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C1 Inhibitor (Human)

Medically reviewed by Last updated on May 1, 2023.


(cee won in HIB i ter HYU man)

Index Terms

  • C1 Esterase Inhibitor
  • C1-INH
  • C1-Inhibitor
  • Human C1 Inhibitor

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Kit, Intravenous:

Berinert: 500 units

Solution Reconstituted, Intravenous [preservative free]:

Cinryze: 500 units (1 ea)

Solution Reconstituted, Subcutaneous:

Haegarda: 2000 units (1 ea); 3000 units (1 ea)

Brand Names: U.S.

  • Berinert
  • Cinryze
  • Haegarda

Pharmacologic Category

  • Blood Product Derivative
  • C1 Esterase Inhibitor


C1 inhibitor, one of the serine proteinase inhibitors found in human blood, plays a role in regulating the complement and intrinsic coagulation (contact system) pathway, and is also involved in the fibrinolytic and kinin pathways. C1 inhibitor therapy in patients with C1 inhibitor deficiency, such as HAE, is believed to suppress contact system activation via inactivation of plasma kallikrein and factor XIIa, thus preventing bradykinin production. Unregulated bradykinin production is thought to contribute to the increased vascular permeability and angioedema observed in HAE.


Berinert: Vss: Children and Adolescents: (6 to 13 years, n=5): 0.02 L/kg (range: 0.017 to 0.026 L/kg); Adults: 0.018 L/kg (range: 0.011 to 0.028 L/kg)

Haegarda: Vd: Adolescents and Adults: 0.05 L/kg

Onset of Action

Berinert: Onset of symptom relief: Median: 15 minutes per attack; Cinryze: Pediatric patients 6 to 17 years: Median: 30 minutes per attack; for the majority of patient unequivocal symptom relief reported within 1 hour (range: 15 to 135 minutes) (Lumry 2013)

Cinryze: Increased plasma C1 inhibitor levels observed ~1 hour or less

Time to Peak

Cinryze: ~4 hours; Haegarda: 59 hours

Duration of Action

Time to complete resolution of HAE symptoms: Berinert: Median: 8.4 hours

Half-Life Elimination


Children and Adolescents (6 to 13 years, n=5): 22 hours (range: 20 to 24 hours)

Adults (following a single dose): 22 hours (range: 17 to 24 hours)

Cinryze: Adults: 56 hours (range: 11 to 108 hours)

Haegarda: Adolescents and Adults: 69 hours

Special Populations: Children

Cinryze: Compared to adults, children 7 to 11 years of age showed a 30% higher mean AUC and Cmax at a 1,000 unit dose level

Use: Labeled Indications

Hereditary angioedema:

Berinert: Treatment of acute abdominal, facial, or laryngeal attacks of hereditary angioedema (HAE) in adults and pediatric patients.

Cinryze: Routine prophylaxis against angioedema attacks in adults, adolescents, and pediatric patients ≥6 years of age with HAE.

Haegarda: Routine prophylaxis against angioedema attacks in patients 6 years of age and older with HAE.


History of anaphylactic or life-threatening hypersensitivity reactions to C1 inhibitor (human) or any component of the formulation

Dosing: Adult

Hereditary angioedema (HAE) attacks, prophylaxis: Note: Have on-demand therapy available for all patients (breakthrough attacks may occur) (WAO/EEACI [Maurer 2018])

Guideline recommendations:

Short-term/pre-procedural prophylaxis (off-label dose): Cinryze: IV: 20 units/kg or 1,000 units as close as possible to the start of the procedure (WAO/EEACI [Maurer 2018])

Long-term prophylaxis (off-label dose): Haegarda: SubQ: 40 or 60 units/kg twice weekly; adjust dose based on patient response. Note: SubQ administration may provide more convenient administration as well as improved steady state plasma concentrations (compared to IV administration) (WAO/EEACI [Maurer 2018]; Longhurst 2017)

Manufacturer’s labeling:

Long-term prophylaxis:

Cinryze: IV: 1,000 units every 3 to 4 days; if response is not adequate, doses up to 2,500 units (≤100 units/kg) every 3 or 4 days may be considered based on individual patient response.

Haegarda: SubQ: 60 units/kg every 3 or 4 days.

