage of iron and iatrogenic hemosiderosis. Do not administer ferric maltol to patients receiving intravenous iron or evidence of iron overload. Monitor iron parameters prior to initiating ferric maltol and during therapy.
Avoid use of ferric maltol in patients with an active inflammatory bowel disease (i.e., ulcerative colitis, Crohn's disease) flare, as there is a potential risk for increased inflammation in the gastrointestinal tract.
Accidental exposure of iron-containing products (i.e., overdose) is the leading cause of fatal poisoning in children under the age of 6 years. Always store any iron-containing products out of the reach of children and pets. In the case of accidental exposure by ingestion, call a physician or poison control center immediately.
Ferric maltol is not absorbed systemically as an intact complex following administration and maternal use during pregnancy is not expected to result in fetal exposure to the drug. Animal reproduction studies with oral doses of ferric compounds resulted in no adverse developmental outcomes. An overdose of iron during pregnancy may increase the risk of spontaneous abortion, gestational diabetes, and fetal malformations.
There are no data available on the presence of ferric maltol in breast milk, the effects on the breastfed child, or the effects on milk production. However, ferric maltol is not absorbed systemically as an intact complex following oral administration, and breast-feeding is not expected to result in exposure to the child.
The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents (e.g., geriatric adults) of long-term care facilities (LTCFs). According to the OBRA guidelines, iron therapy is not indicated in anemia of chronic disease when iron stores and transferrin levels are normal or elevated. Clinical rationale should be documented for long-term use (greater than 2 months) or more than once daily administration for longer than a week, because of side effects and the risk of iron accumulation in tissues. Monitoring should include a baseline serum iron or ferritin level and periodic complete blood count (CBC) or hematocrit/hemoglobin measurements. Adverse consequences of iron therapy include constipation and dyspepsia. Iron can accumulate in tissues and cause multiple complications if given chronically in the presence of normal or high iron stores.
For the treatment of iron-deficiency anemia:
Oral dosage:
Adults: 30 mg PO twice daily for as long as necessary until ferritin concentrations are within the normal range. Treatment duration will depend on the severity of iron deficiency, but 12 weeks or more of treatment is usually required.
Maximum Dosage Limits:
-Adults
60 mg/day PO.
-Geriatric
60 mg/day PO.
-Adolescents
Safety and efficacy have not been established.
-Children
Safety and efficacy have not been established.
-Infants
Safety and efficacy have not been established.
-Neonates
Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.
Patients with Renal Impairment Dosing
Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.
*non-FDA-approved indication
Abacavir; Dolutegravir; Lamivudine: (Moderate) Administer dolutegravir 2 hours before or 6 hours after taking supplements containing iron if given under fasting conditions. When taken with food, dolutegravir and supplements containing iron can be taken at the same time. Simultaneous administration under fasted conditions may result in reduced bioavailability of dolutegravir.
Acetohydroxamic Acid: (Moderate) Acetohydroxamic acid chelates heavy metals, including iron. Absorption of orally administered iron salts or polysaccharide-iron complex and acetohydroxamic acid from the intestinal lumen may be reduced when both drugs are administered concomitantly. If iron therapy is required in a patient currently taking acetohydroxamic acid, intramuscular iron is recommended.
Alendronate: (Moderate) Separate administration of alendronate and iron supplements by at least 30 minutes. Iron will interfere with the absorption of alendronate.
Alendronate; Cholecalciferol: (Moderate) Separate administration of alendronate and iron supplements by at least 30 minutes. Iron will interfere with the absorption of alendronate.
Aluminum Hydroxide: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Aluminum Hydroxide; Magnesium Carbonate: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Aluminum Hydroxide; Magnesium Hydroxide: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Aluminum Hydroxide; Magnesium Trisilicate: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Amoxicillin; Clarithromycin; Omeprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Antacids: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Aspirin, ASA; Omeprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Baloxavir Marboxil: (Major) Avoid concomitant use of baloxavir with oral dietary supplements containing iron. Oral iron interferes with baloxavir absorption and may reduce baloxavir efficacy. In animal studies, polyvalent cations like iron reduced baloxavir overall exposure by 48% to 63%.
