Pharmacology
Mechanism of Action
Ferric maltol delivers iron for uptake across the intestinal wall and transfer to transferrin and ferritin. Replaces iron, found in hemoglobin, myoglobin, and other enzymes; allows the transportation of oxygen via hemoglobin.
Pharmacokinetics/Pharmacodynamics
Absorption
Ferric maltol dissociates upon uptake from the GI tract; iron and maltol are absorbed separately.
Metabolism
Maltol: Rapidly conjugated with glucuronic acid.
Excretion
Maltol: Urine (~40% to 60% as maltol glucuronide).
Time to Peak
Iron: 1.5 to 3 hours.
Use: Labeled Indications
Iron deficiency: Treatment of iron deficiency in adults.
Contraindications
Hypersensitivity to ferric maltol or any component of the formulation; hemochromatosis and other iron overload syndromes; patients receiving repeated blood transfusions.
Dosage and Administration
Dosing: Adult
Note: Dose expressed in terms of elemental iron; each ferric maltol capsule contains 30 mg of elemental iron.
Iron deficiency, treatment: Oral: 30 mg twice daily.
Dosing: Geriatric
Refer to adult dosing.
Administration
Oral: Administer ≥1 hour before or 2 hours after a meal. Swallow whole; do not open, break, or chew.
Storage
Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Iron is a leading cause of fatal poisoning in children. Store out of children's reach and in child-resistant containers.
Drug Interactions
Alpha-Lipoic Acid: Iron Preparations may decrease the absorption of Alpha-Lipoic Acid. Alpha-Lipoic Acid may decrease the absorption of Iron Preparations. Consider therapy modification
Antacids: May decrease the absorption of Iron Preparations. Management: Separate dosing of oral iron preparations and antacids as much as possible to avoid decreased efficacy of iron preparation. If coadministered with antacids, monitor for decreased therapeutic effects of iron preparations. Consider therapy modification
Baloxavir Marboxil: Polyvalent Cation Containing Products may decrease the serum concentration of Baloxavir Marboxil. Avoid combination
Bictegravir: Iron Preparations may decrease the serum concentration of Bictegravir. Management: Bictegravir, emtricitabine, and tenofovir alafenamide can be administered with iron preparations under fed conditions, but coadministration with or 2 hours after an iron preparation is not recommended under fasting conditions. Consider therapy modification
Bisphosphonate Derivatives: Polyvalent Cation Containing Products may decrease the serum concentration of Bisphosphonate Derivatives. Management: Avoid administration of oral medications containing polyvalent cations within: 2 hours before or after tiludronate/clodronate/etidronate; 60 minutes after oral ibandronate; or 30 minutes after alendronate/risedronate. Exceptions: Pamidronate; Zoledronic Acid. Consider therapy modification
Cefdinir: Iron Preparations may decrease the serum concentration of Cefdinir. Red-appearing, non-bloody stools may also develop due to the formation of an insoluble iron-cefdinir complex. Management: Avoid concurrent cefdinir and oral iron when possible. Separating doses by several hours may minimize interaction. Iron-containing infant formulas do not appear to interact with cefdinir. Consider therapy modification
Deferiprone: Polyvalent Cation Containing Products may decrease the serum concentration of Deferiprone. Management: Separate administration of deferiprone and oral medications or supplements that contain polyvalent cations by at least 4 hours. Consider therapy modification
Dimercaprol: May enhance the nephrotoxic effect of Iron Preparations. Avoid combination
Dolutegravir: Iron Preparations may decrease the serum concentration of Dolutegravir. Management: Administer dolutegravir at least 2 hours before or 6 hours after oral iron. Administer dolutegravir/rilpivirine at least 4 hours before or 6 hours after oral iron. Alternatively, dolutegravir and oral iron can be taken together with food. Consider therapy modification
Eltrombopag: Polyvalent Cation Containing Products may decrease the serum concentration of Eltrombopag. Management: Administer eltrombopag at least 2 hours before or 4 hours after oral administration of any polyvalent cation containing product. Consider therapy modification
Entacapone: Iron Preparations may decrease the serum concentration of Entacapone. Management: Consider separating doses of the agents by 2 or more hours to minimize the effects of this interaction. Monitor for decreased therapeutic effects of levodopa during concomitant therapy, particularly if doses cannot be separated. Consider therapy modification
Ferric Hydroxide Polymaltose Complex: May decrease the serum concentration of Iron Preparations. Specifically, the absorption of oral iron salts may be reduced. Management: Do not administer intravenous (IV) ferric hydroxide polymaltose complex with other oral iron preparations. Therapy with oral iron preparations should begin 1 week after the last dose of IV ferric hydroxide polymaltose complex. Consider therapy modification
Histamine H2 Receptor Antagonists: May decrease the absorption of Iron Preparations. Monitor therapy
Levodopa: Iron Preparations may decrease the serum concentration of Levodopa. Only applies to oral iron preparations. Management: Consider separating doses of the agents by 2 or more hours to minimize the effects of this interaction. Monitor for decreased therapeutic effects of levodopa during concomitant therapy, particularly if doses cannot be separated. Consider therapy modification
Levothyroxine: Iron Preparations may decrease the serum concentration of Levothyroxine. Management: Separate oral administration of iron preparations and levothyroxine by at least 4 hours. Separation of doses is not required with parenterally administered iron preparations or levothyroxine. Consider therapy modification
Methyldopa: Iron Preparations may decrease the serum concentration of Methyldopa. Consider therapy modification
PenicillAMINE: Polyvalent Cation Containing Products may decrease the serum concentration of PenicillAMINE. Management: Separate the administration of penicillamine and oral polyvalent cation containing products by at least 1 hour. Consider therapy modification
