Note: This document contains side effect information about ethambutol. Some dosage forms listed on this page may not apply to the brand name Myambutol.

Applies to ethambutol: oral tablet.

Serious side effects of Myambutol

Along with its needed effects, ethambutol (the active ingredient contained in Myambutol) 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 immediately if any of the following side effects occur while taking ethambutol:

Less common

• Chills
• pain and swelling of joints, especially big toe, ankle, or knee
• tense, hot skin over affected joints

Rare

• Blurred vision, eye pain, red-green color blindness, or any loss of vision (more common with high doses)
• fever
• joint pain
• numbness, tingling, burning pain, or weakness in hands or feet
• skin rash

Other side effects of Myambutol

Some side effects of ethambutol 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:

Less common

• Abdominal pain
• confusion
• headache
• loss of appetite
• nausea and vomiting

For Healthcare Professionals

Applies to ethambutol: oral tablet.

General

The most commonly reported side effects included decreased visual acuity and optic neuritis.^[Ref]

Ocular

Common (1% to 10%): Decreased visual acuity, optic neuritis

Uncommon (0.1% to 1%): Color blindness, eye pain, loss of vision, scotoma, visual disturbances

Frequency not reported: Irreversible blindness, optic neuropathy, retrobulbar neuritis^[Ref]

Nervous system

Uncommon (0.1% to 1%): Visual field defect

Rare (0.01% to 0.1%): Extremity paresthesia (extremity numbness/tingling), numbness, peripheral neuritis, peripheral neuropathy

Very rare (less than 0.01%): Dizziness, headache^[Ref]

Metabolic

Uncommon (0.1% to 1%): Hyperuricemia

Very rare (less than 0.01%): Gout

Frequency not reported: Anorexia, precipitation of acute gout^[Ref]

Dermatologic

Rare (0.01% to 0.1%): Pruritus, rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria

Very rare (less than 0.01%): Bullous dermatitis, epidermal necrolysis, photosensitive lichenoid eruptions

Frequency not reported: Cutaneous reactions, dermatitis, erythema multiforme, exfoliative dermatitis^[Ref]

Hematologic

Rare (0.01% to 0.1%): Thrombocytopenia/reversible thrombocytopenia

Very rare (less than 0.01%): Leukopenia, neutropenia

Frequency not reported: Eosinophilia, lymphadenopathy^[Ref]

Hypersensitivity

Very rare (less than 0.01%): Anaphylactic reaction, anaphylactoid reactions, hypersensitivity, hypersensitivity syndrome^[Ref]

Psychiatric

Very rare (less than 0.01%): Disorientation, hallucinations, mental confusion^[Ref]

Respiratory

Very rare (less than 0.01%): Pneumonitis, pulmonary infiltrates with/without eosinophilia^[Ref]

Other

Very rare (less than 0.01%): Fever, malaise, pyrexia^[Ref]

Hepatic

Very rare (less than 0.01%): Hepatic failure

Frequency not reported: Abnormal liver function test values, hepatitis, jaundice, liver toxicity/fatal liver toxicity, transient impairment of liver function^[Ref]

Renal

Very rare (less than 0.01%): Interstitial nephritis^[Ref]

Musculoskeletal

Very rare (less than 0.01%): Joint pain^[Ref]

Gastrointestinal

Frequency not reported: Abdominal pain, diarrhea, gastrointestinal disorders, gastrointestinal upset, nausea, vomiting^[Ref]

Cardiovascular

Frequency not reported: Myocarditis, pericarditis^[Ref]