Icatibant dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Icatibant is a lab-made peptide that blocks bradykinin.
Evidence grade for Icatibant: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 5 completed trials, 306 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 306
- Human studies
- 5
- Found nothing
- 2
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA approved 25 August 2011 (FIRAZYR, NDA 022150) for sudden attacks of hereditary angioedema in adults, an inherited condition that causes bouts of severe swelling. Given as a shot under the skin. Listed as Prescription when we checked the FDA drug database (Drugs@FDA) on 11 September 2026, along with 6 generic icatibant acetate products approved between 2019 and 2024. It treats an attack once it starts. It does not prevent attacks, and it is not approved for swelling caused by ACE inhibitors, a type of blood pressure drug.
4 effects reported, 2 unwanted, 2 wanted, by people using it, not a trial
Goal pages: Ageing and longevity
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Icatibant is a lab-made peptide that blocks bradykinin. It is a shot for sudden attacks of hereditary angioedema, an inherited swelling disorder. It stops an attack that has started. It does not prevent the next one.
What people take it for
- Stopping a hereditary angioedema attack.
- Doctors have tried it for swelling caused by blood pressure pills.
What studies in people showed
The biggest study was not in its approved use. In 121 people with swelling from blood pressure pills, it did no better than a dummy shot. Both groups were ready to go home in about 4 hours. For the inherited disorder, 74 people got relief in about 2 hours on icatibant, against 12 hours on tranexamic acid tablets. In 56 people, it was 2.5 hours against 4.6 hours on a dummy shot, a gap that could be chance. Far fewer on icatibant needed rescue medicine. In 73 people with COVID-19 pneumonia, it missed its main goal.
What people report
Reports, not study results
The good
- In the inherited disorder, relief came in about 2 hours, against 12 hours on tranexamic acid tablets.
- Far fewer people on icatibant needed rescue medicine than on the dummy shot.
The bad
- For swelling from blood pressure pills, the larger study found no benefit.
- It does nothing to prevent attacks.
Where these come from: No user reports. These come from the FAST-1 and FAST-2 studies and the blood pressure pill swelling studies on this page.
My bottom line
If you have the inherited disorder, this is a real tool your specialist can prescribe. For anything else, the evidence says no.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Icatibant has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Living longerno headcount stated · 1 study · 1 found nothing
35 of the 36 indexed goals have no study of any kind behind Icatibant
No study in people, animals or cells on this page reports a result for these. That does not prove Icatibant does nothing for them. It does mean anything you have heard about Icatibant and one of these did not come from a study cited here.
Show full evidence
What is Icatibant?
Icatibant is a lab-made peptide that blocks bradykinin. It was approved in 2011 as a shot for sudden attacks of hereditary angioedema, an inherited swelling disorder. In one large final-stage study it worked much faster than tranexamic acid tablets. In the other, it did not clearly beat a dummy shot. For swelling caused by blood pressure pills, the larger study against a dummy shot found no benefit.
Icatibant is a lab-made peptide, 10 building blocks long. It uses unnatural building blocks so the body's enzymes cannot chew it up. That lets a peptide blocker survive as a shot under the skin. It blocks the bradykinin B2 receptor. Bradykinin is what causes the swelling in hereditary angioedema, an inherited swelling disorder. So blocking that receptor stops an attack.
Approval rests on two large final-stage studies. In FAST-2, 74 people having an attack got either one 30 mg shot of icatibant or tranexamic acid tablets. Real relief came in a typical 2.0 hours on icatibant, against 12.0 hours on the tablets. In FAST-1, 56 people got icatibant or a dummy shot. Relief came in 2.5 hours against 4.6 hours, a gap that could have been chance. 3 people on icatibant and 13 on the dummy shot needed rescue medicine. The authors argued that early rescue medicine blurred the comparison. Jerini, the company that developed it, paid for both.
The drug has also been tried for other uses, and those results are mixed to negative. The largest was a 2017 study of swelling caused by ACE inhibitor blood pressure pills. It gave 121 people icatibant or a dummy shot and found no difference at all. Both groups were ready to go home in a typical 4.0 hours. A smaller 2015 study of 27 people with the same problem looked better. Swelling cleared in 8.0 hours on icatibant against 27.1 hours on a steroid plus an antihistamine. Shire paid for that one. In COVID-19 pneumonia, a study of 73 people in hospital, where everyone knew who got what, missed its main goal.
