Pharmacologic class (EPC) · 3 drug pages

Vesicular monoamine transporter 2 inhibitor: adverse event reports filed with FDA

31,545 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

31,545
reports across the class: 0.2% of all reports; 1,211
reports, 12 months to June 2026: 1,081 in the 12 months before; 30.3%
marked serious by the reporter: 57.4% across all reports; 3
drugs with a page: brand and generic names counted separately

Vesicular monoamine transporter 2 inhibitor is a pharmacologic class (an FDA Established Pharmacologic Class) with 3 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 31,545 adverse event reports received by FDA, 0.2% of the database, from September 2004 to June 2026.

1,211 reports arrived in the 12 months to June 2026, up 12% from 1,081 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 30.3% of the class's reports are marked serious, 9.1% record death among the outcomes and 15% record hospitalisation, as reported.

Across the class the reactions recorded most often are drug ineffective (10.7%), somnolence (9.1%) and death (7.1%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
IngrezzaValbenazine	brand	24,265	1,137	22.6%	Drug ineffective
XenazineTetrabenazine	brand	6,375	4	53%	Death
Tetrabenazine	generic	905	70	76.1%	Drug ineffective

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Drug ineffectivethe medicine did not work as expected10.7%3,389
Somnolencedrowsiness9.1%2,865
Deaththe patient died; cause not stated by this term7.1%2,228
Fatiguetiredness6.3%1,999
Tremorshaking5.6%1,752
Off label useused for a purpose or in a way not on the label5.5%1,747
Tardive dyskinesiainvoluntary repetitive movements4.7%1,491
Falla fall4.4%1,394
Dizzinesslight-headedness or unsteadiness3.4%1,069
Dyskinesiainvoluntary movements3.3%1,035
Hospitalisationadmission to hospital3%944
Drooling3%943
Depressionlow mood2.9%921
Anxietyanxiety2.8%888
Therapeutic product effect decreased2.8%876
Insomniadifficulty sleeping2.6%805
Nauseafeeling sick2.4%761
Parkinsonism2.2%699
Balance disorderproblems with balance2.1%648
Adverse drug reactiona harmful or unpleasant reaction reported to a medicine1.9%608
Feeling abnormalfeeling odd or not right1.9%601
Gait disturbancedifficulty walking1.9%592
Restlessnessrestlessness1.8%579
Therapeutic product effect incomplete1.8%555
Headachehead pain1.7%535

Solid bar: share of all class reports. Hollow bar: the median share across the 3 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death9.1%2,861

Life-threatening0.6%190

Hospitalisation (initial or prolonged)15%4,732

Disability0.4%116

Congenital anomaly0%2

Other serious9.4%2,953

Not serious69.7%21,997

Patient age

Under 20%12

2 to 110.5%168

12 to 170.6%184

18 to 446.1%1,929

45 to 6418%5,684

65 to 7410.6%3,335

75 and over5.6%1,767

Age not given58.5%18,466

Who reported

Physician12.5%3,932

Pharmacist4.1%1,281

Other health professional22.4%7,066

Lawyer0%9

Consumer or non-health professional49.3%15,553

Not given11.7%3,704

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Vesicular monoamine transporter 2 inhibitor reports

Which drugs are in the Vesicular monoamine transporter 2 inhibitor class on this site?

Ingrezza, Xenazine and Tetrabenazine. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

31,545 reports through June 2026, 1,211 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

drug ineffective (10.7%), somnolence (9.1%), death (7.1%), fatigue (6.3%) and tremor (5.6%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. 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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.