Bictegravir; Emtricitabine; Tenofovir Alafenamide: (Moderate) Administer bictegravir with food at the same time as iron supplements. Routine administration of bictegravir under fasting conditions simultaneously with, or 2 hours after, iron supplements is not recommended. Iron is a polyvalent cation that can bind bictegravir in the GI tract. Taking these drugs simultaneously without food results in reduced bioavailability of bictegravir. In drug interaction studies, simultaneous administration of bictegravir and ferrous fumarate under fasted conditions decreased the mean AUC of bictegravir by approximately 63%.
Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Cabotegravir: (Moderate) Administer oral iron at least two hours before or four hours after taking oral cabotegravir. Iron is a polyvalent cation that can bind cabotegravir in the GI tract. Taking these drugs simultaneously may result in reduced oral bioavailability of cabotegravir.
Cabotegravir; Rilpivirine: (Moderate) Administer oral iron at least two hours before or four hours after taking oral cabotegravir. Iron is a polyvalent cation that can bind cabotegravir in the GI tract. Taking these drugs simultaneously may result in reduced oral bioavailability of cabotegravir.
Calcium Carbonate: (Moderate) Antacids (e.g., calcium carbonate, aluminum hydroxide, or magnesium hydroxide) may decrease the absorption of oral iron preparations (e.g., iron salts or polysaccharide-iron complex). At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed. Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction.
Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Moderate) Antacids (e.g., calcium carbonate, aluminum hydroxide, or magnesium hydroxide) may decrease the absorption of oral iron preparations (e.g., iron salts or polysaccharide-iron complex). At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed. Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. (Minor) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of H2-blockers can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. H2-blockers have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Calcium Carbonate; Magnesium Hydroxide: (Moderate) Antacids (e.g., calcium carbonate, aluminum hydroxide, or magnesium hydroxide) may decrease the absorption of oral iron preparations (e.g., iron salts or polysaccharide-iron complex). At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed. Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction.
Calcium Carbonate; Magnesium Hydroxide; Simethicone: (Moderate) Antacids (e.g., calcium carbonate, aluminum hydroxide, or magnesium hydroxide) may decrease the absorption of oral iron preparations (e.g., iron salts or polysaccharide-iron complex). At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed. Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction.
Calcium Carbonate; Simethicone: (Moderate) Antacids (e.g., calcium carbonate, aluminum hydroxide, or magnesium hydroxide) may decrease the absorption of oral iron preparations (e.g., iron salts or polysaccharide-iron complex). At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed. Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction.
Calcium; Vitamin D: (Moderate) Antacids (e.g., calcium carbonate, aluminum hydroxide, or magnesium hydroxide) may decrease the absorption of oral iron preparations (e.g., iron salts or polysaccharide-iron complex). At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed. Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction.
Carbidopa; Levodopa: (Moderate) Administration of iron salts, including polysaccharide-iron complex or multivitamins containing iron, should be separated from oral levodopa by at least 2 hours to avoid reduction in levodopa efficacy. Iron salts may reduce the bioavailability of levodopa and carbidopa; levodopa products.
Carbidopa; Levodopa; Entacapone: (Moderate) Administration of iron salts, including polysaccharide-iron complex or multivitamins containing iron, should be separated from oral levodopa by at least 2 hours to avoid reduction in levodopa efficacy. Iron salts may reduce the bioavailability of levodopa and carbidopa; levodopa products.
Cefdinir: (Moderate) Administer cefdinir at least 2 hours before or 2 hours after iron supplements. Cefdinir absorption may be reduced. Coadministration of cefdinir with a therapeutic iron supplement containing 60 mg of elemental iron or vitamins supplemented with 10 mg of elemental iron reduced extent of absorption by 80% and 31%, respectively.
