Applies to methylene blue: intravenous solution.

Serious side effects of Methylene blue

Along with its needed effects, methylene blue may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking methylene blue:

Incidence not known

• 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

Get emergency help immediately if any of the following symptoms of overdose occur while taking methylene blue:

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 or lightheadedness
• 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

Other side effects of Methylene blue

Some side effects of methylene blue may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• 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

Less common

• 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

For Healthcare Professionals

Applies to methylene blue: compounding powder, injectable solution, intravenous solution, oral tablet.

Cardiovascular

Common (1% to 10%): Chest pain, chest discomfort, presyncope, syncope

Frequency not reported: Cardiac arrhythmia, tachycardia, hypertension, hypotension, palpitations^[Ref]

Hematologic

Common (1% to 10%): Ecchymosis

Frequency not reported: Hemolytic anemia, hemolysis, methemoglobinemia, hemoglobin decreased, hyperbilirubinemia (in infants only)^[Ref]

Hypersensitivity

Frequency not reported: Anaphylaxis^[Ref]

Immunologic

Common (1% to 10%): Influenza-like illness^[Ref]

Local

Common (1% to 10%): Injection site pain, injection site discomfort

Frequency not reported: Infusion site extravasation, infusion site induration, infusion site pruritus, infusion site swelling, infusion site urticaria, peripheral swelling^[Ref]

Musculoskeletal

Very common (10% or more): Pain in extremity (84%)

Common (1% to 10%): Musculoskeletal pain, back pain, muscle spasms, chills, arthralgia

Frequency not reported: Serotonin syndrome, myalgia^[Ref]

Ocular

Frequency not reported: Mydriasis, eye pruritus, ocular hyperemia, vision blurred^[Ref]

Metabolic

Common (1% to 10%): Decreased appetite, limb discomfort

Frequency not reported: Local tissue necrosis at the injection site^[Ref]

Psychiatric

Common (1% to 10%): Anxiety

Frequency not reported: Confusional state, agitation^[Ref]

Genitourinary

Very common (10% or more): Chromaturia (blue-green) (74%)

Frequency not reported: Dysuria^[Ref]

Hepatic

Frequency not reported: Elevated liver enzymes^[Ref]

Respiratory

Common (1% to 10%): Dyspnea

Frequency not reported: Dyspnea, tachypnea, hypoxia, nasal congestion, rhinorrhea, sneezing^[Ref]

Other

Very common (10% or more): Feeling hot (17%), fever

Common (1% to 10%): Feeling cold, discomfort, catheter site pain

Frequency not reported: Genotoxicity, fever, lack of effectiveness, interference with in-vivo monitoring devices, interference with laboratory tests^[Ref]

Nervous system

Very common (10% or more): Dysgeusia (20%), dizziness (16%), headache (10%), paresthesia

Common (1% to 10%): Headache, paresthesia oral, dizziness postural

Frequency not reported: Serotonin syndrome (with concomitant use of serotonergic drugs), tremor, aphasia, tremor, aphasia^[Ref]

Dermatologic

Very common (10% or more): Skin discoloration (blue) (13%), hyperhidrosis (13%), sweating

Common (1% to 10%): Pallor, contact dermatitis, pruritus, cold sweat, erythema

Frequency not reported: Urticaria, necrotic ulcer, papule, phototoxicity, rash (blue macules, severe burning pain)^[Ref]

Gastrointestinal

Very common (10% or more): Nausea (13%)

Common (1% to 10%): Vomiting, abdominal pain, diarrhea, hypoesthesia oral, oral discomfort

Frequency not reported: Feces discoloration (blue-green), dry mouth, flatulence, glossodynia, tongue eruption, thirst, oropharyngeal pain, blue colored saliva^[Ref]