Pharmacologic class (EPC) · 12 drug pages

Topoisomerase inhibitor: adverse event reports filed with FDA

86,440 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.

86,440
reports across the class: 0.4% of all reports; 6,772
reports, 12 months to June 2026: 7,055 in the 12 months before; 96.8%
marked serious by the reporter: 57.4% across all reports; 12
drugs with a page: brand and generic names counted separately

Topoisomerase inhibitor is a pharmacologic class (an FDA Established Pharmacologic Class) with 12 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 86,440 adverse event reports received by FDA, 0.4% of the database, from January 2004 to June 2026.

6,772 reports arrived in the 12 months to June 2026, close to the 7,055 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 96.8% of the class's reports are marked serious, 23.1% record death among the outcomes and 36.2% record hospitalisation, as reported.

Across the class the reactions recorded most often are febrile neutropenia (10.7%), off label use (10.5%) and neutropenia (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
Etoposide	generic	62,291	4,749	97.9%	Febrile neutropenia
Irinotecan hydrochloride	generic	6,095	800	96.6%	Diarrhoea
Mitoxantrone	generic	4,065	132	98.8%	Febrile neutropenia
Topotecan	generic	3,668	187	96.6%	Neutropenia
CamptosarIrinotecan hydrochloride	brand	2,535	110	85.4%	Diarrhoea
OnivydeIrinotecan hydrochloride	brand	1,911	614	92%	Diarrhoea
HycamtinTopotecan	brand	1,526	14	79.2%	Death
Mitoxantrone hydrochloride	generic	1,213	39	97.1%	Febrile neutropenia
VePesidEtoposide	brand	900	20	96.7%	Off label use
Topotecan hydrochloride	generic	867	36	96.8%	Febrile neutropenia
Etoposide phosphate	generic	747	63	96.5%	Disease progression
EtopophosEtoposide phosphate	brand	622	8	84.2%	Product storage error

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

Febrile neutropeniafever with low white blood cells10.7%9,257
Off label useused for a purpose or in a way not on the label10.5%9,042
Neutropenialow neutrophils, a type of white blood cell7.1%6,150
Disease progressionthe disease advanced6.1%5,256
Drug ineffectivethe medicine did not work as expected5.5%4,779
Thrombocytopenialow platelets5.5%4,763
Pyrexiafever4.9%4,263
Anaemialow red blood cells4.7%4,056
Diarrhoealoose or frequent stools4.6%3,974
Nauseafeeling sick4.1%3,568
Product use in unapproved indicationused for a purpose not on the label4.1%3,519
Sepsisa severe body-wide response to infection4%3,480
Deaththe patient died; cause not stated by this term3.7%3,220
Vomitingbeing sick3.7%3,220
Pancytopenialow counts of all blood cells3.7%3,196
Malignant neoplasm progression3.1%2,681
Pneumonialung infection3.1%2,670
Myelosuppression2.9%2,548
Mucosal inflammation2.8%2,438
Infectionan infection, type not specified2.6%2,209
Fatiguetiredness2.5%2,172
Dyspnoeashortness of breath2.2%1,885
Septic shockshock arising from infection2.1%1,806
White blood cell count decreasedlow white cell count2%1,760
Acute myeloid leukaemia2%1,747

Solid bar: share of all class reports. Hollow bar: the median share across the 12 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death23.1%19,956

Life-threatening9.2%7,983

Hospitalisation (initial or prolonged)36.2%31,265

Disability1.3%1,137

Congenital anomaly0.2%163

Other serious62.9%54,355

Not serious3.2%2,724

Patient age

Under 22.5%2,146

2 to 118.6%7,436

12 to 175.3%4,596

18 to 4414.5%12,507

45 to 6422.3%19,297

65 to 7412.7%11,019

75 and over4.7%4,072

Age not given29.3%25,367

Who reported

Physician38.5%33,249

Pharmacist4.5%3,851

Other health professional44.9%38,786

Lawyer0.1%50

Consumer or non-health professional6.8%5,883

Not given5.3%4,621

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 Topoisomerase inhibitor reports

Which drugs are in the Topoisomerase inhibitor class on this site?

Etoposide, Irinotecan hydrochloride, Mitoxantrone, Topotecan, Camptosar and Onivyde and 6 more. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

86,440 reports through June 2026, 6,772 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?

febrile neutropenia (10.7%), off label use (10.5%), neutropenia (7.1%), disease progression (6.1%) and drug ineffective (5.5%).

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.