Corrigan Plus

Composition

Note: The brand "Corrigan" alludes to Corrigan's pulse, a historical medical eponym for the bounding pulse of aortic regurgitation / iron-deficiency anemia - an apt name for an iron supplement. "Corrigan Plus" is a branded formulation; its precise composition should be verified from the product label or prescriber information.

Drug Class

Mechanism of Action

• Iron (as ferrous/Fe²⁺ form) is directly absorbed in the duodenum and upper jejunum via DMT-1 transporters.
• Ascorbic acid (vitamin C, chelated to the iron) keeps iron in the soluble ferrous (Fe²⁺) state in the acidic stomach, improving bioavailability by at least 30% compared to standard ferrous salts.
• Iron is incorporated into hemoglobin in red blood cells, restoring oxygen-carrying capacity.
• Ferrous salts are absorbed approximately 3x better than ferric (Fe³⁺) salts (Goodman & Gilman's Pharmacological Basis of Therapeutics).

• Folate is converted to tetrahydrofolate (THF), a cofactor needed for DNA synthesis and red blood cell maturation.
• Prevents megaloblastic changes in developing RBCs, especially important in pregnancy.

Indications (Uses)

1. Iron-deficiency anemia - primary indication; low hemoglobin due to inadequate iron intake, chronic blood loss, or poor absorption
2. Anemia in pregnancy - widely prescribed in obstetrics for both iron and folate supplementation
3. Prophylaxis of neural tube defects - folic acid component prevents spina bifida and anencephaly when started pre-conception and in early pregnancy
4. Post-operative or post-hemorrhagic anemia - to replete iron stores after significant blood loss
5. Nutritional anemia - in vegetarians, adolescents, or those with poor dietary intake
6. Mixed deficiency anemia - when both iron and folate deficits coexist

Dosage

• Adults (including pregnant women): 1 tablet once or twice daily, preferably on an empty stomach or as directed by the physician
• For better absorption: Take 30-60 minutes before meals; vitamin C in the formulation already aids absorption
• If GI intolerance occurs: Can be taken with food, though this slightly reduces absorption

Side Effects

• Nausea, heartburn, upper gastric discomfort
• Constipation or diarrhea
• Dark/black stools (harmless - due to iron)
• Metallic taste

• Vomiting
• Abdominal cramps

• Start with lower doses and titrate up
• Take with a small snack if GI intolerance is problematic
• Drink adequate fluids to reduce constipation

Contraindications

• Hemochromatosis or other iron-overload conditions (e.g., hemosiderosis)
• Hemolytic anemia (without documented iron deficiency)
• Allergy to any component
• Conditions where folate supplementation may mask vitamin B12 deficiency (e.g., pernicious anemia - use with caution)

Drug Interactions

Special Populations

• Pregnancy: Recommended and safe; in fact, widely prescribed as the first-line anemia supplement in antenatal care
• Breastfeeding: Generally considered safe
• Children (under 12): Use only on medical advice; dose adjustment needed
• Renal/hepatic impairment: Use with caution; consult physician

Key Advantage Over Standard Iron Tablets