Generic name
Ethambutol hydrochloride: adverse event reports filed with FDA
1,705 reports list it as a suspect or interacting product, 2004–2026. Class: Antimycobacterial. Also reported as Ethambutol Hcl, Ethambutol Hydrochloride Tablet 400mg, Ethambutol Hydrochloride Tablets Usp 400mg.
- 1,705
- reports as suspect product
- 0% of all reports · about 76 a year
- 220
- reports, 12 months to June 2026
- 227 in the 12 months before
- 75.1%
- marked serious by the reporter
- 92.6% across the class
- 10.5%
- record death among outcomes, as reported
- 179 reports · not verified by FDA
Between January 2004 and June 2026, 1,705 adverse event reports received by FDA list ethambutol hydrochloride, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (1,403) are left out of every figure here.
In the 12 months to June 2026, 220 reports listed it, close to the 227 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 76 reports a year and 0% of the 20,646,523 reports in the database, and 7.6% of the reports for the antimycobacterial class. How many people take it is not in the data, so a count is not a rate of occurrence.
Reporters most often recorded product use in unapproved indication (11.8%), drug intolerance (5.7%) and pyrexia (4.9%). A report can list several reactions, so shares add to more than 100%; 434 different terms appear across these reports. Product use in unapproved indication is recorded in 11.8% of these reports, a larger share than in the median antimycobacterial drug (1.9%).
75.1% of the reports are marked serious by the reporter (92.6% across the class); 10.5% record death among the outcomes and 34.9% record hospitalisation, as reported. 37.3% of the reports came from physicians, and the largest patient age group is 45 to 64 (24%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Ethambutol hydrochloride reports recording the termmedian drug in antimycobacterial
- Product use in unapproved indicationused for a purpose not on the label11.8%201
- Drug intolerancethe medicine was not tolerated5.7%98
- Pyrexiafever4.9%83
- Nauseafeeling sick4.1%70
- Drug interactionan interaction between medicines3.5%60
- Vomitingbeing sick3.3%57
- Paradoxical drug reaction3.2%54
- Off label useused for a purpose or in a way not on the label2.9%49
- Condition aggravatedthe condition being treated got worse2.5%42
- Rashskin rash2.3%40
- Hepatotoxicityliver injury2.3%39
- Neutropenialow neutrophils, a type of white blood cell2.2%38
- Hepatic cytolysis2.2%37
- Visual impairmentreduced vision2.2%37
- Dyspnoeashortness of breath2%34
- Coughcough1.9%33
- Optic neuritis1.9%33
- Blindnessloss of sight1.9%32
- Decreased appetitereduced appetite1.8%31
- Drug resistance1.8%31
- Fatiguetiredness1.8%31
- Mycobacterium avium complex infection1.8%31
- Rash maculo-papulara rash of flat and raised spots1.8%31
- Drug ineffectivethe medicine did not work as expected1.8%30
- Vision blurredblurred vision1.8%30
- Diarrhoealoose or frequent stools1.5%26
- Optic neuropathy1.5%26
- Neuropathy peripheralnerve damage in hands or feet1.5%25
Top 30 of 434 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 6 drugs in the antimycobacterial class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 22,556 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 35.7% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Tuberculosis | 322 | 18.9% |
| Mycobacterium avium complex infection | 314 | 18.4% |
| Pulmonary tuberculosis | 202 | 11.8% |
| Atypical mycobacterial infection | 66 | 3.9% |
| Mycobacterial infection | 46 | 2.7% |
| Disseminated tuberculosis | 44 | 2.6% |
The indication field is filled in by the reporter and is often blank; shares are of all 1,705 reports.
In context
| Measure | Ethambutol hydrochloride | Antimycobacterial | All reports |
|---|---|---|---|
| Reports as suspect product | 1,705 | 22,556 | 20,646,523 |
| Share of that pool | — | 7.6% | 0% |
| Reports, latest 12 months | 220 | — | 1,332,454 |
| Marked serious | 75.1% | 92.6% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 105 | 179 | 91 |
| Hospitalisation recorded, per 1,000 reports | 349 | 391 | 213 |
| Consumer-filed share | 15.7% | 7.2% | 45.8% |
| Top term, share of reports | Product use in unapproved indication 11.8% | median 1.9% | 1.2% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Other drugs in the antimycobacterial class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Isoniazid | generic | 9,024 | 462 | 93.6% |
| Pyrazinamide | generic | 6,334 | 404 | 97.7% |
| Clofazimine | generic | 4,076 | 330 | 90.8% |
| Lamprene | brand | 775 | 90 | 84.4% |
| Pretomanid | generic | 642 | 179 | 98.1% |
Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.
Questions about Ethambutol hydrochloride reports
How many adverse event reports has FDA received for Ethambutol hydrochloride?
1,705 reports list Ethambutol hydrochloride as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 220 of them arrived in the latest 12 months. Another 1,403 list it only as a concomitant medication.
What reactions are recorded in Ethambutol hydrochloride reports?
product use in unapproved indication (11.8%), drug intolerance (5.7%), pyrexia (4.9%), drug ineffective for unapproved indication (4.3%) and nausea (4.1%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Ethambutol hydrochloride was responsible.
How serious are the reports?
75.1% are marked serious by the reporter. Among the outcomes recorded, 10.5% of reports include death and 34.9% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
physician (37.3%), other health professional (24.7%) and consumer or non-health professional (15.7%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Ethambutol hydrochloride rising?
220 reports in the 12 months to June 2026, close to the 227 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Ethambutol hydrochloride was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Ethambutol hydrochloride?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Ethambutol hydrochloride as a suspect or interacting product; reports listing it only as a concomitant medication (1,403) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.