Chlorpheniramine; Pseudoephedrine: (Moderate) Orally administered zinc salts compete with iron supplements for absorption from the intestine. To minimize the interaction, separate oral iron and zinc doses by at least 2 hours. The oral receipt of 100 mg of iron as ferrous gluconate with 12 mg zinc in 11 patients with normal iron status and comparable total exchangeable zinc pools yielded a mean zinc absorption of 26.4% +/- 14.4% of the administered dose as compared with 44.5% +/- 22.5% of the dose given without concomitant iron. Concomitant use of iron 400 mg as ferrous gluconate yielded a mean zinc absorption of 22.9% +/- 6.4% of the zinc dose.
Cholestyramine: (Moderate) Concurrent administration of cholestyramine and oral iron supplements may reduce the oral absorption of iron. To avoid any oral absorption interference, administration of other drugs is recommended 1 hour before or at least 4 to 6 hours after cholestyramine administration.
Cimetidine: (Minor) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of H2-blockers can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. H2-blockers have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Ciprofloxacin: (Moderate) Administer oral ciprofloxacin at least 2 hours before or 6 hours after oral products that contain iron. Ciprofloxacin absorption may be reduced as quinolone antibiotics can chelate with divalent or trivalent cations.
Delafloxacin: (Major) Administer oral delafloxacin at least 2 hours before or 6 hours after oral products that contain iron. Delafloxacin absorption may be reduced as quinolone antibiotics can chelate with divalent or trivalent cations. Examples of compounds that may interfere with quinolone bioavailability include multivitamins that contain iron.
Demeclocycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Dexlansoprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Didanosine, ddI: (Moderate) Iron salts should not be administered simultaneously with didanosine, ddI chewable tablets or powder for oral solution. Oral absorption of iron supplements is reduced if given with antacids; the buffering agents contained in didanosine tablets and powder likewise reduce iron salt absorption. Administer oral doses of iron salts 1 hour before or 4 hours after didanosine tablet or powder administration. The delayed-release didanosine capsules do not contain a buffering agent and would not be expected to interact with iron salts.
Dimercaprol: (Major) Avoid concomitant use of dimercaprol and products containing iron. Dimercaprol forms toxic-chelates with iron which increases the risk for nephrotoxicity and other adverse effects.
Dolutegravir: (Moderate) Administer dolutegravir 2 hours before or 6 hours after taking supplements containing iron if given under fasting conditions. When taken with food, dolutegravir and supplements containing iron can be taken at the same time. Simultaneous administration under fasted conditions may result in reduced bioavailability of dolutegravir.
Dolutegravir; Lamivudine: (Moderate) Administer dolutegravir 2 hours before or 6 hours after taking supplements containing iron if given under fasting conditions. When taken with food, dolutegravir and supplements containing iron can be taken at the same time. Simultaneous administration under fasted conditions may result in reduced bioavailability of dolutegravir.
Dolutegravir; Rilpivirine: (Moderate) Administer dolutegravir 2 hours before or 6 hours after taking supplements containing iron if given under fasting conditions. When taken with food, dolutegravir and supplements containing iron can be taken at the same time. Simultaneous administration under fasted conditions may result in reduced bioavailability of dolutegravir.
Doxycycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Eltrombopag: (Major) Eltrombopag chelates polyvalent cations (e.g., iron) in foods and mineral supplements. In a clinical study, systemic exposure to eltrombopag was decreased by 70% when it was administered with a polyvalent cation-containing antacid. Administer eltrombopag at least 2 hours before or 4 hours after any oral products containing polyvalent cations, such as iron salts, multivitamins that contain iron, or polysaccharide-iron complex.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Moderate) Separate administration of elvitegravir and iron by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Separate administration of elvitegravir and iron by at least 2 hours. Due to the formation of ionic complexes in the gastrointestinal tract, simultaneous administration results in lower elvitegravir plasma concentrations.
