Iron Supplements Side Effects, Uses, Dosage, and Interactions

Ferrous sulfate is used for the treatment and prevention of iron-deficiency anemias.

Iron supplements are available over-the-counter (OTC) in generic form. Other names for ferrous sulfate are the brand names Fer-In-Sol, Slow Fe, Feosol, Feratab, and many more.

The most common side effects associated with ferrous sulfate treatment are:

1. constipation,
2. dark stools,
3. stomach pain,
4. nausea, and
5. vomiting.

Less common side effects include:

1. diarrhea,
2. heartburn, and
3. urine discoloration.

The recommended dietary reference intake (RDA) based on elemental iron is:

• Individuals 19-50 years : Males 8 mg/day, Females 18 mg/day,
• Pregnant women: 27 mg/day,
• Breastfeeding women: 9 mg/day.
• Individuals = 50 years: 8 mg/day
• For treatment of anemia, the recommended dose expressed as ferrous sulfate is 300 mg every 12 hours and may be increased to 300 mg every 6 hours (regular tablets) or 250 mg daily or every 12 hours (extended release tablets).
• The dose for preventing iron deficiency anemia is 300 mg once daily of ferrous sulfate.

Iron supplements are available as preparations of:

• Elixir: 220 mg/5 ml;
• Solution 75 mg/ml;
• Syrup: 300 mg/5 ml;
• Tablets: 325 mg;
• Delayed release tablets: 324, 325 mg;
• Extended release tablets: 160, 142 mg.

Iron Supplements should be stored at room temperature, 15 C-30 C (59 F-86 F).

Antacids, H2-antagonists (for example, cimetidine, ranitidine, famotidine, or nizatidine), pancrelipase, and proton pump inhibitors (for example, omeprazole, lansoprazole, raberprazole, pantoprazole, or esomeprazole) may decrease the absorption of iron supplements.

Iron salts may decrease the blood concentration of bisphophonates (for example, aldendronate, etidronate, risedronate, or tiludronate), cefdinir (Omnicef), deferiprone (Ferripox), dolutegravir (Tivicay), eltrombopag (Promacta), levothyroxine (Synthroid), quinolone antibiotics (for example, ciprofloxacin, levofloxacin), and tetracycline antibiotics.

• Ferrous sulfate crosses the placenta and is safe to use during pregnancy. All pregnant females should be screened for iron deficiency anemia and treated as necessary.
• Iron is normally found in breast milk. Ferrous sulfate is secreted into breast milk.