We checked the US drug records on 11 September 2026. FIRAZYR, NDA 022150, from Takeda Pharms USA, was first approved on 25 August 2011 and is listed as prescription. Six generic icatibant acetate injections are also listed as prescription. They come from Teva (2019), Hansoh, Fresenius Kabi and Cipla (2020), Eugia (2023) and Alembic (2024).
How does Icatibant work?
In people, icatibant blocks the bradykinin B2 receptor. In hereditary angioedema, people are short of a protein called C1 inhibitor. That lets an enzyme called kallikrein run wild and make too much bradykinin. Bradykinin makes blood vessels leaky, and that causes the swelling. Blocking B2 removes the signal that causes the swelling. The same logic applies to swelling from ACE inhibitors, where the pill raises bradykinin. Icatibant treats an attack that has already started. It does nothing to prevent the next one.
What have studies in people found about Icatibant?
Strong for the approved use, and clearly mixed outside it. There are two large final-stage studies in hereditary angioedema. There are two studies in swelling from ACE inhibitors that point in opposite directions. And there is one study in COVID-19 that missed its main goal.
- ACE inhibitor swelling, 2017: 121 people at 31 hospitals got icatibant or a dummy shot. Both groups were ready to go home in a typical 4.0 hours. No other measure and no subgroup favoured icatibant.
- FAST-2: 74 people. Real relief came in a typical 2.0 hours on icatibant against 12.0 hours on tranexamic acid. The maker paid.
- COVID-19 pneumonia, 2023: 73 people in hospital, and everyone knew who got what. It missed its main goal (73.0 against 55.6 percent, a gap that could be chance). A 28 day measure and the death count favoured icatibant. But the study was not built or sized to test deaths.
- FAST-1: 56 people against a dummy shot, 2.5 against 4.6 hours. That gap could be chance. 13 people on the dummy shot took rescue medicine, against 3 on icatibant.
- ACE inhibitor swelling, 2015: 27 people counted. Swelling cleared in a typical 8.0 hours on icatibant against 27.1 hours on standard treatment. The comparison was a steroid and an antihistamine, not a dummy.
What this does not tell you: The hereditary angioedema evidence is about how fast one attack clears. It is not about how often attacks happen, because icatibant does not prevent them. The two studies of ACE inhibitor swelling cannot both be right. The smaller one compared against steroids and antihistamines. The larger one compared against a dummy shot and found nothing, and that is the harder test. The COVID-19 study had 73 people, and everyone knew who got what. So its extra findings, including deaths, are only ideas to test.
The state of the research
Icatibant is the payoff of the bradykinin story on this site. Bradykinin itself cannot be used as a drug, but its blocker became one. It also shows that a peptide can be built around its own weak spot. Natural peptides are destroyed by the body's enzymes in minutes. Icatibant is built with unnatural building blocks and lasts long enough to be a shot people give themselves. Half of it is gone in about 1.4 hours on average.
The push into new uses is worth watching honestly. Swelling from ACE inhibitors is far more common than the inherited kind. It has no approved treatment, and the same signal drives it. So trying icatibant there made sense. One study against standard treatment favoured it. The larger study against a dummy shot found nothing. The review of the field reports exactly that split. The COVID-19 study follows the same pattern. A sensible idea missed its main goal but had some good-looking extra numbers. Neither is a reason to widen the drug's use, and this page does not.
Six generic icatibant products have been approved in the United States since 2019. That changes the money side. There is now little reason for anyone to fund more studies of an off-patent peptide in a new use.
The evidence, in charts
Fig. 1a · how many people
306people, across 4 studies in people cited here
| Study | People | Share |
|---|---|---|
| Journal of Allergy and Clinical Immunology: In Practice 2017 | 121 | 40% |
| FAST-1, ClinicalTrials.gov 2010 | 84 | 27% |
| New England Journal of Medicine 2010 | 74 | 24% |
| New England Journal of Medicine 2015 | 27 | 9% |
Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 1 more study in people gives no headcount and is not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
5 of 8 sources here are studies in people. The rest are not.
- Study in people · done in people563%
- Review of studies · sums up other studies338%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 6 different years, 2004 to 2023, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Approved
UK
Prescription
AU
Prescription
CA
Prescription
Approved in 1 of 4, by prescription in 3, not approved in 0. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 5 · what the molecule is
- Kind of compound
- Peptide
- Molecule weight
- Not on file
- Half-life
- About 1.4 hoursShort, 1 to 6 hours
- Chain length
- None on file
No amino acid sequence is on file for Icatibant, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2010Icatibant, a new bradykinin-receptor antagonist, in hereditary angioedema
For the inherited form of this swelling the drug works, and one of the two trials was clearer than the other. 74 people were compared against a tranexamic acid tablet, and relief came in about 2 hours against about 12. 56 people were compared against a dummy injection, about 2.5 hours against about 4.6, a gap small enough to be chance. Far fewer on the drug needed rescue treatment. No serious side effects were blamed on it. Jerini, the developer, paid for both.
