Methylene Blue

Last updated on RxList: 6/29/2021
Methylene Blue Side Effects Center

What Is Methylene Blue?

Methylene Blue (methylene blue) injection is a form of hemoglobin, a substance in blood, used to treat methemoglobinemia. Methylene Blue oral is used to treat methemoglobinemia and urinary tract infections. Methylene Blue is also used as a dye or staining agent to make certain body fluids and tissues easier to view during surgery or on an x-ray or other diagnostic exam. Methylene Blue is available in generic form.

What Are Side Effects of Methylene Blue?

Common side effects of Methylene Blue include abnormal urine or stool color. Less frequent side effects of Methylene Blue include:

Side effects of large doses of Methylene Blue include chest pain and confusion.

Dosage for Methylene Blue

Methylene Blue is dosed 0.045 to 0.09 mL per pound of body weight.

What Drugs, Substances, or Supplements Interact with Methylene Blue?

Methylene Blue may interact with acetazolamide, antacids, sodium bicarbonate, or diuretics (water pills). Tell your doctor all medications you are taking.

Methylene Blue During Pregnancy or Breastfeeding

Methylene blue may cause harm to a fetus, but the medication may sometimes be used during pregnancy. Your doctor will determine whether or not this medication is safe. Tell your doctor if you are pregnant. It is not known whether Methylene Blue passes into breast milk or if it could harm a nursing baby. Consult your doctor before breastfeeding.

Additional Information

Our Methylene Blue (methylene blue injection) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Methylene Blue Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your caregivers right away if you have:

  • confusion or weakness;
  • pale or yellowed skin;
  • dark colored urine;
  • fever; or
  • high levels of serotonin in the body--agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting.

Common side effects may include:

  • pain in your arms or legs;
  • blue or green urine;
  • altered sense of taste;
  • headache, dizziness;
  • sweating, skin discoloration;
  • nausea; or
  • feeling hot.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Methylene Blue (Methylene Blue Injection)


Digestive Disorders: Common Misconceptions See Slideshow
Methylene Blue Professional Information


Large intravenous doses of Methylene Blue (methylene blue injection) produce nausea, abdominal and precordial pain, dizziness, headache, profuse sweating, mental confusion and the formation of methemoglobin.

Use in Pregnancy

Safety for use in pregnancy has not been established. Use of Methylene Blue (methylene blue injection) in women of childbearing potential requires that anticipated benefits be weighed against possible hazards.

Read the entire FDA prescribing information for Methylene Blue (Methylene Blue Injection)

© Methylene Blue Patient Information is supplied by Cerner Multum, Inc. and Methylene Blue Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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