Is It Safe To Take Iron And Warfarin Together?

The pharmacist discusses whether or not there is a drug interaction between warfarin and iron supplements.

Is It Safe To Take Iron And Warfarin Together?
May 10, 2019

fripps asked

I am on warfarin. Will it be okay to take iron supplements?

At a glance

  • There is no interaction between warfarin and iron supplements. They can be taken together (but iron supplementation should generally only be done if recommended by your doctor).


Iron Pills With Text- Taking With Warfarin

There is no interaction between iron supplements and warfarin. They are considered safe to take together.

It makes sense to be concerned about a potential interaction, seeing as to how iron supplements are commonly used for blood-related disorders, like anemia.

However, iron supplementation does not affect coagulation and doesn't affect warfarin (although low levels are associated with an increased risk of blood clots).[1]

Iron Supplementation

Iron is an essential (i.e. must be consumed) mineral which is widely utilized in the body. It is a component of hemoglobin, myoglobin, and many enzymes. When iron intake is inadequate, red blood cell counts drop (anemia) and a wide range of symptoms can occur.[2]

Iron-deficient anemia symptoms include:[3]

  • Fatigue
  • Shortness of breath
  • Increased heart rate
  • Paleness
  • Headache
  • Inflammation of the tongue
  • Nail misformation
  • Mental fogginess

It is important to note that iron generally should only be taken as a supplement when you don't get enough from your diet and has been recommended by your doctor.

Supplemental iron is beneficial in treating (and preventing) only certain types of anemia (iron-deficient anemia) and taking too much can cause significant side effects and toxicity.[4]

In order to determine if the iron supplementation will be beneficial, the type of anemia you have (or whether or not you are at risk of it) should be assessed.

Iron Interactions

While iron does not interact with warfarin, it does have several notable interactions with other drugs.

First and foremost, iron should generally be taken by itself since other drugs (and food) decrease its absorption. However, iron is notoriously poorly tolerated, often causing gastrointestinal distress in those taking it and causing symptoms such as stomach cramps and diarrhea.[5]

Additionally, iron can decrease the absorption of other drugs.

Perhaps most notably, it can reduce the absorption of:[6]

  • Bisphosphonates (e.g. Fosamax, Boniva)
  • Thyroid hormones (e.g. levothyroxine)
  • Tetracycline antibiotics (e.g. tetracycline, doxycycline)
  • Quinoline antibiotics (e.g. Levaquin)
  • Methyldopa
  • Levodopa

Be sure to discuss any potential interactions if you are prescribed iron therapy with your doctor and/or pharmacist

  1. ^ Low serum iron levels are associated with elevated plasma levels of coagulation factor VIII and pulmonary emboli/deep venous thromboses in replicate cohorts of patients with hereditary haemorrhagic telangiectasia. PubMed
  2. ^ Review on iron and its importance for human health. PubMed
  3. ^ Iron Deficiency Anemia: A Common and Curable Disease. PubMed
  4. ^ Management of Iron Deficiency Anemia. PubMed
  5. ^ Treatment of iron deficiency anemia associated with gastrointestinal tract diseases. PubMed
  6. ^ Iron supplements: a common cause of drug interactions. PubMed

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