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Ferrous Gluconate

Generic Name

ferrous gluconate


Trade Name

Fergon(320 mg.)
Fergon is also available as an Elixir.
This drug is available in a generic form.


What is ferrous gluconate?

This preparation contains the mineral, iron, which is necessary for the formation and function of red blood cells. It is these cells that carry oxygen through the blood stream. In tiny amounts, the mineral is also necessary for the chemical functioning of many of the bodies’ cells.


What is it used for?

Iron should only be taken for very specific reasons and only under a physician’s direction.

These reasons are as follows:

  • Iron deficiency anemia. Anemia means a low red blood cell count. An anemia may be due to lack of iron in the diet, blood loss in the intestinal tract or excessive menstrual flow
  • Pregnancy

Except for these two reasons, do not take iron, even the small amount in a daily vitamin-mineral pill unless advised by a physician.


How do I take it?

Follow your physician’s instructions carefully. The best absorption occurs when taken on an empty stomach, but these products may be taken with meals to avoid stomach upset. Keep in a tightly sealed container. Protect this medication from excess moisture and heat. Do not freeze the elixir. Liquid forms should be diluted and sipped through a straw into the back of the mouth to prevent tooth discoloration. Keep all medications away from children. Never share your medications with anyone else.


What do I do for a missed dose?

If you miss a dose of this medicine, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and return to your regular schedule. Do not double up on this medication.


Are there interactions with food or beverages?

Coffee, tea, eggs and milk may prevent the full absorption of iron. However, absorption is enhanced by vitamin C. Fiber or bran may also reduce absorption but may be helpful to correct the constipation or diarrhea that iron may cause. Do not take this medication at the same time as oral calcium supplements.


Are there interactions with other drugs?

An interaction generally means that one drug may increase or decrease the effect of another drug. Also, the more medications a person takes, the more likely there will be a drug interaction.

Interactions with this drug may occur with the following:

  • antacids
  • penicillamine (Cuprimine, Depen)
  • levodopa (Dopar, Larodopa)
  • methyldopa (Aldomet)
  • quinolone antibiotics (Cipro, Floxin)
  • cimetidine (Tagamet)
  • tetracycline antibiotic (Achromycin)

Sometimes a simple adjustment, like staggering doses by 2 hours, is sufficient to avoid problems, but always check with your physician.


Is there a problem if I have another disorder or disease?

At times, a drug may have a different or enhanced effect when other diseases are present. At other times, the drug may worsen or effect another disease.

With this drug, the following disorders may be a problem:

  • Hemochromatosis
  • Hemosiderosis
  • Hemolytic anemia


What about allergies?

People who have known allergies or asthma may be at an increased risk for a reaction from any new medication. The physician should always know a patient’s allergy history. Signs of an allergic reaction are skin rash, hives and itching. Of course, a person should not take ferrous gluconate if there has been a previous reaction to this or a similar drug.


What if I’m pregnant, considering pregnancy or breast-feeding?

Most females now know that, if possible, no drug, including alcohol, should be taken during pregnancy or lactation. The potential danger, of course, is an injury to the baby. However, some drugs are much safer than others in this regard. So, the FDA has a grading system for each drug which reflects what is known medically. It ranks drugs from A, where medical studies show no evidence for danger to the fetus or mother, to B, C, D and X, where the medical evidence indicates that the risk to the fetus outweighs any benefit to the mother. Ferrous gluconate is not ranked. However, the pregnant female needs additional iron for her baby. The amount and frequency of iron supplementation should be discussed with your physician. Always consult your physician before taking any drug during or when planning pregnancy.


What are the effects on sexual function?

There are no known adverse effects of ferrous gluconate on sexual function.


Are there other precautions?

Iron supplements will cause a black stool which is harmless. They also have a tendency to cause constipation, diarrhea or abdominal discomfort. The gluconate form of iron is better tolerated than ferrous sulfate and may have a lower incidence of GI side effects.


How long is it safe to take ferrous gluconate?

The length of oral iron therapy is usually determined by the success in discovering the underlying cause of the anemia. Once the cause is determined and treated, it takes approximately 4 to 6 months for iron therapy to reverse anemias. The iron supplement should then be discontinued to prevent iron build up in the body. Long-term use should always be with physician supervision.


How about side effects?

Adverse reactions can occur with any drug, even over-the-counter medications. Some of these are mild such as a stomach upset, which may be avoided by taking the medication with food. Minor reactions may go away on their own but if they persist, contact the physician. For major reactions, the patient should contact the physician immediately.

For ferrous gluconate, the following are the observed side effects:


  • heartburn
  • nausea
  • vomiting
  • constipation
  • diarrhea
  • black stools


  • stomach pain or cramping
  • bloody stools


A physician’s comment…

Oral iron therapy is usually effective in treating iron deficiency anemia. However, the cause of this type of anemia should always be known. Bleeding peptic ulcers and colon cancer are two causes of this type of anemia. As noted above, oral iron should not be taken when the anemia is corrected and generally is not used to prevent such anemias. It is always critical to know and correct the underlying cause. Furthermore, since the body cannot rid itself of iron and since excessive amounts of iron are damaging to the body, the drug should not be taken long-term without approval from the physician. This means you should not even take iron as part of a vitamin-mineral formula unless there is a specific reason to do so. Simply feeling tired or fatigued is not a good reason.