Ethambutol: uses, dosing, side effects & brands
Ethambutol is a medicine sold in the U.S. under one brand, for nontuberculous mycobacterium infections and tuberculosis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Treats
- Nontuberculous Mycobacterium Infections and Tuberculosis
- Available as
- Tablet
- Sold as
- Ethambutol Hydrochloride
- Prescription?
- Prescription only
- Generic available?
- Yes
- What the pharmacy pays
- about $13 for a 30-count supply — not your price
How ethambutol is dosed
From the FDA label for Ethambutol Hydrochloride (application ANDA078939). Other ethambutol products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Ethambutol hydrochloride should not be used alone, in initial treatment or in retreatment. Ethambutol hydrochloride should be administered on a once every 24-hour basis only. Absorption is not significantly altered by administration with food. Therapy, in general, should be continued until bacteriological conversion has become permanent and maximal clinical improvement has occurred. Ethambutol hydrochloride is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established. Initial Treatment In patients who have not received previous antituberculous therapy, administer ethambutol hydrochloride 15 mg/ kg (7 mg/lb) of body weight, as a single oral dose once every 24 hours. In the more recent studies, isoniazid has been administered concurrently in a single, daily, oral dose. Retreatment In patients who have received previous antituberculous therapy, administer ethambutol hydrochloride 25 mg/kg (11 mg/lb) of body weight, as a single oral dose once every 24 hours. Concurrently administer at least one other antituberculous drug to which the organisms have been demonstrated to be susceptible by appropriate in-vitro tests. Suitable drugs usually consist of those not previously used in the treatment of the patient. After 60 days of ethambutol hydrochloride administration, decrease the dose to 15 mg/kg (7 mg/lb) of body…
Ethambutol side effects
Ethambutol hydrochloride may produce decreases in visual acuity, including irreversible blindness, which appear to be due to optic neuritis. Optic neuropathy including optic neuritis or retrobulbar neuritis occurring in association with ethambutol therapy may be characterized by one or more of the following events: decreased visual acuity, scotoma, color blindness, and/or visual defect. These events have also been reported in the absence of a diagnosis of optic or retrobulbar neuritis. Patients should be advised to report promptly to their physician any change of visual acuity. The change in visual acuity may be unilateral or bilateral and hence each eye must be tested separately and both eyes tested together. Testing of visual acuity should be performed before beginning ethambutol hydrochloride therapy and periodically during drug administration, except that it should be done monthly when a patient is on a dosage of more than 15 mg per kilogram per day. Snellen eye charts are recommended for testing of visual acuity. Studies have shown that there are definite fluctuations of one or two lines of the Snellen chart in the visual acuity of many tuberculous patients not receiving ethambutol. The following table may be useful in interpreting possible changes in visual acuity attributable to ethambutol. Initial Snellen Reading Reading Indicating Significant Decrease Significant…
Who shouldn’t take ethambutol
Ethambutol hydrochloride is contraindicated in patients who are known to be hypersensitive to this drug. It is also contraindicated in patients with known optic neuritis unless clinical judgement determines that it may be used. Ethambutol hydrochloride is contraindicated in patients who are unable to appreciate and report visual side effects or changes in vision (e.g., young children, unconscious patients).
Ethambutol drug interactions
The results of a study of coadministration of ethambutol hydrochloride (50mg/kg) with an aluminum hydroxide containing antacid to 13 patients with tuberculosis showed a reduction of mean serum concentrations and urinary excretion of ethambutol of approximately 20% and 13%, respectively, suggesting that the oral absorption of ethambutol may be reduced by these antacid products. It is recommended to avoid concurrent administration of ethambutol with aluminum hydroxide containing antacids for at least 4 hours following ethambutol administration.
Every ethambutol product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Ethambutol Hydrochloride.
What ethambutol pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
How long ethambutol keeps
No ethambutol label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Ethambutol and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for ethambutol: levels in milk, effects in breastfed infants, and the drugs it would consider insteadLimited information indicates that maternal doses of ethambutol up to 15 mg/kg daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. The amount of ethambutol in milk is insufficient to treat tuberculosis in the breastfed infant. The Centers for Disease Control and Prevention and other professional organizations state that breastfeeding should not be discouraged in women taking ethambutol.
National Institute of Child Health and Human Development, record revised August 15, 2024. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about ethambutol
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 2,744 reports naming ethambutol, and the FDA flagged 82% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- pyrexia167 reports
- nausea132 reports
- vomiting123 reports
- drug intolerance106 reports
- dyspnoea96 reports
- cough94 reports
- diarrhoea89 reports
- immune reconstitution syndrome87 reports
Read these as a signal, not a rate. A report does not mean ethambutol caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label.
Source: openFDA drug/event (FAERS), retrieved September 25, 2026.
Related calculators
Frequently asked questions
What is ethambutol?
Ethambutol hydrochloride is an oral chemotherapeutic agent which is specifically effective against actively growing microorganisms of the genus Mycobacterium , including M. tuberculosis. Ethambutol hydrochloride is a white, crystalline powder, It is freely soluble in water; soluble in alcohol and in methanol.
Can you take ethambutol with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run ethambutol against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does ethambutol come in?
Across the brands we track, ethambutol is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic ethambutol?
Yes. Our catalog lists 1 generic ethambutol product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Ethambutol: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/ethambutol
- MLA
- “Ethambutol: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/ethambutol.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for ethambutol on DailyMed (NIH) ↗.