Ethambutol
Ethambutol is an antibiotic used together with other tuberculosis medicines to treat pulmonary tuberculosis (tuberculosis of the lungs).
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 8 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Ethambutol is one of the standard first-choice drugs for tuberculosis of the lungs, always paired with other TB medicines to stop the bacteria multiplying; it has been on the market since about 1967 and is available as a generic. Most people tolerate it well, with upset stomach, nausea or poor appetite the usual complaints. The thing to watch is your eyesight, since it can inflame the eye nerve (optic neuritis), so report blurring, trouble seeing colors or blind spots at once; this usually reverses if caught early, but permanent blindness has been reported. Keep every eye exam and liver blood test, since liver damage, including deaths, has also occurred.
Clinical pearls
- Take it once daily; food barely affects absorption, so taking it with a meal to settle your stomach is fine.
- If you use an aluminum hydroxide antacid, wait at least 4 hours after your ethambutol dose before taking it.
- Tell your prescriber about any kidney problems, because ethambutol can build up in the body when kidney function is reduced.
- Sudden joint pain is worth reporting, since gout attacks have been reported with ethambutol.
Patient information guide A plain-language walkthrough of Ethambutol, written from its FDA label.
What Ethambutol is used for
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Ethambutol treats one main condition.
- Pulmonary tuberculosis (lung TB), always combined with at least one other anti-TB drug.
- Ethambutol Hydrochloride tablets (including the film-coated tablet) are labeled for this use, both for first-time treatment and for retreatment.
How Ethambutol works
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Ethambutol moves into actively growing tuberculosis bacteria. It appears to block the making of substances they need. This disrupts their metabolism, stops them from multiplying and leads to cell death.
Bacteria can become resistant if ethambutol is used alone, which is why it is paired with other TB drugs. It has also reduced the emergence of resistance to isoniazid when the two are used together.
Ethambutol dosage
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Ethambutol Hydrochloride tablets are taken by mouth once every 24 hours. Food does not significantly change absorption.
- It should never be used alone.
- Your dose depends on your body weight and whether you have had TB treatment before.
- In retreatment, a higher dose is used at first and is then lowered after 60 days. Monthly eye exams are advised during the higher dose.
- Treatment generally continues until the infection is permanently controlled and you have improved as much as possible.
Follow your prescriber and the label.
Dosing details from the FDA-approved label
From the Ethambutol prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Initial Treatment (patients who have not received previous antituberculous therapy)
- 15 mg/kg (7 mg/lb) of body weight, as a single oral dose once every 24 hours
- In more recent studies, isoniazid has been administered concurrently in a single, daily, oral dose. Not for use alone. Absorption is not significantly altered by food. Not recommended in pediatric patients under thirteen years of age.
- Retreatment (patients who have received previous antituberculous therapy)
- 25 mg/kg (11 mg/lb) of body weight, as a single oral dose once every 24 hours
- After 60 days, decrease the dose to 15 mg/kg (7 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 are susceptible; monthly eye examinations are advised while on 25 mg/kg daily dose.
Read the label’s full dosing text
DOSAGE AND ADMINISTRATION 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 weight, and administer as a single oral dose once every 24 hours. During the period when a patient is on a daily dose of 25 mg/kg, monthly eye examinations are advised. See Table for easy selection of proper weight-dose tablet(s). Weight-Dose Table 15 mg/kg (7 mg/lb) Schedule Weight Range Daily Dose Pounds Kilograms --------------------------------- In mg Under 85 lbs.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Ethambutol side effects
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Many people have mild stomach or general symptoms.
Common side effects
- Loss of appetite
- Nausea and vomiting
- Stomach upset or abdominal pain
- Headache
- Dizziness
- Fever or feeling unwell
- Joint pain
- Itching or skin rash
When to get medical help
- Call your doctor right away if you notice any change in your vision, such as blurred vision, trouble seeing colors or blind spots. Ethambutol can cause optic neuritis (swelling and damage of the eye nerve).