HAE attacks (abdominal, facial or laryngeal), treatment (Berinert): IV: 20 units/kg

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Products are not interchangeable.

Hereditary angioedema (HAE) attacks; routine prophylaxis:

Cinryze: Note: If used for preprocedural prophylaxis, administer as close as possible to the beginning of the procedure (WAO/EEACI [Maurer 2018]).

Children 6 to 11 years: IV: 500 units every 3 to 4 days; if inadequate response, may increase dose to 1,000 units every 3 to 4 days (Lumry 2013)

Children ≥12 years and Adolescents: IV: 1,000 units every 3 to 4 days; if an adequate response is not achieved, doses up to 2,500 units (≤100 units/kg/dose) every 3 to 4 days may be considered

Haegarda: Children ≥6 years and Adolescents: SubQ: 60 units/kg/dose every 3 or 4 days. A lower dose of 40 units/kg/dose has been studied; however, it appears to have a lower response rate (Longhurst 2017); Note: For long-term prophylaxis, SubQ administration may provide greater convenience as well as improved steady-state plasma concentrations (compared to IV administration) (Longhurst 2017; WAO/EEACI [Maurer 2018])

Hereditary angioedema (HAE) attacks (abdominal, facial or laryngeal); treatment:

Berinert: Children ≥6 years and Adolescents: IV: 20 units/kg

Cinryze: Limited data available: Children ≥6 years and Adolescents: IV: 1,000 units; may repeat dose in 1 hour if needed (Lumry 2013)


Allow vial and diluent (SWFI) to come to room temperature prior to reconstitution. Reconstitute each vial with 5 mL (Cinryze 500 units), 10 mL (Berinert 500 units), 4 mL (Haegarda 2,000 units), 6 mL (Haegarda 3,000 units), or 3 mL (Berinert 1,500 units [Canadian product]) of SWFI using a double-ended transfer needle or the provided transfer set. A silicone-free syringe may be required for reconstitution (refer to manufacturer's labeling). Do not use product if there is no vacuum in the vial. After combining with diluent, gently swirl vial (do not shake) until the powder is completely dissolved. Reconstituted product should be clear and colorless or slightly blue (Cinryze only); do not use if turbid, discolored, or contains particles. The provided filter needle or transfer set should be used to withdraw the reconstituted product. Remove filter needle and attach reconstituted solution to infusion set or appropriate needle for infusion. Do not mix with other medicinal products.



Berinert (500 units): Administer intravenously at ~4 mL/minute by a separate infusion line.

Berinert (1,500 units) [Canadian product]: Administer intravenously by slow injection by a separate infusion line.

Cinryze (500 units): Administer intravenously at 1 mL/minute (as a guideline, administer 1,000 units over 10 minutes and 500 units over 5 minutes)


Haegarda (2,000 or 3,000 units): For SubQ injection only in the abdominal area or other SubQ injection sites. Rotate injection sites.

Self-administration: Following patient training and instructions on self-administration, patient may self-administer treatment (Berinert) or prophylaxis (Cinryze, Haegarda) therapy. Epinephrine should be available during self-administration in the event of an acute, severe hypersensitivity reaction. Patient suffering from an acute laryngeal hereditary angioedema (HAE) attack and self-administering should be informed to seek immediate medical attention following treatment (potential for airway obstruction to occur).

A silicone-free syringe may be required for administration (refer to manufacturer's labeling).


Berinert: Store intact vials at 2°C to 30°C (36°F to 86°F); do not freeze. Store in original carton; protect from light. Use within 8 hours of reconstitution (Canadian labeling recommends immediate use after reconstitution); do not refrigerate or freeze reconstituted solution. Discard any unused product.

Cinryze: Store intact vials at 2°C to 25°C (36°F to 77°F); do not freeze. Store in original carton; protect from light. Use within 3 hours of reconstitution; do not refrigerate or freeze reconstituted solution. Discard any unused product.

Haegarda: Store intact vials at ≤30°C (86°F); do not freeze. Store in original carton; protect from light. Use within 8 hours of reconstitution; do not refrigerate or freeze reconstituted solution. Discard any unused product.

