What is Methylene Blue?
Methemoglobin is a form of hemoglobin (HEEM o glo bin). Hemoglobin is a substance in blood that carries oxygen and distributes it to your tissues and organs. However, methemoglobin is not a type of hemoglobin that is useful in carrying oxygen.
Methemoglobin normally exists in small amounts in the blood. However, when methemoglobin levels increase, the blood is less efficient in circulating oxygen. The resulting lack of oxygen throughout the body can cause symptoms such as pale or blue-colored skin.
Methemoglobinemia is a condition in which methemoglobin is present in high levels in the blood. Methemoglobinemia usually occurs when a person is exposed to certain drugs or chemicals such as nitrites. It may also be caused by a genetic disorder.
Methylene blue injection is used to treat methemoglobinemia. It works by converting methemoglobin to a more efficient type of hemoglobin to better carry oxygen throughout the body.
Methylene blue oral is used to treat methemoglobinemia and urinary tract infections. It works as a mild antiseptic to kill bacteria in the urinary tract. You will most likely also be given an antibiotic medication to treat your infection.
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 may also be used for other purposes not listed in this medication guide.
What is the most important information I should know about Methylene Blue?
You should not use this medication if you are allergic to methylene blue, or if you have severe kidney problems.
Before using methylene blue, tell your doctor if you have kidney disease, or glucose-6-phosphate dehydrogenase (G6PD) deficiency.
Also tell your doctor about all other medications you use, especially antacids, diuretics (water pills), sodium bicarbonate, or acetazolamide (Diamox).
Methylene blue will most likely cause your urine or stools to appear blue or green in color. This is a normal side effect of the medication and will not cause any harm.
This medication can cause you to have unusual results with certain medical tests. Tell any doctor who treats you that you are using methylene blue.
Call your doctor at once if you have a serious side effect such as severe vomiting or stomach pain, pain in your chest or behind your breast bone, pale or blue skin, high fever, fast or pounding heartbeats, trouble breathing, confusion, or feeling like you might pass out.
What should I discuss with my healthcare provider before taking Methylene Blue?
You should not use this medication if you are allergic to methylene blue, or if you have severe kidney problems.
If you have certain conditions, you may need a dose adjustment or special tests to safely use this medication. Before using methylene blue, tell your doctor if you have:
- kidney disease; or
- glucose-6-phosphate dehydrogenase (G6PD) deficiency
FDA pregnancy category C. Methylene blue may cause harm to an unborn baby, but the medication may sometimes be used during pregnancy. Your doctor will determine whether or not this medication is safe or if it will harm the unborn baby. Before you are treated with methylene blue, 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. Do not use this medication without telling your doctor if you are breast-feeding a baby.
Methylene Blue Side Effects
What are the possible side effects of Methylene Blue?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have a serious side effect such as:
- severe nausea, vomiting, or stomach pain
- pain in your chest or behind your breast bone
- pale or blue skin
- high fever, fast or pounding heartbeats, trouble breathing; or
- confusion, feeling like you might pass out
Less serious side effects may include:
- mild bladder irritation
- mild nausea, vomiting, diarrhea, upset stomach
- dizziness
- headache; or
- increased sweating
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.
Methylene Blue Interactions
What other drugs affect Methylene Blue?
Tell your doctor about all other medications you use, especially:
- acetazolamide (Diamox)
- antacids
- sodium bicarbonate; or
- a diuretic (water pill) such as hydrochlorothiazide, HCTZ, Accuretic, Aldactazide, Aldoril, Atacand HCT, Avalide, Capozide, Diovan HCT, Dyazide, HydroDiuril, Hyzaar, Inderide, Lopressor HCT, Lotensin HCT, Maxzide, Moduretic, Vaseretic, Zestoretic, Ziac, and others
This list is not complete and there may be other drugs that can interact with methylene blue. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.
What should I avoid while taking Methylene Blue?
Follow your doctor’s instructions about any restrictions on food, beverages, or activity while you are using methylene blue.
Methylene Blue Dosage
How should I take Methylene Blue?
Use this medication exactly as prescribed by your doctor. Do not use it in larger amounts or for longer than recommended. Follow the directions on your prescription label.
The usual dose of oral methylene blue is 1 or 2 tablets after meals, 3 times per day.
Take the methylene blue tablet with a full glass (8 ounces) of water.
Methylene blue injection is given through a needle placed into a vein. Your doctor, nurse, or other healthcare provider will give you this injection in a clinic or hospital setting.
To be sure this medication is helping your condition, your blood may need to be tested often. This will help your doctor determine how long to treat you with methylene blue. Do not miss any scheduled appointments.
Methylene blue will most likely cause your urine or stools to appear blue or green in color. This is a normal side effect of the medication and will not cause any harm.
This medication can cause you to have unusual results with certain medical tests. Tell any doctor who treats you that you are using methylene blue.
Store methylene blue tablets at room temperature away from moisture, heat, and light.
What happens if I overdose on Methylene Blue?
Seek emergency medical attention if you think you have used too much of this medicine.
Overdose symptoms may include anxiety, confusion, sweating, nausea, vomiting, stomach pain, chest pain, pale or yellowed skin, dark colored urine, fever, or weakness.
What happens if I miss a dose of Methylene Blue?
Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.
Edited from everydayhealth.com