Skip to Content

Ferrous sulfate / folic acid Disease Interactions

There are 4 disease interactions with ferrous sulfate / folic acid:


Ferrous Salts (Includes Ferrous sulfate/folic acid) ↔ Hemoglobin Abnormalities

Severe Potential Hazard, High plausibility

Applies to: Hemoglobinopathy, Blood Transfusion

There is no excretory mechanism for iron. Iron will correct only hemoglobin abnormalities due to iron deficiency and should not be used to treat conditions such as thalassemia, hemosiderosis, hemochromatosis, normocytic anemia (unless iron deficiency exists), or in patients receiving blood transfusions. Clinical monitoring of erythropoietic function and ferritin levels is recommended.


  1. "Product Information. INFeD (iron dextran)." Schein Pharmaceuticals Inc, Florham Park, NJ.

Folic Acid (Includes Ferrous sulfate/folic acid) ↔ Anemia

Severe Potential Hazard, High plausibility

Applies to: Anemia of Unspecified Nutritional Deficiency

The use of folic acid is contraindicated in patients with undiagnosed anemia. Folic acid in dosages above 1 mg/day can obscure the diagnosis of pernicious anemia by alleviating the hematologic abnormalities while allowing the progression of neurologic complications. In addition, folic acid alone is improper therapy in the treatment of pernicious anemia and other megaloblastic anemias where vitamin B12 is deficient.


  1. Butterworth CE Jr, Tamura T "Folic acid safety and toxicity: a brief review." Am J Clin Nutr 50 (1989): 353-8
  2. Katz M "Potential danger of self-medication with folic acid." N Engl J Med 289 (1973): 1095
  3. "Product Information. Renal Multivitamin Formula Rx (folic acid)." Vitaline Corporation, Ashland, OR.

Ferrous Salts (Includes Ferrous sulfate/folic acid) ↔ Achlorhydria

Moderate Potential Hazard, Moderate plausibility

Applies to: Achlorhydria

Gastric acidity increases iron bioavailability by maintaining the ingested iron in a reduced form as ferrous ions, which are more readily absorbed than ferric ions. Therefore, when iron therapy is administered orally, higher dosages may be necessary for patients with decreased gastric acid production. Also, a liquid formulation is recommended in these patients because dissolution of the tablet coating depends on normal gastric acidity.


  1. "Product Information. Feosol Tablets (ferrous sulfate)." SmithKline Beecham, Philadelphia, PA.

Ferrous Salts (Includes Ferrous sulfate/folic acid) ↔ Gastrointestinal Irritation

Moderate Potential Hazard, High plausibility

Applies to: Colitis/Enteritis (Noninfectious), Peptic Ulcer

Iron can be irritating and damaging to gastrointestinal mucosa. Iron therapy should be administered cautiously in patients with peptic ulcer disease, enteritis, or ulcerative colitis.


  1. "Product Information. Feosol Tablets (ferrous sulfate)." SmithKline Beecham, Philadelphia, PA.

ferrous sulfate / folic acid drug Interactions

There are 174 drug interactions with ferrous sulfate / folic acid

ferrous sulfate / folic acid alcohol/food Interactions

There is 1 alcohol/food interaction with ferrous sulfate / folic acid

Drug Interaction Classification

The classifications below are a general guideline only. It is difficult to determine the relevance of a particular drug interaction to any individual given the large number of variables.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No information available.

Do not stop taking any medications without consulting your healthcare provider.

Disclaimer: Every effort has been made to ensure that the information provided by Multum is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. Multum's information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill, knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2018 Multum Information Services, Inc. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.