Pharmacologic class (EPC) · 2 drug pages

Human C1 esterase inhibitor: adverse event reports filed with FDA

3,328 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.

3,328
reports across the class: 0% of all reports; 86
reports, 12 months to June 2026: 198 in the 12 months before; 84%
marked serious by the reporter: 57.4% across all reports; 2
drugs with a page: brand and generic names counted separately

Human C1 esterase inhibitor 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 3,328 adverse event reports received by FDA, 0% of the database, from May 2009 to June 2026.

86 reports arrived in the 12 months to June 2026, down 57% from 198 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 84% of the class's reports are marked serious, 4.9% record death among the outcomes and 50.3% record hospitalisation, as reported.

Across the class the reactions recorded most often are hereditary angioedema (51%), inappropriate schedule of drug administration (12%) and prescribed overdose (11.9%). 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
CinryzeHuman c1-esterase inhibitor	brand	2,659	32	80.6%	Hereditary angioedema
Human c1-esterase inhibitor	generic	669	54	97.9%	Hereditary angioedema

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

Hereditary angioedema51%1,698
Inappropriate schedule of drug administrationthe medicine was taken at the wrong times12%399
Prescribed overdose11.9%396
Off label useused for a purpose or in a way not on the label11.6%387
Drug ineffectivethe medicine did not work as expected8.1%270
Product use issuea problem in how the product was used6%201
Pharyngeal oedemaswelling of the throat5.6%186
Inappropriate schedule of product administrationthe product was taken at the wrong times4.7%157
Product dose omission issuea dose was missed4.7%157
Dyspnoeashortness of breath4.5%149
Nauseafeeling sick4.3%142
Painpain, site not specified4%133
Headachehead pain3.9%129
Infusion related reactiona reaction during or soon after an infusion3.8%125
Fatiguetiredness3.7%124
Vomitingbeing sick3.6%121
Malaisegeneral feeling of being unwell3.5%117
Swellingswelling3.5%117
Angioedemadeep swelling of skin or mucous membranes3.5%116
Weight increasedweight gain3.2%108
Poor venous access3.2%105
Drug dose omissiona dose was missed3.1%104
Stressstress3.1%104
Pneumonialung infection3%99
Weight decreasedweight loss2.9%98

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

Death4.9%164

Life-threatening4.3%144

Hospitalisation (initial or prolonged)50.3%1,673

Disability2%67

Congenital anomaly1.4%47

Other serious52.1%1,734

Not serious16%531

Patient age

Under 20.1%3

2 to 111.1%36

12 to 172.7%89

18 to 4433.1%1,103

45 to 6421.9%728

65 to 744.4%146

75 and over2.2%73

Age not given34.6%1,150

Who reported

Physician20.4%678

Pharmacist12.8%425

Other health professional25.9%862

Lawyer0%0

Consumer or non-health professional38.3%1,275

Not given2.6%88

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 Human C1 esterase inhibitor reports

Which drugs are in the Human C1 esterase inhibitor class on this site?

Cinryze and Human c1-esterase inhibitor. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

3,328 reports through June 2026, 86 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?

hereditary angioedema (51%), inappropriate schedule of drug administration (12%), prescribed overdose (11.9%), off label use (11.6%) and drug ineffective (8.1%).

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.