Two phase 3 trials. FAST-2 randomised 74 people against oral tranexamic acid: median time to clinically significant relief 2.0 versus 12.0 hours (p < 0.001). FAST-1 randomised 56 people against placebo: 2.5 versus 4.6 hours (p = 0.14), with 3 icatibant and 13 placebo recipients needing rescue medication. No icatibant-related serious adverse events. Funded by Jerini.
- Study in people2015A randomized trial of icatibant in ACE-inhibitor-induced angioedema
In this small trial the drug cleared drug induced swelling far faster than the standard treatment. 27 people got either icatibant or a steroid and antihistamine through a drip, and nobody involved knew which. Swelling resolved in about 8 hours against about 27. Five of 13 on icatibant were clear within 4 hours, against none of 14 on the standard treatment. Shire, which sells icatibant, funded it. Read it against the larger trial on this page, which found nothing.
Phase 2, double-blind, double-dummy: 27 patients analysed per protocol. Median time to complete resolution 8.0 hours with icatibant versus 27.1 hours with intravenous prednisolone plus clemastine (p = 0.002). Complete resolution within 4 hours in 5 of 13 versus 0 of 14 (p = 0.02). Funded by Shire.
- Study in people2017Randomized Trial of Icatibant for Angiotensin-Converting Enzyme Inhibitor-Induced Upper Airway Angioedema
The bigger and fairer test of the same idea found nothing at all. 121 adults with upper airway swelling caused by a blood pressure pill took part at 31 hospitals in four countries. Half got icatibant and half got a dummy shot. Time to being ready to go home was the same in both groups, about 4 hours. Time to symptom relief was the same. Nothing else measured differed either, in any group looked at. This clean negative outweighs the small positive one.
121 adults at 31 centres in 4 countries randomised to icatibant 30 mg or placebo. No difference in time to meeting discharge criteria (median 4.0 hours in both arms, p = 0.63), no difference in time to symptom relief (2.0 versus 1.6 hours, p = 0.57), and no difference in any secondary endpoint or prespecified subgroup. A clean null result in the larger, placebo-controlled test.
- Study in people2023Three-Day Icatibant on Top of Standard Care in Patients With Coronavirus Disease 2019 Pneumonia: A Randomized, Open-Label, Phase 2, Proof-of-Concept Trial
The main thing this study set out to show, it did not show. 73 people in hospital with COVID-19 pneumonia got icatibant on top of usual care, or usual care alone. Recovery by day 10 was better on the drug, but not by enough to count. By 28 days, everyone on icatibant had recovered against about 83 in every hundred on usual care. 6 people on usual care died, against none on the drug. Everybody knew who was getting what.
73 inpatients with COVID-19 pneumonia randomised to icatibant plus standard care or standard care alone. The primary endpoint, clinical response at day 10 or discharge, was 73.0 versus 55.6 percent and did not reach significance (p = 0.115). The secondary endpoint at 28 days favoured icatibant (100 versus 83.3 percent, p = 0.011) and no deaths occurred on icatibant versus 6 on control. Open-label and small, with the primary endpoint missed.
- Study in people2010Subcutaneous Treatment With Icatibant for Acute Attacks of Hereditary Angioedema (FAST-1)
This is the registry entry for the trial against a dummy injection, and it carries no results. It records 84 people enrolled, the study completed, and Shire as the sponsor. The companion trial against a tranexamic acid tablet enrolled 85 and is also listed as completed. What those trials found is published in a medical journal, not here.
Registry record for the placebo-controlled phase 3: 84 participants enrolled, completed, lead sponsor Shire. The companion trial against tranexamic acid, NCT00500656, enrolled 85 and is also completed.
- Review of studies2018Pharmacotherapy for Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema: A Systematic Review
A review of 5 studies covering 218 cases of swelling from blood pressure pills. One of 2 icatibant studies showed faster improvement than steroids plus antihistamines, and the other did not. Two other drugs, ecallantide and C1 inhibitor, did no better than the comparison.