- Get help for signs of liver problems. Liver toxicity, including deaths, has been reported.
- Seek urgent help for a serious allergic reaction or a widespread rash with fever, swollen glands or organ symptoms.
- Report numbness or tingling in your hands or feet.
- Report confusion, disorientation or hallucinations.
- Tell your doctor about sudden joint pain, since gout attacks have been reported.
- Report new breathing problems, since lung changes (pulmonary infiltrates) have been reported.
Ethambutol warnings and precautions
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- Eye damage: Ethambutol can lower vision through optic neuritis. It is usually reversible if stopped promptly, but permanent blindness has been reported.
- Vision monitoring: Each eye should be tested before treatment and periodically after, monthly at higher doses. Report blurred vision or other eye symptoms right away.
- Liver toxicity: Serious cases, including deaths, have been reported. Liver tests are advised at baseline and periodically.
- Uric acid and gout: Ethambutol can raise uric acid levels and trigger acute gout.
- Blood counts: Low platelets and white blood cells have been reported.
Ethambutol interactions
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One interaction is highlighted on the label.
- Aluminum hydroxide antacids: they can reduce ethambutol absorption. Avoid them for at least 4 hours after taking ethambutol.
- Other TB drugs: ethambutol is always combined with them, and some side effects may come from the combination.
Interactions listed in the FDA-approved label
From the Ethambutol prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Aluminum hydroxide containing antacids: In 13 patients with tuberculosis given ethambutol 50 mg/kg, mean serum concentrations and urinary excretion of ethambutol were reduced by approximately 20% and 13%, respectively, suggesting oral absorption of ethambutol may be reduced. Avoid concurrent administration of ethambutol with aluminum hydroxide containing antacids for at least 4 hours following ethambutol administration.
Read the label’s full interactions text
Drug Interactions The results of a study of coadministration of ethambutol hydrochloride (50 mg/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.
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Ethambutol
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- Do not use it if you are allergic to ethambutol.
- Tell your doctor if you have optic neuritis. It is generally not used unless your doctor judges it appropriate.
- It is not for people who cannot notice and report vision changes, such as young children or unconscious patients.
- It is not recommended for children under 13.
- Kidney problems can cause ethambutol to build up in the body.
- Tell your doctor about any liver problems.
What Ethambutol does in the body
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Ethambutol stops the growth of tuberculosis bacteria by disrupting their metabolism, and it kills them. It is effective against Mycobacterium tuberculosis but does not seem to work against fungi, viruses or other bacteria. No cross-resistance with other TB drugs has been shown.
How your body processes Ethambutol
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After a dose by mouth, blood levels peak in about 2 to 4 hours. Levels fall to undetectable within 24 hours, except in some people with abnormal kidney function. About half of a dose leaves unchanged in the urine, and a smaller portion leaves as metabolites. About 20 to 22 percent is passed unchanged in the stool. It does not build up in people with normal kidney function but can build up markedly with kidney insufficiency.
How to store Ethambutol
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Store at controlled room temperature 20° to 25° C (68° to 77° F).
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Ethambutol
17 supplements and herbal products have documented interactions with Ethambutol in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 7
- Minor · 9
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nutrient depletion considerations
Ethambutol has been associated with lower levels of 2 nutrients in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.
Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.
Ethambutol: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Ethambutol — the kind of thing our pharmacy team would talk through with you at the counter.
What is ethambutol for?
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How should I take it?
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What side effects should I watch for?
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Will I need eye tests?
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Can I take antacids with it?
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Can my child take ethambutol?
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Is Ethambutol available over the counter?
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When was Ethambutol first available?
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Who makes Ethambutol?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Ethambutol on HelloPharmacist
Ethambutol forms and strengths (how it comes)
Ethambutol is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Ethambutol Hydrochloride tablets are used to treat pulmonary tuberculosis, together with at least one other anti-TB drug.
