Pharmacologic class (EPC) · 2 drug pages

Vasopressin V2 receptor antagonist: adverse event reports filed with FDA

11,505 reports list a drug in this class as a suspect or interacting product, 2009–2026.

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.

11,505
reports across the class: 0.1% of all reports; 2,273
reports, 12 months to June 2026: 1,055 in the 12 months before; 76.5%
marked serious by the reporter: 57.4% across all reports; 2
drugs with a page: brand and generic names counted separately

Vasopressin V2 receptor antagonist is a pharmacologic class (an FDA Established Pharmacologic Class) with 2 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 11,505 adverse event reports received by FDA, 0.1% of the database, from July 2009 to June 2026.

2,273 reports arrived in the 12 months to June 2026, up 115% from 1,055 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 76.5% of the class's reports are marked serious, 18.8% record death among the outcomes and 25.2% record hospitalisation, as reported.

Across the class the reactions recorded most often are thirst (8.2%), death (8%) and product dose omission issue (6.2%). 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
Tolvaptan	generic	6,907	2,232	75.1%	Thirst
SamscaTolvaptan	brand	4,598	41	78.6%	Off label use

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

Thirst8.2%941
Deaththe patient died; cause not stated by this term8%921
Product dose omission issuea dose was missed6.2%716
Off label useused for a purpose or in a way not on the label6%686
Renal impairmentreduced kidney function5.7%657
Pollakiuriapassing urine more often4.6%525
Wrong technique in product usage processthe product was used in the wrong way4.3%500
Underdoseless than the intended dose4.2%481
Product use in unapproved indicationused for a purpose not on the label4.1%468
No adverse eventno adverse event was reported3.9%452
Polyuria3.8%432
Inappropriate schedule of product administrationthe product was taken at the wrong times3.7%429
Blood creatinine increasedraised creatinine, a kidney test3.5%399
Dehydrationdehydration3.5%398
Cardiac failureheart failure3.3%381
Hypernatraemia3.2%371
Fatiguetiredness3.2%369
Product use issuea problem in how the product was used3.2%369
Blood sodium decreased3%342
Nauseafeeling sick2.7%312
Blood urea increased2.4%273
Hepatic function abnormal2.3%270
Nocturia2.3%268
Dizzinesslight-headedness or unsteadiness2.3%266
Alanine aminotransferase increasedraised liver enzyme (ALT)2.3%260

Solid bar: share of all class reports. Hollow bar: the median share across the 2 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death18.8%2,159

Life-threatening2.7%316

Hospitalisation (initial or prolonged)25.2%2,894

Disability1.2%139

Congenital anomaly0%5

Other serious48.4%5,565

Not serious23.5%2,702

Patient age

Under 20.1%17

2 to 110.2%21

12 to 170.2%26

18 to 4413.5%1,552

45 to 6424.2%2,780

65 to 749.6%1,102

75 and over17.4%1,998

Age not given34.8%4,009

Who reported

Physician35.5%4,083

Pharmacist16.2%1,863

Other health professional14.8%1,705

Lawyer0%2

Consumer or non-health professional31.2%3,584

Not given2.3%268

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 Vasopressin V2 receptor antagonist reports

Which drugs are in the Vasopressin V2 receptor antagonist class on this site?

Tolvaptan and Samsca. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

11,505 reports through June 2026, 2,273 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?

thirst (8.2%), death (8%), product dose omission issue (6.2%), off label use (6%) and renal impairment (5.7%).

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.