C1 Esterase Inhibitor Recombinant (Intravenous)

In patients suffering from hereditary angioedema (HAE), the esterase inhibitor recombinant drug therapy replaces the damaged or missing C1 esterase inhibitor.


By replacing a missing or malfunctioning C1 esterase inhibitor, the esterase inhibitor recombinant drug is an immune modulator that prevents a cascade of conditions that ultimately lead to the development of hereditary angioedema. Once HAE develops in an individual, it causes increased vascular permeability, swelling, edema, and laryngospasm. Esterase inhibitor recombinant prevents the progression of these conditions by suppressing the activation of the enzyme.

Patients who have hereditary angioedema will have low levels of the C1 esterase inhibitor, which can be discovered through testing. Early indications of HAE include swelling of the face, throat, hands, feet, stomach, bowels, or sexual organs.

Conditions treated

  • Hereditary angioedema

Type of medicine

  • Replacement enzyme inhibitor

Side Effects

Here is a list of the most common side effects experienced by patients, while receiving esterase inhibitor recombinant drug treatments. This is not a complete list of every possible side effect, however. Any adverse reactions to taking this drug therapy should be reported to the patient's doctor as soon as possible. Side effects experienced at a high rate of frequency or severity should be treated as an adverse reaction to the drug and the patient should consult his or her doctor immediately. A reduction in dosage or an alternative drug therapy may be necessary.

The side effects most commonly observed in patients taking esterase inhibitor recombinant include:

  • Chest pain
  • Head congestion
  • Hoarse voice or other vocal changes
  • Nausea and/or vomiting
  • Tenderness or pain in the face, usually near the eyes or in the cheeks
  • Rash
  • Sore throat
  • Tightness in the chest, sometimes accompanied by trouble breathing

There are some side effects that are less common or those which have been reported with unknown rates of frequency. While these reactions to esterase inhibitor recombinant drug therapy may be rare and/or uncommon, the patient should be aware of the possibility of developing one or more of these side effects. They may occur mildly, not requiring medical treatment, but, in cases where these side effects create a discomfort for the patient, he or she should report the incidences to the prescribing physician. There may be ways to reduce or eliminate these side effects.

  • Redness or flushing of the skin
  • Itching
  • Unusually warm skin
  • Confusion
  • Difficulty breathing or swallowing
  • Dizziness or lightheadedness
  • Double vision
  • Rapid heartbeat
  • Unexplained tiredness or body weakness
  • Hives
  • Difficulty moving limbs or making facial expressions
  • Tingling or a feeling of numbness in the limbs or the face
  • Pain in the arms and legs, accompanied by redness or swelling
  • Puffing and/or swelling of the eyelids or around the eyes, tongue, or lips
  • Speech problems
  • Coordination problems, especially in walking, speaking, or organizing thoughts

Below are other uncommon side effects reported by patients undergoing esterase inhibitor recombinant drug therapy:

  • Diarrhea
  • Headaches
  • Stomach or abdominal pain
  • General body pain
  • Skin inflammations, including burning, blistering, discoloration, hives, and infection
  • Change in taste, which may include a loss of taste
  • Fever
  • Muscle aches
  • Pain at the catheter site
  • Congested or runny nose

The most common respiratory side effects associated with esterase inhibitor recombinant are bronchitis and sinusitis. Also experienced by some patients have been upper respiratory tract infections and viral upper respiratory tract infections. Adverse reactions associated with the nervous system are rare, but headaches are the most common conditions reported in this respect. The musculoskeletal system has also been affected by the treatment with patients most commonly reporting incidences of limb injury, back pain, and general muscle pain.

In addition to previously mentioned dermatological side effects, patients have also developed pruritus, which is identified by a state of severe itching. Some of the most common cardiovascular conditions instigated by esterase inhibitor recombinant have been myocardial infarctions, deep vein thrombosis, and transient ischemic attacks. As is the case with any severe reactions to treatment, the patient should seek medical assistance immediately, where these conditions develop. It may be necessary to alter or stop treatment, if these side effects are severe enough or occur frequently.


In treating an adult for hereditary angioedema, the patient should receive 1,000 units of esterase inhibitor recombinant via IV infusion, delivered at a rate of 1 mL per minute (1,000 units/ 10 mL). This treatment should be repeated every three to four days.

Esterase inhibitor recombinant can be used to directly treat the symptoms of an angioedema attack by delivering a dose of 20 units per kilogram of the patient's body weight. Again, this is delivered via an intravenous route at a rate of 4 mL per minute (500 units/10 mL).

In treating children 13 years of age or older, esterase inhibitor recombinant can also be administered as an effective treatment. Here, also, the patient should receive 20 units per kilogram of body weight. The IV infusion should be delivered at the same rate of mL per minute (500 units/10 mL).

Major Drug Interactions

Adverse drug interactions pose another problem in seeking treatment for any medical condition. When one medication or drug interacts negatively with another, it can make one treatment or the other ineffective. In a worst case scenario, the combination of drugs can induce a severe reaction for the patient, which may become life-threatening without treatment. This is why any doctor will inquire about the patient's history of medications and drug use. While it may feel embarrassing or raise other concerns for the patient, it's important to be open and forthright about present and past drug use. The patient should be reminded that this information is confidential to encourage an honest divulgence of drug use.