Enteral Feedings: (Minor) Ferrous sulfate elixir has an acidic pH and has been reported to form precipitates with enteral feedings and may clog feeding tubes.
Esomeprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Etidronate: (Moderate) Separate administration of oral etidronate and iron supplements by at least 2 hours. Iron will interfere with the absorption of oral etidronate.
Famotidine: (Minor) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of H2-blockers can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. H2-blockers have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Ferric carboxymaltose: (Major) Parenteral iron formulas are generally only indicated for use in patients with documented iron deficiency in whom oral administration is either impossible or unsatisfactory. In general, do not administer parenteral iron concomitantly with other iron preparations (e.g., other parenteral iron products or oral iron supplements). Parenteral iron preparations (e.g., iron dextran; iron sucrose, sucroferric oxyhydroxide; sodium ferric gluconate complex; ferric carboxymaltose; ferumoxytol) may reduce the absorption of concomitantly administered oral iron preparations. Oral iron supplementation should be discontinued before parenteral administration of iron. Too much iron can be toxic, and iron is not easily eliminated from the body.
Ferric Derisomaltose: (Major) Parenteral iron formulas are generally only indicated for use in patients with documented iron deficiency in whom oral administration is either impossible or unsatisfactory. In general, do not administer parenteral iron concomitantly with other iron preparations (e.g., other parenteral iron products or oral iron supplements). Parenteral iron preparations (e.g., iron dextran; iron sucrose, sucroferric oxyhydroxide; sodium ferric gluconate complex; ferric carboxymaltose; ferumoxytol) may reduce the absorption of concomitantly administered oral iron preparations. Oral iron supplementation should be discontinued before parenteral administration of iron. Too much iron can be toxic, and iron is not easily eliminated from the body.
Ferumoxytol: (Major) Parenteral iron formulas are generally only indicated for use in patients with documented iron deficiency in whom oral administration is either impossible or unsatisfactory. In general, do not administer parenteral iron concomitantly with other iron preparations (e.g., other parenteral iron products or oral iron supplements). Parenteral iron preparations (e.g., iron dextran; iron sucrose, sucroferric oxyhydroxide; sodium ferric gluconate complex; ferric carboxymaltose; ferumoxytol) may reduce the absorption of concomitantly administered oral iron preparations. Oral iron supplementation should be discontinued before parenteral administration of iron. Too much iron can be toxic, and iron is not easily eliminated from the body.
Food: (Major) For better iron absorption, administer iron salts 1 hour before or 2 hours after meals. If GI irritation occurs, the iron supplement may be administered with meals. However, where possible, avoid administering coffee, tea, or dairy products within 1 hour before or 2 hours after giving iron.
Gemifloxacin: (Major) Administer oral products that contain iron at least 3 hours before or 2 hours after gemifloxacin. Gemifloxacin absorption may be reduced as quinolone antibiotics can chelate with divalent or trivalent cations. Examples of compounds that may interfere with quinolone bioavailability include multivitamins that contain iron.
Green Tea: (Major) Green tea has been shown to inhibit the absorption of nonheme iron. When possible, do not consume green tea or green tea extract within 1 hour before or 2 hours after giving iron salts.
H2-blockers: (Minor) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of H2-blockers can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. H2-blockers have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Ibandronate: (Moderate) Separate administration of oral ibandronate and iron supplements by at least 1 hour. Iron will interfere with the absorption of oral ibandronate.
Ibritumomab Tiuxetan: (Moderate) It has been reported that high intakes of phosphates, such as are found in dietary supplements or food additives, can interfere with absorption of trace nutrients such as iron, copper, and zinc. The magnitude of the effect may be small, and the interactions require further study to judge clinical significance. The theorized mechanism is the formation of insoluble complexes within the gut. Until more data are available, it may be helpful to separate administration times of phosphates by as much as possible from the oral administration of iron (e.g., iron salts or polysaccharide-iron complex), copper salts, or zinc salts to limit any potential interactions.
