Health Guide

Methylene blue (Into a vein)

Methylene Blue (METH-i-leen BLOO)

Treats methemoglobinemia.

Brand Name(s):


There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. You should not receive it if you had an allergic reaction to methylene blue or any thiazine dye, or if you are pregnant.

How to Use This Medicine:


  • Your doctor will prescribe your dose and schedule. This medicine is given through a needle placed in a vein.
  • A nurse or other health provider will give you this medicine.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Some medicines can affect how methylene blue works. Tell your doctor if you are using any of the following:
    • Alfentanil, cyclosporine, digoxin, dihydroergotamine, ergotamine, fentanyl, linezolid, phenytoin, pimozide, quinidine, sirolimus, tacrolimus, or warfarin
    • MAO inhibitors
    • Medicine to treat depression (including SSRIs, bupropion, buspirone, clomipramine, mirtazapine, venlafaxine)
    • Medicine to treat migraine headaches

Warnings While Using This Medicine:

  • It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant.
  • Tell your doctor if you have kidney disease, liver disease, or a glucose-6-phosphate dehydrogenase (G6PD) deficiency.
  • Do not breastfeed during treatment and for up to 8 days afterward.
  • This medicine may cause the following problems:
    • Serious drug reaction called serotonin syndrome (usually when taken with medicine to treat depression)
    • Hemolytic anemia
  • This medicine may cause dizziness, confusion, or vision problems. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.
  • This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.
  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Anxiety, restlessness, fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, seeing or hearing things that are not there
  • Trouble breathing, tiredness, uneven heartbeat, yellow skin or eyes
  • Unusual bleeding or bruising

If you notice these less serious side effects, talk with your doctor:

  • Blue discoloration of the skin
  • Change in sense of taste
  • Headache, dizziness, vision changes
  • Pain, itching, burning, swelling, or a lump under your skin where the needle is placed

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 6/18/2019
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

All rights reserved