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Clinician’s Corner: IRON SUPPLEMENTATION

Let’s discuss another very common element, which approximately 14% to 18% of Americans supplement their diets with. Iron is a mineral that is naturally present in many foods, used to fortify some food products, and available as a dietary supplement. Iron is an essential component of hemoglobin, a red blood cell protein that transfers oxygen from the lungs to the tissues. Iron is also in myoglobin, a protein that provides oxygen to muscles, iron also supports metabolism. Iron is also needed for growth, development, normal cellular functioning, and synthesis of some hormones and connective tissue

Sources: The richest sources of iron in the diet include lean meat and seafood (about 15% of Western diet). Non-meat sources of iron include nuts, beans, vegetables, and grain products that are fortified (about 85%).

Correction of iron deficiency:

  • Oral: only 10% of an oral iron dose is absorbed in patients with normal iron stores.
  • 20% to 30% of oral iron dose is absorbed in persons with inadequate iron stores
  • May take up to 4 months for iron stores to return to normal with supplements
  • Ferrous sulfate 325mg by mouth three times daily is the most common form.
    • Start with one tablet at bedtime on empty stomach, may increase 1 tablet every week.
    • Take 1 or 2 hours before a meal because food can decrease absorption by 50%.
    • If stomach upset occurs, may take with small snack such as crackers. NO milk or tea.
  • Extended-release or enteric-coated formulations bypass the area of maximal absorption in the intestines.
  • Orange juice (Vitamin-C) can double the absorption. About 200 mg is needed to increase absorption of 30 mg of elemental iron.
  • Take 1 hour before or 3 hours after antacids. Food decreases absorption. Proton Pump inhibitors (Prilosec), Histamine-2 Receptor blockers (Zantac) will impair iron absorption.
  • If constipation occurs initiate stool softener with docusate (Colace®) 100mg one daily

Iron-Drug Interactions: This does not mean that you can’t take these  drugs while taking iron.  Consult your Thompson Pharmacist for strategies to help minimize the impact of iron therapy on these drugs.

  • Fluoroquinolones -antibiotics like Cipro and Levaquin
  • Tetracycline and Doxycycline
  • Digoxin
  • Carbidopa/levodopa (Sinemet, Stalevo)
  • Levothyroxine (AVOID iron by 4 hours!)  – this is the most important iron :drug interaction

Most common side effects:

Metallic taste, constipation, nausea, diarrhea, dark stools, and abdominal pain

EXTREMELY IMPORTANT: Insist on child resistant packaging if there is ANY chance small children may be in the home. Iron is still the #1 cause of pediatric fatalities due to toxicity. Before the mandatory child resistant packaging, iron overdose accounted for 1/3 of pediatric poisonings.

Patient groups most likely to need iron supplementation

  • Pregnant women
  • Infants and young children
  • Women with heavy menstrual bleeding
  • Frequent blood donors
  • Patients with cancer
  • Patients with gastric disorders (gastrectomy, weight loss surgery, ulcerative colitis, celiac disease)
  • Proton pump inhibitors
  • reduce absorption of non-heme iron.
  • ACE cough: iron might inhibit the dry cough associated with ACE inhibitors.

Your Thompson Pharmacist is a great resource to help you work around the drug interactions with iron.  Your Thompson Pharmacist wants you to get the most out of your iron supplements.  Remember at Thompson Pharmacy its all for you!