Ibuprofen; Famotidine: (Minor) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of H2-blockers can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. H2-blockers have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Iron - Injectable Only: (Major) Parenteral iron formulas are generally only indicated for use in patients with documented iron deficiency in whom oral administration is either impossible or unsatisfactory. In general, do not administer parenteral iron concomitantly with other iron preparations (e.g., other parenteral iron products or oral iron supplements). Parenteral iron preparations (e.g., iron dextran; iron sucrose, sucroferric oxyhydroxide; sodium ferric gluconate complex; ferric carboxymaltose; ferumoxytol) may reduce the absorption of concomitantly administered oral iron preparations. Oral iron supplementation should be discontinued before parenteral administration of iron. Too much iron can be toxic, and iron is not easily eliminated from the body.
Iron Dextran: (Major) Parenteral iron formulas are generally only indicated for use in patients with documented iron deficiency in whom oral administration is either impossible or unsatisfactory. In general, do not administer parenteral iron concomitantly with other iron preparations (e.g., other parenteral iron products or oral iron supplements). Parenteral iron preparations (e.g., iron dextran; iron sucrose, sucroferric oxyhydroxide; sodium ferric gluconate complex; ferric carboxymaltose; ferumoxytol) may reduce the absorption of concomitantly administered oral iron preparations. Oral iron supplementation should be discontinued before parenteral administration of iron. Too much iron can be toxic, and iron is not easily eliminated from the body.
Iron Sucrose, Sucroferric Oxyhydroxide: (Major) Parenteral iron formulas are generally only indicated for use in patients with documented iron deficiency in whom oral administration is either impossible or unsatisfactory. In general, do not administer parenteral iron concomitantly with other iron preparations (e.g., other parenteral iron products or oral iron supplements). Parenteral iron preparations (e.g., iron dextran; iron sucrose, sucroferric oxyhydroxide; sodium ferric gluconate complex; ferric carboxymaltose; ferumoxytol) may reduce the absorption of concomitantly administered oral iron preparations. Oral iron supplementation should be discontinued before parenteral administration of iron. Too much iron can be toxic, and iron is not easily eliminated from the body.
Lansoprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Lanthanum Carbonate: (Major) Oral compounds known to interact with antacids, like iron salts, should not be taken within 2 hours of dosing with lanthanum carbonate. If these agents are used concomitantly, space the dosing intervals appropriately. Monitor serum concentrations and clinical condition.
Levodopa: (Moderate) Administration of iron salts, including polysaccharide-iron complex or multivitamins containing iron, should be separated from oral levodopa by at least 2 hours to avoid reduction in levodopa efficacy. Iron salts may reduce the bioavailability of levodopa and carbidopa; levodopa products.
Levofloxacin: (Moderate) Administer oral products that contain iron at least 2 hours before or 2 hours after orally administered levofloxacin. Levofloxacin absorption may be reduced as quinolone antibiotics can chelate with divalent or trivalent cations. Chelation of divalent cations with levofloxacin is less than with other quinolones.
Levothyroxine: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after the ingestion of iron supplements. Oral iron salts have been reported to chelate oral thyroid hormones within the GI tract when administered simultaneously, leading to decreased oral absorption of the thyroid hormone. For example, ferrous sulfate likely forms a ferric-thyroxine complex.
Levothyroxine; Liothyronine (Porcine): (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after the ingestion of iron supplements. Oral iron salts have been reported to chelate oral thyroid hormones within the GI tract when administered simultaneously, leading to decreased oral absorption of the thyroid hormone. For example, ferrous sulfate likely forms a ferric-thyroxine complex.
Levothyroxine; Liothyronine (Synthetic): (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after the ingestion of iron supplements. Oral iron salts have been reported to chelate oral thyroid hormones within the GI tract when administered simultaneously, leading to decreased oral absorption of the thyroid hormone. For example, ferrous sulfate likely forms a ferric-thyroxine complex.
