Pharmacologic class (EPC) · 5 drug pages

Loop diuretic: adverse event reports filed with FDA

69,262 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.

69,262
reports across the class: 0.3% of all reports; 3,813
reports, 12 months to June 2026: 4,890 in the 12 months before; 93.4%
marked serious by the reporter: 57.4% across all reports; 5
drugs with a page: brand and generic names counted separately

Loop diuretic is a pharmacologic class (an FDA Established Pharmacologic Class) with 5 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 69,262 adverse event reports received by FDA, 0.3% of the database, from January 2004 to June 2026.

3,813 reports arrived in the 12 months to June 2026, down 22% from 4,890 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 93.4% of the class's reports are marked serious, 12.2% record death among the outcomes and 59.7% record hospitalisation, as reported.

Across the class the reactions recorded most often are acute kidney injury (12.9%), hypotension (8.7%) and dyspnoea (7.3%). 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
Furosemide	generic	48,738	2,973	95.7%	Acute kidney injury
LasixFurosemide	brand	12,591	244	86.2%	Dyspnoea
Torsemide	generic	5,282	431	94.7%	Dyspnoea
Bumetanide	generic	2,140	121	87.6%	Acute kidney injury
BumexBumetanide	brand	511	44	72.2%	Dyspnoea

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

Acute kidney injurysudden loss of kidney function12.9%8,933
Hypotensionlow blood pressure8.7%6,016
Dyspnoeashortness of breath7.3%5,027
Drug interactionan interaction between medicines6.4%4,433
Falla fall6%4,163
Drug ineffectivethe medicine did not work as expected6%4,132
Hyponatraemialow blood sodium5.8%4,038
Dehydrationdehydration5.1%3,528
Hypokalaemialow blood potassium4.9%3,407
Dizzinesslight-headedness or unsteadiness4.7%3,238
Fatiguetiredness4.2%2,911
Hyperkalaemiahigh blood potassium3.9%2,728
Off label useused for a purpose or in a way not on the label3.9%2,691
Condition aggravatedthe condition being treated got worse3.9%2,674
Diarrhoealoose or frequent stools3.7%2,566
Cardiac failureheart failure3.7%2,552
Oedema peripheralswelling of the legs, ankles or hands3.5%2,404
Nauseafeeling sick3.3%2,259
Astheniaweakness or lack of energy3.2%2,198
Syncopefainting3%2,105
Renal failure acute3%2,076
Painpain, site not specified3%2,070
Vomitingbeing sick2.9%2,011
Malaisegeneral feeling of being unwell2.8%1,916
Renal impairmentreduced kidney function2.7%1,875

Solid bar: share of all class reports. Hollow bar: the median share across the 5 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death12.2%8,465

Life-threatening9.1%6,270

Hospitalisation (initial or prolonged)59.7%41,371

Disability1.8%1,260

Congenital anomaly0.4%252

Other serious52.2%36,144

Not serious6.6%4,538

Patient age

Under 20.9%634

2 to 110.7%492

12 to 170.6%413

18 to 445.8%4,006

45 to 6416.2%11,241

65 to 7417.7%12,247

75 and over36%24,903

Age not given22.1%15,326

Who reported

Physician32.3%22,395

Pharmacist15.5%10,707

Other health professional32.8%22,727

Lawyer0.1%39

Consumer or non-health professional15.9%11,012

Not given3.4%2,382

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 Loop diuretic reports

Which drugs are in the Loop diuretic class on this site?

Furosemide, Lasix, Torsemide, Bumetanide and Bumex. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

69,262 reports through June 2026, 3,813 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?

acute kidney injury (12.9%), hypotension (8.7%), dyspnoea (7.3%), drug interaction (6.4%) and fall (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.