Icatibant is a synthetic peptidomimetic drug that is used in the treatment of acute attacks of hereditary angioedema (HAE) in adults. It is designed to function as a selective and competitive antagonist of the bradykinin B2 receptor.

Hereditary angioedema (HAE) is a rare genetic disorder that is characterized by episodes of swelling in different parts of the body including the hands, feet, face, and airways. It can be potentially life-threatening, especially when the swelling affects the airways.

Icatibant (Firazyr) inhibits the binding of bradykinin to its receptors alleviating the acute symptoms of angioedema such as facial and lips swelling and airway edema. C-1 esterase is deficient or dysfunctional in patients with hereditary angioedema that results in the production of uncontrolled release of bradykinin.

Icatibant Uses:

• Hereditary angioedema:
  • It is indicated for aborting the acute attacks of hereditary angioedema (HAE).
• Off-Label Use of Icatibant in Adults:
  • It may be used in the treatment of severe or life-threatening angioedema induced by an angiotensin-converting enzyme inhibitor.

Icatibant (Firazyr) Dose in Adults:

Icatibant (Firazyr) Dose in the treatment of hereditary angioedema:

• The dose is an injection under the skin of 30 mg.
• If it doesn't work well or symptoms come back, you can take it again every 6 hours.
• But, don't take more than 90 mg in one day.

Icatibant (Firazyr) Dose in the treatment of severe or life-threatening Angiotensin-converting enzyme inhibitor–induced angioedema:

• The dose is an injection under the skin of 30 mg.
• If symptoms get worse after 6 hours, another 30 mg injection can be given.

Note:

• It's best to use Icatibant within the first 6 hours of an angioedema attack, when the swelling is still getting worse.
• If needed, some people also get an IV treatment (not in the US) with the second dose of Icatibant.

Icatibant (Firazyr) Dose in Childrens:

Icatibant (Firazyr) Dose in the treatment of Hereditary angioedema (HAE): 

For treating Hereditary angioedema (HAE) in kids older than 2 and teenagers:

• They get a shot under the skin of 0.4 mg for every kg of their weight, but not more than 30 mg in one shot.
• This is based on a study done with 32 young patients.

Pregnancy Risk Factor C

• There were some side effects seen when Icatibant was given to pregnant animals.
• There's not a lot of information about its safety for pregnant women.
• So, if a pregnant woman needs treatment for Hereditary angioedema (HAE), doctors suggest using other medicines instead.

Icatibant use during breastfeeding:

• We don't know if Icatibant goes into breast milk.
• The maker of the drug says to be careful if giving it to women who are breastfeeding.
• If a breastfeeding woman needs treatment for HAE, it's better to use different medicines.

Icatibant (Firazyr) Dose in Kidney Disease:

• You don't need to change the dose for people with kidney problems.
• Even though it hasn't been fully studied, the body doesn't get rid of icatibant through the kidneys, so it shouldn't build up in people with these problems.

Icatibant (Firazyr) Dose in Liver disease:

Adjustment in the dose is not necessary for patients with liver disease.

Common Side Effects of Icatibant:

• Local:
  • Injection site reaction

Less Common Side Effects of Icatibant:

• Central nervous system:
  • Dizziness
• Hepatic:
  • Increased serum transaminase
• Miscellaneous:
  • Fever

Contraindication to Icatibant (Firazyr):

• The manufacturer doesn't list any reasons not to use the drug.
• But in Canada, they say don't use it if you're allergic to icatibant acetate or anything else in the drug. This warning isn't on the US label.

Warnings and precautions

Obstructing the airway:

• When someone has a severe HAE attack in their throat, it might block their breathing.
• If this happens, even if they take icatibant, they should go to the hospital right away.

CNS effects

• This drug might make you feel drowsy or slow your thinking.
• So, if you take it, be careful with activities like driving or using machines.

Icatibant (Firazyr): Drug Interaction

Monitoring parameters:

• The drug helps with symptoms, but if someone has throat problems or trouble breathing, they need to see a doctor right away, even if they take icatibant.

How to administer Icatibant (Firazyr)?

SubQ:

• This medicine is for an injection under the skin.
• Patients can give it to themselves when they feel an HAE attack starting.
• Inject it slowly, over half a minute, into the belly using the given needle.
• Choose a spot 2 to 4 inches below the belly button and away from scars.
• Don't inject where it's bruised, swollen, or hurts.

Mechanism of action of Icatibant (Firazyr):

• Icatibant blocks a specific receptor called bradykinin B.
• People with HAE have a problem with a certain protein, leading to more bradykinin.
• Too much bradykinin can cause swelling, redness, and pain.
• Icatibant stops bradykinin from working too much, which helps treat the symptoms during an attack.

Effectiveness:

• It starts working pretty fast, with symptoms decreasing by half in about 2 hours.
• The effects last for about 6 hours.

How it spreads in the body (Distribution):

• For kids older than 2: It spreads out in the body at about 0.39 liters for every kilogram of their weight.
• For teenagers: It's 0.44 liters per kilogram.
• For adults: It's spread across 29 liters.

How the body processes it (Metabolism & Excretion):

• The body breaks it down using enzymes.
• Only a tiny bit (less than 10%) leaves the body unchanged through urine.

How much gets into the body (Bioavailability):

• About 97% of the drug actually starts working in the body.

How long it stays in the body (Half-life):

• For kids older than 2: It's around for about 0.8 hours.
• For teenagers: About 1.34 hours.
• For adults: About 1.4 hours.

Time it takes to reach maximum effect (Time to peak):

• For kids older than 2: It peaks in about 0.42 hours.
• For teenagers: It peaks in about 0.55 hours.
• For adults: It peaks in about 0.75 hours.

International Brand Names of Icatibant:

• Firazyr

Icatibant Brand Names in Pakistan:

Not Available.