Liothyronine: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after the ingestion of iron supplements. Oral iron salts have been reported to chelate oral thyroid hormones within the GI tract when administered simultaneously, leading to decreased oral absorption of the thyroid hormone. For example, ferrous sulfate likely forms a ferric-thyroxine complex.
Magnesium Hydroxide: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Magnesium Salts: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Magnesium Sulfate; Potassium Sulfate; Sodium Sulfate: (Major) Administer iron at least 2 hours before or 6 hours after administration of magnesium sulfate; potassium sulfate; sodium sulfate. The absorption of iron may be reduced by chelation with magnesium sulfate.
Methyldopa: (Major) Coadministration of methyldopa with iron salts or polysaccharide-iron complex is not recommended. If iron supplementation is necessary, administer a methyldopa dose at least 2 hours prior to the iron supplement. Iron salts have been reported to dramatically reduce the oral absorption of methyldopa. Several studies demonstrate decreased bioavailability of methyldopa when coadministered with ferrous sulfate or ferrous gluconate. This interaction may result in decreased antihypertensive effect of methyldopa.
Minocycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Moxifloxacin: (Major) Administer oral moxifloxacin at least 4 hours before or 8 hours after oral products that contain iron. Moxifloxacin absorption may be reduced as quinolone antibiotics can chelate with divalent or trivalent cations. Examples of compounds that may interfere with quinolone bioavailability include multivitamins that contain iron.
Mycophenolate: (Moderate) Separate administration of mycophenolate and iron by at least 4 hours. Iron may decrease the oral bioavailability of mycophenolate. Mycophenolate recovery was reduced by up to 16% under certain pH conditions in drug interaction studies.
Naproxen; Esomeprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Nizatidine: (Minor) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of H2-blockers can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. H2-blockers have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Ofloxacin: (Moderate) Administer oral products that contain iron at least 2 hours before or 2 hours after ofloxacin. Ofloxacin absorption may be reduced as quinolone antibiotics can chelate with divalent or trivalent cations.
Omadacycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Omeprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Omeprazole; Amoxicillin; Rifabutin: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Omeprazole; Sodium Bicarbonate: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed. (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Pantoprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Penicillamine: (Major) In general, oral mineral supplements should not be given since they may block the oral absorption of penicillamine. However, iron deficiency may develop, especially in children and menstruating or pregnant women, or as a result of the low copper diet recommended for Wilson's disease. If necessary, iron may be given in short courses, but since iron and penicillamine each inhibit oral absorption of the other, 2 hours should elapse between administration of penicillamine and iron doses.
Phosphorated Carbohydrate Solution: (Moderate) It has been reported that high intakes of phosphates, such as are found in dietary supplements or food additives, can interfere with absorption of trace nutrients such as iron, copper, and zinc. The magnitude of the effect may be small, and the interactions require further study to judge clinical significance. The theorized mechanism is the formation of insoluble complexes within the gut. Until more data are available, it may be helpful to separate administration times of phosphates by as much as possible from the oral administration of iron (e.g., iron salts or polysaccharide-iron complex), copper salts, or zinc salts to limit any potential interactions.
Phosphorus: (Moderate) It has been reported that high intakes of phosphates, such as are found in dietary supplements or food additives, can interfere with absorption of trace nutrients such as iron, copper, and zinc. The magnitude of the effect may be small, and the interactions require further study to judge clinical significance. The theorized mechanism is the formation of insoluble complexes within the gut. Until more data are available, it may be helpful to separate administration times of phosphates by as much as possible from the oral administration of iron (e.g., iron salts or polysaccharide-iron complex), copper salts, or zinc salts to limit any potential interactions.
Polyethylene Glycol; Electrolytes: (Major) Administer iron at least 2 hours before or 6 hours after administration of magnesium sulfate; potassium sulfate; sodium sulfate. The absorption of iron may be reduced by chelation with magnesium sulfate.