5 studies covering 218 cases. One of the 2 icatibant studies showed faster improvement than corticosteroids plus antihistamines and the other did not; ecallantide and C1 inhibitor replacement showed no significant benefit over control.
- Review of studies2018Icatibant for the treatment of hereditary angioedema with C1-inhibitor deficiency in adolescents and in children aged over 2 years
A review of the evidence in children and teenagers. It sums up the dosing and safety data for use below adult age.
Review of the paediatric and adolescent evidence supporting use below adult age, summarising the dosing and safety data available in that population.
- Review of studies2004Bradykinin receptor ligands: therapeutic perspectives
A review of the kinin receptors behind icatibant, written before it was approved. It explains why blocking B2 became the way to build a drug.
Review of the kinin receptor pharmacology behind icatibant, written before its approval, describing why B2 antagonism became the drug development route.
Where to buy Icatibant
Icatibant is an approved medicine. The approved product comes from a pharmacy, with a prescription. The vials below are sold “for research” and are not the approved drug.
1 seller lists Icatibant in our latest read. They are ranked by trust score, then by archive rating, then by certificate tier, then by the lowest price per milligram. Archive evidence is counted before source-backed. Each path is out of 4, and the two are not added. A higher price does not raise the score. The letter is the certificate chip. 0 of them have a published certificate that names Icatibant.
Some seller links may pay this site when you buy through them. A payment never changes a seller's tier or rank, and no seller has a say in any page.
| Seller | Trust score | Vial sizes | From, per mg | Certificate for Icatibant | Seller link |
|---|---|---|---|---|---|
| Boston Molecules | 28 InsufficientSource-backed 1 of 4. Archive evidence 1 of 4.C | 10 mg | $81.0 | None found for Icatibant | View |
- LC Lab-confirmed: the issuing laboratory echoed this certificate back
- A Current certificate, independent laboratory named, laboratory not yet checked
- B Certificate published, but no laboratory link, older than a year, or the laboratory did not recognise the published lookup
- C No certificate could be read
Every listing and vial size for Icatibant · How the trust score is counted
Sellers named on the price pages are ranked by certificate tier, then price, and any affiliate income is disclosed there. Naming a seller is not a recommendation to buy or use anything.
Common questions
Has Icatibant been tested in people?
Yes. 306 people given it across 5 completed trials cited here, 2 of which found nothing. Icatibant is a lab-made peptide that blocks bradykinin.
What is the Icatibant dosage?
Approved medicine. No human dose established for unlabelled uses. Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose. FDA approved 25 August 2011 (FIRAZYR, NDA 022150) for sudden attacks of hereditary angioedema in adults, an inherited condition that causes bouts of severe swelling. Given as a shot under the skin. Listed as Prescription when we checked the FDA drug database (Drugs@FDA) on 11 September 2026, along with 6 generic icatibant acetate products approved between 2019 and 2024. It treats an attack once it starts. It does not prevent attacks, and it is not approved for swelling caused by ACE inhibitors, a type of blood pressure drug.
Is Icatibant FDA-approved?
FDA approved 25 August 2011 (FIRAZYR, NDA 022150) for sudden attacks of hereditary angioedema in adults, an inherited condition that causes bouts of severe swelling. Given as a shot under the skin. Listed as Prescription when we checked the FDA drug database (Drugs@FDA) on 11 September 2026, along with 6 generic icatibant acetate products approved between 2019 and 2024. It treats an attack once it starts. It does not prevent attacks, and it is not approved for swelling caused by ACE inhibitors, a type of blood pressure drug.
What is icatibant approved for?
Sudden attacks of hereditary angioedema, an inherited swelling disorder, in adults. It is a shot under the skin. It was approved in the United States on 25 August 2011 and is listed as prescription, along with 6 generics approved between 2019 and 2024.
How fast does it work?
In the two large studies, real relief came in a typical 2.0 hours, against 12.0 hours on tranexamic acid tablets. Against a dummy shot, it was 2.5 hours against 4.6 hours. Only the tablet comparison was a clear win.
Does it work for angioedema caused by blood pressure drugs?
The evidence clashes. A 27 patient study found swelling cleared in 8.0 hours, against 27.1 hours on steroids and antihistamines. A larger 121 patient study against a dummy shot found no difference at all, a typical 4.0 hours in both groups. It is not approved for this use.
Does icatibant prevent angioedema attacks?
No. It treats an attack that has already started. Preventing attacks of hereditary angioedema uses different medicines. Nothing in the icatibant studies tested prevention.