Drugs › Vesicular monoamine transporter 2 inhibitor
Brand name · Tetrabenazine
Xenazine: adverse event reports filed with FDA
6,375 reports list it as a suspect or interacting product, 2006–2026. Class: Vesicular monoamine transporter 2 inhibitor.
- 6,375
- reports as suspect product
- 0% of all reports · about 314 a year
- 4
- reports, 12 months to June 2026
- 7 in the 12 months before
- 53%
- marked serious by the reporter
- 30.3% across the class
- 24.2%
- record death among outcomes, as reported
- 1,543 reports · not verified by FDA
Between March 2006 and March 2026, 6,375 adverse event reports received by FDA list the brand name Xenazine (tetrabenazine) as a suspect or interacting product. Reports that mention it only as a concomitant medication (108) are left out of every figure here.
In the 12 months to June 2026, 4 reports listed it, down 43% from 7 in 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 314 reports a year and 0% of the 20,646,523 reports in the database, and 20.2% of the reports for the vesicular monoamine transporter 2 inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.
The reactions recorded most often are death (19.7%), off label use (15.5%) and drug ineffective (7.7%). A report can list several reactions, so shares add to more than 100%; 482 different terms appear across these reports. Death is recorded in 19.7% of these reports, a larger share than in the median vesicular monoamine transporter 2 inhibitor drug (6.4%).
53% of the reports are marked serious by the reporter (30.3% across the class); 24.2% record death among the outcomes and 17.9% record hospitalisation, as reported. 62.7% of the reports came from consumers, and the largest patient age group is 45 to 64 (21.5%). 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 Xenazine reports recording the termmedian drug in vesicular monoamine transporter 2 inhibitor
- Deaththe patient died; cause not stated by this term19.7%1,256
- Off label useused for a purpose or in a way not on the label15.5%988
- Drug ineffectivethe medicine did not work as expected7.7%492
- Depressionlow mood6.8%431
- Somnolencedrowsiness6.1%392
- Fatiguetiredness4.9%315
- Hospitalisationadmission to hospital4.3%277
- Intentional product use issuedeliberate use not as intended4.3%271
- Falla fall4.1%262
- Insomniadifficulty sleeping3.9%248
- Drug administration errora mistake in giving the medicine3.7%233
- Anxietyanxiety3.4%218
- Drug dose omissiona dose was missed3.4%216
- Prescribed overdose3%189
- Tremorshaking2.9%186
- Condition aggravatedthe condition being treated got worse2.9%184
- Treatment noncompliancethe treatment was not taken as directed2.8%178
- Movement disorder2.7%174
- Dyskinesiainvoluntary movements2.5%161
- Suicidal ideationthoughts of suicide2.3%146
- Nauseafeeling sick2.2%140
- Feeling abnormalfeeling odd or not right2.1%137
- Gait disturbancedifficulty walking2.1%131
- Agitationrestlessness2%130
- Dysphagiadifficulty swallowing2%129
- Dizzinesslight-headedness or unsteadiness1.9%124
- Restlessnessrestlessness1.7%110
- Vomitingbeing sick1.7%108
- Pneumonialung infection1.7%106
- Malaisegeneral feeling of being unwell1.6%105
Top 30 of 482 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 3 drugs in the vesicular monoamine transporter 2 inhibitor 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 31,545 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. 98.2% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Huntington's disease | 2,427 | 38.1% |
| Dyskinesia | 550 | 8.6% |
| Chorea | 413 | 6.5% |
| Huntington's disease | 361 | 5.7% |
| Tardive dyskinesia | 329 | 5.2% |
| Huntington's chorea | 236 | 3.7% |
The indication field is filled in by the reporter and is often blank; shares are of all 6,375 reports.
In context
| Measure | Xenazine | Vesicular monoamine transporter 2 inhibitor | All reports |
|---|---|---|---|
| Reports as suspect product | 6,375 | 31,545 | 20,646,523 |
| Share of that pool | — | 20.2% | 0% |
| Reports, latest 12 months | 4 | — | 1,332,454 |
| Marked serious | 53% | 30.3% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 242 | 91 | 91 |
| Hospitalisation recorded, per 1,000 reports | 179 | 150 | 213 |
| Consumer-filed share | 62.7% | 49.3% | 45.8% |
| Top term, share of reports | Death 19.7% | median 6.4% | 4.1% |
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 vesicular monoamine transporter 2 inhibitor class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Ingrezza | brand | 24,265 | 1,137 | 22.6% |
| Tetrabenazine | generic | 905 | 70 | 76.1% |
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 Xenazine reports
How many adverse event reports has FDA received for Xenazine?
6,375 reports list Xenazine as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 4 of them arrived in the latest 12 months. Another 108 list it only as a concomitant medication.
What reactions are recorded in Xenazine reports?
death (19.7%), off label use (15.5%), drug ineffective (7.7%), depression (6.8%) and somnolence (6.1%). 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 Xenazine was responsible.
How serious are the reports?
53% are marked serious by the reporter. Among the outcomes recorded, 24.2% of reports include death and 17.9% 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?
consumer or non-health professional (62.7%), other health professional (14%) and physician (9.8%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Xenazine rising?
4 reports in the 12 months to June 2026, down 43% from 7 in 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 Xenazine 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 Xenazine?
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 Xenazine as a suspect or interacting product; reports listing it only as a concomitant medication (108) 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.