Polyethylene Glycol; Electrolytes; Ascorbic Acid: (Major) Administer iron at least 2 hours before or 6 hours after administration of magnesium sulfate; potassium sulfate; sodium sulfate. The absorption of iron may be reduced by chelation with magnesium sulfate.
Potassium Phosphate: (Moderate) It has been reported that high intakes of phosphates, such as are found in dietary supplements or food additives, can interfere with absorption of trace nutrients such as iron, copper, and zinc. The magnitude of the effect may be small, and the interactions require further study to judge clinical significance. The theorized mechanism is the formation of insoluble complexes within the gut. Until more data are available, it may be helpful to separate administration times of phosphates by as much as possible from the oral administration of iron (e.g., iron salts or polysaccharide-iron complex), copper salts, or zinc salts to limit any potential interactions.
Potassium Phosphate; Sodium Phosphate: (Moderate) It has been reported that high intakes of phosphates, such as are found in dietary supplements or food additives, can interfere with absorption of trace nutrients such as iron, copper, and zinc. The magnitude of the effect may be small, and the interactions require further study to judge clinical significance. The theorized mechanism is the formation of insoluble complexes within the gut. Until more data are available, it may be helpful to separate administration times of phosphates by as much as possible from the oral administration of iron (e.g., iron salts or polysaccharide-iron complex), copper salts, or zinc salts to limit any potential interactions.
Proton pump inhibitors: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Rabeprazole: (Moderate) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of proton pump inhibitors can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. Proton pump inhibitors have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Ranitidine: (Minor) The bioavailability of oral iron salts is influenced by gastric pH, and the concomitant administration of H2-blockers can decrease iron absorption. The non-heme ferric form of iron needs an acidic intragastric pH to be reduced to ferrous and to be absorbed. Iron salts and polysaccharide-iron complex provide non-heme iron. H2-blockers have long-lasting effects on the secretion of gastric acid and thus, increase the pH of the stomach. The increase in intragastric pH can interfere with the absorption of iron salts.
Risedronate: (Moderate) Separate administration of oral risedronate and iron supplements by at least 2 hours. Iron will interfere with the absorption of oral risedronate.
Sarecycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Sodium Bicarbonate: (Moderate) Doses of antacids and iron should be taken as far apart as possible to minimize the potential for interaction. Antacids may decrease the absorption of oral iron preparations. At higher pH values, iron is more readily ionized to its ferric state and is more poorly absorbed.
Sodium picosulfate; Magnesium oxide; Anhydrous citric acid: (Moderate) Iron salts may chelate with the magnesium in sodium picosulfate; magnesium oxide; anhydrous citric acid solution. Therefore, products containing iron should be taken at least 2 hours before and not less than 6 hours after the administration of sodium picosulfate; magnesium oxide; anhydrous citric acid solution.
Tetracycline: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Tetracyclines: (Moderate) Separate administration of tetracyclines and iron by 2 to 3 hours. Iron may decrease the oral bioavailability of tetracyclines.
Thyroid hormones: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after the ingestion of iron supplements. Oral iron salts have been reported to chelate oral thyroid hormones within the GI tract when administered simultaneously, leading to decreased oral absorption of the thyroid hormone. For example, ferrous sulfate likely forms a ferric-thyroxine complex.
Vonoprazan: (Moderate) Monitor for decreased efficacy of oral iron salts if coadministered with vonoprazan. Vonoprazan reduces intragastric acidity, which may decrease the absorption of iron reducing its efficacy.
Vonoprazan; Amoxicillin: (Moderate) Monitor for decreased efficacy of oral iron salts if coadministered with vonoprazan. Vonoprazan reduces intragastric acidity, which may decrease the absorption of iron reducing its efficacy.
Vonoprazan; Amoxicillin; Clarithromycin: (Moderate) Monitor for decreased efficacy of oral iron salts if coadministered with vonoprazan. Vonoprazan reduces intragastric acidity, which may decrease the absorption of iron reducing its efficacy.