- Ethambutol Hydrochloride tablets are taken by mouth once every 24 hours.
- Ethambutol Hydrochloride tablets can be taken with or without food, since food does not significantly change absorption.
- Ethambutol Hydrochloride tablets are not recommended for children under 13 years old.
Ethambutol on the U.S. market: products, makers and brands
How Ethambutol appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
7 companies list 13 Ethambutol product records with the FDA, mostly as tablet; the earliest marketing or approval year on record is 1967. Brand names on the directory include Myambutol; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (1) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
How widely Ethambutol is used (Medicaid data)
A general measure of how commonly Ethambutol is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Ethambutol is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Ethambutol prescribed? Of the 1,601 medications we measure, Ethambutol ranks #941 by Medicaid prescriptions — more than 41% of them.
Utilization by Ethambutol product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
ethambutol hydrochloride 400 MG Oral Tablet Most dispensed
Summed across the 3 of 19 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 995607
ethambutol hydrochloride 100 MG Oral Tablet
Summed across the 1 of 13 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 995599
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Ethambutol, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 4 of 32 listed Ethambutol NDCs with Medicaid activity.
Compare Ethambutol products
A representative set of FDA-listed product records for Ethambutol — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 400 mg | Oral | American Health Packaging | ANDA | View NDC → |
| 100 mg | Oral | Epic Pharma, LLC | ANDA | View NDC → |
| 400 mg | Oral | Epic Pharma, LLC | ANDA | View NDC → |
| 100 mg | Oral | Kanchan Healthcare Inc | NDA AUTHORIZED GENERIC | View NDC → |
| 400 mg | Oral | Kanchan Healthcare Inc | NDA | View NDC → |
| 100 mg | Oral | Lupin Pharmaceuticals, Inc. | ANDA | View NDC → |
| 400 mg | Oral | Lupin Pharmaceuticals, Inc. | ANDA | View NDC → |
| 100 mg | Oral | Marlex Pharmaceuticals, Inc. | NDA | View NDC → |
| 400 mg | Oral | Marlex Pharmaceuticals, Inc. | NDA | View NDC → |
| 100 mg | Oral | Remedyrepack Inc. | ANDA | View NDC → |
| 400 mg | Oral | Remedyrepack Inc. | ANDA | View NDC → |
| 100 mg | Oral | STI Pharma LLC | NDA AUTHORIZED GENERIC | View NDC → |
| 400 mg | Oral | STI Pharma LLC | NDA AUTHORIZED GENERIC | View NDC → |
Showing 13 of 13 products — FDA National Drug Code Directory. See every product, package size and price: browse all 13 Ethambutol NDCs →
Ethambutol side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Ethambutol — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Ethambutol in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Ethambutol FDA approval history
How Ethambutol went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Ethambutol recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Ethambutol recalls since July 2021.
✅No Ethambutol recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 4110 1 dose form · 2 strengths
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Dose form (SCDF) Oral Tablet RxCUI 372091In current FDA listings
Look up RxCUI 4110 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Ethambutol supply and shortage status
Whether Ethambutol is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
💵 What Ethambutol costs pharmacies (NADAC benchmark)
The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Sep 30, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.
| Form | Strength | Pharmacy acquisition benchmark | |
|---|---|---|---|
| Tablet · Oral | 400 mg | $0.458 per tablet | NDC details & price history |
| Tablet · Oral | 100 mg | $0.304 per tablet | NDC details & price history |
Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.
Ethambutol brand names
Ethambutol is sold under one brand name in the FDA directory — Myambutol. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Ethambutol: manufacturers and labelers
7 companies list Ethambutol products with the FDA. By number of product records, the largest are Epic Pharma, LLC, Kanchan Healthcare Inc, Lupin Pharmaceuticals, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Ethambutol drug class (RxNorm)
Ethambutol belongs to the Antimycobacterial class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Ethambutol page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. STI Pharma LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →