Methylthioninium chloride

By Medically reviewed by hellodoktor

Generic Name: Methylthioninium chloride Brand Name(s): Generics only. No brands available.


What is methylthioninium chloride used for?

Methylthioninium chloride is used to treat a condition called methemoglobinemia. This condition occurs when the blood cannot deliver oxygen where it is needed in the body.

It is also used for treating Herpes simplex, lithiasis, poisoning, urinary tract infections or preventing cyanosis.

How should I take methylthioninium chloride?

Methylthioninium chloride is injected only by or under the supervision of a doctor.

This medicine is given through a needle placed in one of your veins. It must be given very slowly, so the needle will remain in place for several minutes.

How do I store methylthioninium chloride?

Methylthioninium chloride is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store methylthioninium chloride in the bathroom or the freezer. There may be different brands of methylthioninium chloride that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush methylthioninium chloride down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using methylthioninium chloride?

Before using this drug, tell your doctor if:

  • You are allergic to any ingredient in methylthioninium chloride.
  • You are pregnant, planning to become pregnant, or are breastfeeding.
  • You are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement.
  • You have allergies to medicines, foods, or other substances.

Elderly patients are more likely to have kidney problems, which may require caution and an adjustment in the dose for patients receiving methylthioninium chloride.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using methylthioninium chloride during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking methylthioninium chloride. Methylthioninium chloride is pregnancy risk category X, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from methylthioninium chloride?

When using this drug, some common side effects may occur:

  • Change in taste
  • Changes in skin color
  • Feeling hot or cold
  • Increased sweating
  • Loss of taste
  • Muscle or joint pain
  • Pain at the infusion site
  • Pain in the arms or legs
  • Back pain
  • Bruising
  • Chills
  • General feeling of discomfort or illness
  • Large, flat, blue or purplish patches in the skin
  • Loss of appetite
  • Muscle aches and pains
  • Muscle spasm
  • Runny nose
  • Trouble sleeping

If any of the following side effects occur while taking methylthioninium chloride, check with your doctor or nurse immediately:

  • Agitation
  • Bluish-colored lips, fingernails, or palms
  • Confusion
  • Cough
  • Dark urine
  • Diarrhea
  • Difficulty breathing
  • Difficulty swallowing
  • Dizziness or lightheadedness
  • Fast heartbeat
  • Fever
  • Headache
  • Hives or welts, itching, or skin rash
  • Large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • Overactive reflexes
  • Pale skin
  • Poor coordination
  • Rapid heart rate
  • Redness of the skin
  • Restlessness
  • Shivering
  • Sore throat
  • Sweating
  • Talking or acting with excitement you cannot control
  • Tightness in the chest
  • Trembling or shaking
  • Twitching
  • Unusual bleeding or bruising
  • Unusual tiredness or weakness

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with methylthioninium chloride?

Methylthioninium chloride may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products may interact with your drug, including:

  • Amitriptyline
  • St John’s Wort
  • Sufentanil
  • Tapentadol
  • Tianeptine
  • Tramadol
  • Ziprasidone
  • Acarbose
  • Chlorpropamide
  • Insulin Detemir
  • Insulin Glargine, Recombinant
  • Insulin Glulisine
  • Insulin Lispro, Recombinant
  • Metformin
  • Nateglinide
  • Repaglinide
  • Morphine
  • Glipizide
  • Glyburide
  • Insulin
  • Insulin Aspart, Recombinant
  • Insulin Bovine
  • Insulin Deglude
  • Procarbazine
  • Rasagiline
  • Remifentanil
  • Sibutramine
  • Maprotiline
  • Milnacipran
  • Mirtazapine
  • Nortriptyline
  • Opicapone
  • Paroxetine
  • Phenelzine
  • Phentermine
  • Protriptyline
  • Pseudoephedrine
  • Rizatriptan
  • Safinamide
  • Selegiline
  • Sertraline
  • Sumatriptan
  • Tranylcypromine
  • Trazodone
  • Trimipramine
  • Tryptophan
  • Venlafaxine
  • Vilazodone
  • Vortioxetine
  • Zolmitriptan
  • Almotriptan
  • Amineptine
  • Amitriptylinoxide
  • Bromazepam
  • Brompheniramine
  • Buprenorphine
  • Buspirone
  • Butorphanol
  • Chlorpheniramine
  • Cocaine
  • Codeine
  • Dextromethorphan
  • Dibenzepin
  • Difenoxin
  • Dihydrocodeine
  • Diphenoxylate
  • Dolasetron
  • Eletriptan
  • Fentanyl
  • Flibanserin
  • Frovatriptan
  • Furazolidone
  • Granisetron
  • Hydrocodone
  • Iobenguane I 123
  • Iproniazid
  • Lithium
  • Lofepramine
  • Lorcaserin
  • Melitracen
  • Meperidine
  • Methadone
  • Moclobemide

Does food or alcohol interact with methylthioninium chloride?

Methylthioninium chloride may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with methylthioninium chloride?

Methylthioninium chloride may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Especially if you have:

  • Glucose-6-phosphate dehydrogenase (G6PD) deficiency (a hereditary metabolic disorder affecting red blood cells)
  • Kidney disease
  • Liver disease


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using methylthioninium chloride.

What is the dose of methylthioninium chloride for an adult?


Drug-induced methemoglobinemia: the recommended dose is 1 to 2 mg/kg intravenously. May repeat in one hour if necessary.

Inject intravenously very slowly over a period of several minutes to prevent local high concentration of the compound from producing additional methemoglobin.


Ifosfamide-induced encephalopathy (unlabeled use): (Treatment may not be necessary; encephalopathy may improve spontaneously)

Prevention: the recommended dose is 50 mg every 6 to 8 hours.

Treatment: the recommended dose is 50 mg as a single dose or every 4 to 8 hours until symptoms resolve.

What is the dose of methylthioninium chloride for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is methylthioninium chloride available?

Methylthioninium chloride is available in the following dosage forms and strengths:

  • Solution 10ml
  • Tablet 55mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

Symptoms of overdose:

  • Abdominal or stomach pain
  • Bigger, dilated, or enlarged pupils (black part of the eye)
  • Blue staining of the urine, skin, and mucous membranes
  • Bluish-colored lips, fingernails, or palms
  • Blurred vision
  • Burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feelings
  • Confusion
  • Dark urine
  • Difficulty breathing
  • Dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • Fear
  • Fever
  • Headache
  • Increased sensitivity of the eyes to light
  • Nausea
  • Pale skin
  • Rapid heart rate
  • Rapid shallow breathing
  • Shakiness in the legs, arms, hands, or feet
  • Sore throat
  • Tightness in the chest
  • Unusual bleeding or bruising
  • Unusual tiredness or weakness
  • Vomiting

What should I do if I miss a dose?

If you miss a dose of methylthioninium chloride, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

msBahasa Malaysia

Review Date: April 10, 2017 | Last Modified: September 13, 2019

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