Ferrous Sulfate

ATC code

B03AA07

Therapeutic class

Antianemic · Bivalent iron, oral preparation

Forms

extended-release tablet, oral tablet, oral solution, oral drops

Brand names

Tardyferon (ES) · Feosol (US) · Fer-In-Sol (US) · Timoferol (FR)

Overall confidence

medium

Regulatory sources consulted

AEMPS-CIMA-52994
AEMPS CIMA · nº registro 52994 ↗

Approved indications

Treatment of iron deficiency anemia and prophylaxis of iron deficiency states (e.g., pregnancy, lactation, rapid growth period, etc.) when dietary intake is inadequate.

Contraindications

Absolute

Iron overload (e.g., hemochromatosis, chronic hemosiderosis).
Anemias not caused by iron deficiency (e.g., megaloblastic anemia due to vitamin B12 deficiency, hemolytic anemias).
Hypersensitivity to ferrous sulfate or any of the excipients.

Clinical warnings

Boxed warning · Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6. Keep this product out of reach of children. — Clinical Practice
Risk of mouth ulceration and tooth discoloration with immediate-release tablets if chewed or kept in the mouth. Swallow whole with water. — AEMPS CIMA

Drug interactions

HighTetracyclinesJ01AA
Mechanism: Iron forms insoluble complexes (chelates) with tetracyclines in the gastrointestinal tract, decreasing the absorption of both drugs.
Recommendation: Administer ferrous sulfate at least 2 hours before or 3 hours after the tetracycline dose.
AEMPS CIMA
ModerateLevothyroxineH03AA01
Mechanism: Ferrous sulfate reduces the absorption of levothyroxine, potentially decreasing its efficacy.
Recommendation: Administer levothyroxine at least 4 hours before or 4 hours after ferrous sulfate administration.
AEMPS CIMA
ModerateAntacidsA02A
Mechanism: Antacids containing magnesium, aluminum, or calcium salts can decrease iron absorption by increasing gastric pH and forming complexes.
Recommendation: Administer ferrous sulfate at least 2 hours before or 2 hours after taking the antacid.
AEMPS CIMA

Adverse events

Common (≥1%)

constipation · diarrhea · abdominal distension · abdominal pain · nausea · black stools

Rare but serious

anaphylactic reaction · gastrointestinal melanosis · iron poisoning (overdose)

Pregnancy and lactation

FDA category: Not Assigned

Pregnancy: May be used if clinically indicated. Lactation: No effects on the breastfed newborn/infant are anticipated. May be used during breastfeeding.