Ferric maltol

Ferric maltol has not been studied in patients with impaired renal (eGFR<15 ml/min/1.73 m²) and/or impaired hepatic function.

Absorption of oral iron may be reduced by calcium and magnesium salts (such as magnesium trisilicate). Administration of iron preparations with such compounds should be separated by at least 2 hours.

Concomitant administration of ferric maltol and intravenous iron should be avoided as the combination may induce hypotension or even collapse due to the fast release of iron resulting from saturation of transferrin caused by intravenous iron.

Absorption of both iron and antibiotic may be reduced if oral iron is given with tetracycline. Administration of iron preparations and tetracyclines should be separated by 2 to 3 hours.

Concomitant use of chloramphenicol with iron should be avoided as chloramphenicol delays plasma iron clearance, incorporation of iron into red blood cells and interferes with erythropoiesis.

Concomitant use of iron with dimercaprol should be avoided as the combination of dimercaprol and iron is nephrotoxic.

Concomitant use of iron with methyldopa should be avoided as oral iron may antagonise the hypotensive effect of methyldopa.

Oral iron is known to reduce the absorption of penicillamine, bisphosphonates, ciprofloxacin, entacapone, levodopa, levofloxacin, levothyroxine (thyroxine), moxifloxacin, mycophenolate, norfloxacin and ofloxacin. These medicinal products should be given at least 2 hours apart from ferric maltol.

Ferric maltol should not be used in patients with inflammatory bowel disease (IBD) flare or in IBD-patients with haemoglobin (Hb) <9.5 g/dl.

Food has been shown to inhibit uptake of ferric maltol: Ferric maltol should be taken on an empty stomach.

There are no data from the use of ferric maltol in pregnant women. Ferric maltol is not systemically available.

Definitive animal studies are not available for maltol with respect to reproductive toxicity. As a precautionary measure, it is preferable to avoid the use of ferric maltol during pregnancy.

Ferric maltol is not available systemically and is therefore unlikely to pass into the mother’s milk. No clinical studies are available to date. As a precautionary measure, it is preferable to avoid the use of ferric maltol during breast-feeding.

Fertility

There are no data on the effect of ferric maltol on human fertility. Ferric maltol is not systemically available. Fertility was unaffected following maltol treatment in animal studies. However, the conducted reproductive toxicity studies are insufficient to discard any risk in humans.

No effect is expected from an oral iron product.

Summary of the safety profile

The most frequently reported adverse reactions were gastrointestinal symptoms (abdominal pain [8%], flatulence [4%], constipation [4%], abdominal discomfort [2%]/distension [2%] and diarrhoea [3%]) and these were mainly mild to moderate in severity. Reported severe adverse reactions were abdominal pain [4%], constipation [0.9%] and diarrhoea [0.9%].

List of adverse reactions

The following list presents all adverse reactions occurring clinical studies to date with ferric maltol.

Adverse reaction frequencies are defined as: very common (≥1/10), common (≥1/100, <1/10), uncommon (≥1/1,000, <1/100), rare (≥1/10,000, <1/1,000) or very rare (<1/10000).

Adverse reactions observed during clinical studies to date:

Nervous system disorders

Uncommon: Headache

Gastrointestinal disorders

Common: Abdominal pain (including upper abdomen), Flatulence, Constipation, Abdominal discomfort/distension, Diarrhoea, Nausea

Uncommon: Small intestinal bacterial overgrowth, Vomiting

Skin and subcutaneous tissue disorders

Uncommon: Acne, Erythema

Musculoskeletal and connective tissue disorders

Uncommon: Joint stiffness, Pain in extremity

General disorders and administration site conditions

Uncommon: Thirst

Investigations

Blood alkaline phosphatase increased, Blood thyroid stimulating hormone increased, Gamma-glutamyltransferase increased