Zinc Salts: (Moderate) Orally administered zinc salts compete with iron supplements for absorption from the intestine. To minimize the interaction, separate oral iron and zinc doses by at least 2 hours. The oral receipt of 100 mg of iron as ferrous gluconate with 12 mg zinc in 11 patients with normal iron status and comparable total exchangeable zinc pools yielded a mean zinc absorption of 26.4% +/- 14.4% of the administered dose as compared with 44.5% +/- 22.5% of the dose given without concomitant iron. Concomitant use of iron 400 mg as ferrous gluconate yielded a mean zinc absorption of 22.9% +/- 6.4% of the zinc dose.
Zinc: (Moderate) Orally administered zinc salts compete with iron supplements for absorption from the intestine. To minimize the interaction, separate oral iron and zinc doses by at least 2 hours. The oral receipt of 100 mg of iron as ferrous gluconate with 12 mg zinc in 11 patients with normal iron status and comparable total exchangeable zinc pools yielded a mean zinc absorption of 26.4% +/- 14.4% of the administered dose as compared with 44.5% +/- 22.5% of the dose given without concomitant iron. Concomitant use of iron 400 mg as ferrous gluconate yielded a mean zinc absorption of 22.9% +/- 6.4% of the zinc dose.
Ferric maltol delivers iron for uptake across the intestinal wall and transfers to transferrin and ferritin. Ferric maltol has been shown to increase serum iron parameters, including ferritin and transferrin saturation (TSAT).
Normal erythropoiesis is dependent on the concentration of iron and erythropoietin available in the plasma. Approximately two-thirds of total body iron is in the circulating erythrocytes as hemoglobin, the major factor in oxygen transport to the tissues. Stored iron, in the form of ferritin and hemosiderin, accumulates during periods of positive iron balance and can be mobilized to meet iron requirements when iron intake is low. Administration of iron does not stimulate the production of red blood cells, nor does it correct abnormalities not caused by iron deficiency. A therapeutic response to treatment with iron products is dependent on the patient's ability to absorb and use the iron. The response to iron therapy is also influenced by the cause of the deficiency as well as other illnesses that can affect normal erythropoiesis. A positive response to iron treatment can be noted by an increase in the hemoglobin concentration by 1 g/dL or more 4 weeks after initiating oral therapy, assuming that transfusion or other interventions cannot explain the improvements in the patients clinical status.
Iron-containing proteins and enzymes are important in oxidation-reduction reactions, especially those of the mitochondria. Iron is a component of iron-containing heme proteins (e.g., hemoglobin, myoglobin), iron-sulfur enzymes (e.g., flavoproteins), proteins for iron storage and transport (e.g., transferrin) and other iron-containing enzymes. Iron deficiency not only causes anemia and decreased oxygen delivery, but it also reduces the metabolism of muscle and decreases mitochondrial activity. Thus, iron is important to several metabolic functions which are independent of its importance to erythropoiesis.
Ferric maltol is administered orally. It dissociates upon intake from the gastrointestinal tract, allowing iron and maltol to be absorbed separately. Maltol is metabolized through glucuronidation (UGT1A6) and sulphation in vitro. Of the total maltol ingested, a mean of between 40% and 60% is excreted in the urine as maltol glucuronide. Total serum iron concentrations increase in a less than dose-proportional manner with increasing ferric maltol doses.
Affected cytochrome P450 isoenzymes: none
-Route-Specific Pharmacokinetics
Oral Route
Total serum iron peak concentrations were achieved 1.5 to 3 hours after administration of ferric maltol and were comparable between day 1 and 8 in pharmacokinetic studies. Food has been shown to decrease the bioavailability of iron after ferric maltol administration.
-Special Populations
Renal Impairment
There was no clinically significant change in exposure of maltol or maltol glucuronide in subjects with non-dialysis dependent chronic kidney disease (eGFR of 16 to 59 mL/minute/1.73 m2).