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Related to Myambutol: Pyrazinamide, ethambutol

ethambutol hydrochloride

Etibi (CA), Myambutol

Pharmacologic class: Synthetic antitubercular

Therapeutic class: Antitubercular, antileprotic

Pregnancy risk category B


Unknown. Thought to interfere with RNA synthesis of bacterial metabolites, decreasing mycobacterial replication.


Tablets: 100 mg, 400 mg

Indications and dosages

Adjunct in tuberculosis and atypical mycobacterial infection caused by Mycobacterium tuberculosis

Adults and adolescents: In patients who haven't received previous antitubercular therapy, 15 mg/kg P.O. daily. In patients who have received previous antitubercular therapy, 25 mg/kg P.O. daily, decreased after 60 days to 15 mg/kg daily.

Dosage adjustment

• Renal impairment


• Hypersensitivity to drug


Use cautiously in:
• impaired renal or hepatic function, cataracts, optic neuritis, recurrent eye inflammation, diabetic retinopathy, gout
• pregnant patients
• children younger than age 13.


• Obtain specimens for culture and sensitivity testing, as necessary, before starting therapy and periodically throughout therapy.
• Give with food.

Adverse reactions

CNS: confusion, disorientation, malaise, dizziness, hallucinations, headache, peripheral neuritis

EENT: optic neuritis, blurred vision, decreased visual acuity, red-green color blindness, eye pain

GI: nausea, vomiting, abdominal pain, GI upset, anorexia

Hematologic: eosinophilia, thrombocytopenia

Hepatic: transient hepatic impairment

Metabolic: hyperuricemia, hypoglycemia

Musculoskeletal: joint pain, gouty arthritis

Respiratory: bloody sputum, pulmonary infiltrates

Skin: rash, pruritus, toxic epidermal necrolysis

Other: fever, anaphylactoid reactions


Drug-drug.Aluminum salts: delayed and reduced ethambutol absorption Other neurotoxic drugs: increased risk of neurotoxicity

Drug-diagnostic tests.Alanine aminotransferase, aspartate aminotransferase, bilirubin, uric acid: increased levels Glucose: decreased level

Patient monitoring

Watch for serious adverse reactions, such as thrombocytopenia, respiratory problems, and anaphylactoid reactions.
• Monitor liver function tests, CBC, and blood urea nitrogen, creatinine glucose, and serum uric acid levels.
• Give analgesics for drug-induced pain, as prescribed.
• Observe for signs and symptoms of gout.

Patient teaching

• Instruct patient to take with 8 oz of water. If stomach upset occurs, advise him to take with food.
• If patient must take antacids, advise him to take only aluminum-free antacids.

Tell patient to immediately report easy bruising or bleeding, respiratory problems, or signs and symptoms of hypersensitivity reactions.
• Advise patient to report vision changes and to have annual eye exams. Reassure him that visual disturbances will subside within several weeks to months after drug is discontinued.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.


(mī-ăm′byə-tôl′, - tōl′)
A trademark for the drug ethambutol hydrochloride.


a trademark for an antitubercular (ethambutol hydrochloride).


See ETHAMBUTOL. Myambutol was formerly a brand name for ethambutol but is now a generic name.