Phosphate Supplements: Iron Preparations may decrease the absorption of Phosphate Supplements. Management: Administer oral phosphate supplements as far apart from the administration of an oral iron preparation as possible to minimize the significance of this interaction. Exceptions: Sodium Glycerophosphate Pentahydrate. Consider therapy modification
Proton Pump Inhibitors: May decrease the absorption of Iron Preparations. Monitor therapy
Quinolones: Iron Preparations may decrease the serum concentration of Quinolones. Management: Give oral quinolones at least several hours before (4 h for moxi- and sparfloxacin, 2 h for others) or after (8 h for moxi-, 6 h for cipro/dela-, 4 h for lome-, 3 h for gemi-, and 2 h for levo-, nor-, oflox-, pefloxacin, or nalidixic acid) oral iron. Exceptions: LevoFLOXacin (Oral Inhalation). Consider therapy modification
Raltegravir: Polyvalent Cation Containing Products may decrease the serum concentration of Raltegravir. Management: Administer raltegravir 2 hours before or 6 hours after administration of the polyvalent cations. Dose separation may not adequately minimize the significance of this interaction. Consider therapy modification
Tetracyclines: May decrease the absorption of Iron Preparations. Iron Preparations may decrease the serum concentration of Tetracyclines. Management: Avoid this combination if possible. Administer oral iron preparations at least 2 hours before, or 4 hours after, the dose of the oral tetracycline derivative. Monitor for decreased therapeutic effect of oral tetracycline derivatives. Exceptions: Eravacycline. Consider therapy modification
Trientine: Polyvalent Cation Containing Products may decrease the serum concentration of Trientine. Management: Avoid concomitant administration of trientine and oral products that contain polyvalent cations. If oral iron supplements are required, separate the administration by 2 hours. If other oral polyvalent cations are needed, separate administration by 1 hour. Consider therapy modification
Adverse Reactions
1% to 10%:
Gastrointestinal: Flatulence (5%), constipation (4%), diarrhea (4%), fecal discoloration (4%), abdominal pain (3%), nausea (2%), vomiting (2%), abdominal distention (1%), abdominal distress (1%)
Warnings/Precautions
Concerns related to adverse effects:
- Iron overload: Excessive iron therapy can lead to iron overload and possibly iatrogenic hemosiderosis. Assess iron parameters prior to and during therapy; do not use in patients with iron overload or receiving IV iron therapy.
Disease-related concerns:
- Inflammatory bowel disease: Avoid use in patients with an active inflammatory bowel disease flare; may increase risk of GI tract inflammation.
Concurrent drug therapy issues:
- Altered medication absorption: May affect absorption of other medications. The manufacturer's labeling recommends separating the administration of ferric maltol and other oral medications where reductions in bioavailability may affect safety and effectiveness by ≥4 hours.
- Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Special populations:
- Elderly: Anemia in elderly patients is often caused by "anemia of chronic disease" or associated with inflammation rather than blood loss. Iron stores are usually normal or increased, with a serum ferritin >50 ng/mL and a decreased total iron binding capacity. Hence, the "anemia of chronic disease" is not secondary to iron deficiency but the inability of the reticuloendothelial system to reclaim available iron stores.
- Pediatric: Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6 years of age. Keep this product out of the reach of children. In case of accidental overdose call the poison control center immediately.
Dosage form specific issues:
- Oral iron formulations: Immediate-release oral iron products are preferred for treatment of iron deficiency anemia; enteric-coated and slow/sustained-release preparations are not desired due to poor absorption (Hershko 2014; Liu 2012).
Other warnings/precautions:
- Duration of therapy: Administration of iron for >6 months should be avoided except in patients with continuous bleeding or menorrhagia.
Monitoring Parameters
Hemoglobin and hematocrit; consider additional tests such as RBC count, RBC indices, serum ferritin, transferrin saturation, total iron-binding capacity, serum iron concentration, and erythrocyte protoporphyrin concentration (CDC 1998).
Pregnancy
Pregnancy Considerations
Iron and maltol are absorbed separately following maternal ingestion; the fetus is not expected to be exposed to the ferric maltol complex.
Maternal iron requirements increase during pregnancy. Adequate iron concentrations to the fetus can be maintained regardless of maternal iron status, except in severe cases of anemia (IOM 2001). Untreated iron deficiency and iron deficiency anemia (IDA) in a pregnant female may be associated with adverse events, including low birth weight, preterm birth, or increased perinatal mortality (ACOG 95 2008; IOM 2001; Pavord 2012).
In general, treatment of iron deficiency or IDA in pregnancy is the same as in nonpregnant females. The majority of studies note iron therapy improves maternal hematologic parameters; however, information related to clinical outcomes in the mother and neonate is limited (Peña-Rosas 2015; Reveiz 2011; Siu 2015). Oral preparations are generally sufficient; however, parenteral iron therapy may be used in females who cannot tolerate or will not take oral iron, in cases of severe iron deficiency, or when malabsorption is present (ACOG 95 2008; Pavord 2012).
Patient Education
What is this drug used for?
- It is used to treat low iron levels.
Frequently reported side effects of this drug
- Passing gas
- Constipation
- Diarrhea
- Abdominal pain
- Nausea
- Vomiting
- Green stool discoloration
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
- Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.
Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