While it is important to share a history of prescription drugs, the patient should also share their history of nonprescription substances. This, of course, includes over the counter medications, but any vitamins, herbal remedies, or other supplements should also be shared. Also as important is a discussion about alcohol and recreational drug use, as these substances can also cause an adverse reaction when interacting with the esterase inhibitor recombinant treatment.

Here are the drugs most commonly known to adversely interact with esterase inhibitor recombinant. Prior to beginning the new enzyme inhibitor therapy, the patient should be advised to reveal if they taken any of the following medications with the prescribing physician:

  • Carfilzomib
  • Kyprolis
  • Lenalidomide
  • Pomalidomide
  • Pomalyst
  • Revlimid
  • Thalidomide
  • Thalomid

Patients should not make changes to the dosages of current medications, nor should they start or stop medications, without first consulting their doctor. Any change to the individual's body chemistry can cause unexpected reactions. By changing medications unexpectedly, the patient may suffer adverse reactions or such changes can result in making one or more medications ineffective. Changes can be safely guided by the patient's doctor to ensure achieving the desired affect without compromising other treatments.


Another important aspect in taking the patient's history is discussing past and current medical conditions. Pre-existing health problems can be exasperated by administering the esterase inhibitor recombinant treatment, where the doctor hasn't been fully informed. Proper disclosure will give the physician the necessary knowledge to take cautionary steps or to recommend alternate treatments.

Allergies should also be disclosed to the doctor, as some allergic reactions may be instigated by administering esterase inhibitor recombinant drug treatments.

Specifically, illnesses and conditions known to affect how esterase inhibitor recombinant treatment can interact with the patient are listed below.

  • Hypersensitivity
  • Thromboembolic Events
  • Atherosclerosis
  • Use of oral contraceptives

The Food and Drug Administration has classified esterase inhibitor recombinant as a class B pregnancy drug. In studies conducted on rats and rabbits, doses 12.5 times greater than the normal human dosage of 50 IU/kg was administered, but results could not definitively identify an effect on embryofetal development. Even so, animal testing is not always predictive of a drug's effect on human patients. Therefore, esterase inhibitor recombinant should only be administered to pregnant women where the treatment's benefits will greatly outweigh the risks. Studies on pregnant women are insufficient to provide reliable data.

Similarly, the effect of esterase inhibitor recombinant, when administered near term or while the patient is in labor, has not been established. The enzyme inhibitor should only be administered to pregnant women when necessary.

Studies on breastfeeding are also inconclusive. As it's unknown if the esterase inhibitor recombinant drug is secreted into breast milk, pregnant women are advised to breastfeed with caution, while under treatment.

In treating adolescents, a study of 17 patients was conducted. The test group, aged 13-17 years, was treated for 52 hereditary angioedema attacks. Of that group, eight patients, or 47%, experienced adverse side effects from the treatment. No serious reactions were reported, however. The most common side effects experienced in the test group were headaches, abdominal pain, and oropharyngeal pain.


Esterase inhibitor recombinant should be kept in its original packaging and stored in a place away from direct light. When stored at 2°C to 25°C (36°F to 77°F), the drug has a shelf life of 48 months. Do not freeze.

Like all medications, esterase inhibitor recombinant should be stored in a place out of the reach of children and pets. In some cases, children may be able to open safety caps, so even these types of containers should be kept out of their reach to avoid accidental poisoning.

Typically, esterase inhibitor recombinant will be administered in hospital setting by a trained caregiver, but at-home treatments may be authorized. In those cases, the patient should be instructed in the proper storage, use, and disposal of the drug. Additionally, the prescribing physician should ensure that the patient has adequate equipment and facilities for storing the drug and administering treatments.


Esterase inhibitor recombinant drug therapy can be beneficial in treating hereditary angioedema and the symptoms of that condition, provided the patient and doctor communicate fully about drug and medical histories. Additionally, patients with a known allergy to rabbits or products derived from rabbits should not receive this treatment, as it may result in anaphylaxis. For similar reasons, patients known to experience a state of hypersensitivity from other C1 esterase inhibitor products should not be treated with the esterase inhibitor recombinant drug. Additionally, children under 13 years of age should not be treated with C1 esterase inhibitor products.

Overall, esterase inhibitor recombinant treatments should only be given where the benefits outweigh the risks of adverse reactions in the treatment of hereditary angioedema and its symptoms. The relief from this condition can help the patient and risking some side effects may be worth it for the possible alleviation of the condition. When side effects do arise, the patient's doctor may be able to prescribe other medications to alleviate or reduce those adverse reactions. Likewise, temporary changes in diet or physical activity can help to manage symptoms. Patients are advised to also discuss this possibility with their doctors. By communicating and working together, the patient and doctor can ensure receiving the best possible benefits from administering the esterase inhibitor recombinant drug therapy.

Last Reviewed:
December 24, 2017
Last Updated:
April 04, 2018
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