Drug Interactions

Androgens: May enhance the thrombogenic effect of C1 inhibitors. Monitor therapy

Estrogen Derivatives: May enhance the thrombogenic effect of C1 inhibitors. Monitor therapy

Progestins: May enhance the thrombogenic effect of C1 inhibitors. Monitor therapy

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.


Central nervous system: Headache (17%)

Dermatological: Skin rash (21%)

Local: Injection site reaction (35%)

Respiratory: Nasopharyngitis (19%)

1% to 10%:

Dermatologic: Pruritus (8%)

Gastrointestinal: Nausea (≥5%), dysgeusia (5%), vomiting (8%)

Hypersensitivity: Hypersensitivity reaction (7%)

Immunologic: Antibody development (9%)

Miscellaneous: Fever (>5%)

<1%, postmarketing, and/or case reports: Anaphylaxis, arterial thromboembolism, chills, erythema at injection site, infusion site reaction, injection site pain, shock, thrombosis, venous thromboembolism


Concerns related to adverse effects:

• Hypersensitivity: Severe hypersensitivity reactions (eg, urticaria, hives, tightness of the chest, wheezing, hypotension, anaphylaxis) may occur during or after administration. Signs/symptoms of hypersensitivity reactions may be similar to the attacks associated with hereditary angioedema, therefore, consideration should be given to treatment methods. In the event of acute or severe hypersensitivity reactions, discontinue treatment immediately.

• Thrombotic events: Serious arterial and venous thromboembolic events have been reported at recommended intravenous doses and when used off-label at doses higher than recommended. Risk factors may include the presence of an indwelling venous catheter/access device, prior history of thrombosis, underlying atherosclerosis, use of oral contraceptives or certain androgens, morbid obesity, and immobility. Consider potential risk of thrombosis with use, and closely monitor patients with preexisting risks for thrombotic events.

Dosage form specific issues:

• Human plasma: Product of human plasma; may potentially contain infectious agents (eg, viruses, the variant Creutzfeldt-Jakob disease [vCJD] agent and, theoretically, the Creutzfeldt-Jakob disease [CJD] agent) that could transmit disease. Screening of donors, as well as testing and/or inactivation or removal of certain viruses, reduces the risk. Infections thought to be transmitted by this product should be reported to the manufacturer.

Other warnings/precautions:

• Self-administration: Due to the potential for airway obstruction, patients suffering from an acute laryngeal hereditary angioedema (HAE) attack and self-administering should be informed to immediately seek medical attention following treatment.

Monitoring Parameters

Signs/symptoms of hypersensitivity reactions and thrombotic events.

Pregnancy Considerations

C1 esterase inhibitor is endogenous to human plasma. Information is available following maternal administration for the prevention and treatment of hereditary angioedema (HAE) attacks, and use has not been associated with adverse pregnancy outcomes due to C1 inhibitor (human) (Baker 2013; Fox 2017; Martinez-Saguer 2010).

C1 inhibitor (human) is the preferred treatment for HAE during pregnancy and may be used for acute attacks, short-term prophylaxis, and long-term prophylaxis. Pre-procedural prophylaxis before uncomplicated natural delivery is not mandatory; however, C1 inhibitor (human) should be immediately available for on-demand use. Pre-procedural prophylaxis is recommended before labor and delivery when symptoms have been recurring frequently during the third trimester and the patient's history includes genital edema caused by mechanical trauma; during forceps delivery or vacuum extraction; before a caesarean section; before surgery or general anesthesia when intubation is required; and before interventions such as chorionic villus sampling, amniocentesis, and induced surgical abortion. Women with HAE should be monitored closely during pregnancy and for at least 72 hours after delivery (WAO/EEACI [Maurer 2018]).

Patient Education

What is this drug used for?

• It is used to treat swelling attacks in people with hereditary angioedema (HAE).

• It is used to prevent swelling attacks in people with hereditary angioedema (HAE).

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Injection site irritation

• Nose irritation

• Throat irritation

• Nausea

• Vomiting

• Bad taste in mouth

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Severe dizziness

• Passing out

• Mouth discoloration

• Fast heartbeat

• Severe headache

• Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight

• Blood clots like numbness or weakness on one side of the body; pain, redness, tenderness, warmth, or swelling in the arms or legs; change in color of an arm or leg; chest pain; shortness of breath; fast heartbeat; or coughing up blood

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

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Further information

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