Idarucizumab (Praxbind) is a humanized monoclonal antibody that is used to reverse the effects of dabigatran.

Idarucizumab (Praxbind) Uses:

• Reversal of dabigatran:

  • It is indicated to reverse the anticoagulant effects of dabigatran in patients with uncontrolled or life-threatening bleeding, and in patients undergoing an emergency procedure.

Idarucizumab (Praxbind) Dose in Adults:

Idarucizumab (Praxbind) Dose in the treatment of reversal of dabigatran:

• 5 gms administered intravenously as two separate doses of 2.5 gms each no more than 15 minutes apart.
• An additional two doses of 2.5 gms (total 5 gms) may be administered if the coagulation profile is abnormal or the patient is actively bleeding, or another surgical procedure is required.
• Patients who develop intracranial or refractory bleeding secondary to dabigatran, hemodialysis, or re-dosing may be considered if refractory bleeding occurs after the initial dose of idarucizumab.

Use in Children:

The safety and efficacy of the drug in children have not been established.

Pregnancy Risk Category: N (not defined)

• It has not yet been tested in pregnant women or animals.

Idarucizumab use during breastfeeding:

• It is unknown if the drug will be excreted into breastmilk.
• It is recommended that you use it with caution if you are breastfeeding.

Idarucizumab (Praxbind) Dose in Kidney Disease:

Adjustment in the dose is not necessary in patients with renal disease. Furthermore, the reversal effect of idarucizumab is not affected by renal dysfunction.

Idarucizumab (Praxbind) Dose in Liver disease:

In the manufacturer's labeling, adjustments in the dose has not been provided/ recommended.

Side Effects of Idarucizumab (Praxbind):

• Central nervous system:

  • Headache

• Gastrointestinal:

  • Constipation
  • Nausea

Uncommon Side effects of Idarucizumab (Praxbind):

• Hypersensitivity:

  • Hypersensitivity reaction including
    • Bronchospasm
    • Fever
    • Hyperventilation
    • Pruritus
    • Skin rash

Contraindications to Idarucizumab (Praxbind):

• Allergy reactions to idarucizumab and any component of this formulation

Warnings and precautions

• Hypersensitivity reactions

  • Not all hypersensitivity reactions have been evaluated. 
  • Patients with hypersensitivity reactions to any component of the drug or the drug should weigh the benefits and risks of therapy.
  • If a hypersensitivity reaction occurs, the treatment should be stopped immediately.

• Thromboembolic Risk:

  • Because these patients have an underlying condition that predisposes to thromboembolic episodes, the risk of them developing thromboembolic complications increases when dabigatran is stopped.
  • As soon as possible, you should resume treatment with dabigatran. After 24 hours, it can be restarted.
  • The underlying disease may not reflect the risk of thromboembolic event (DVT, Pulmonary embolisms, NSTEMI and stroke).

• Inheritary fructose intolerance

  • As an excipient, the formulation contains 4 grams of sorbitol
  • Injectable administration of fructose may cause serious reactions in patients with fructose intolerance. These reactions could include:
    • acute liver failure,
    • hypoglycemia,
    • Hypophosphatemia
    • metabolic acidosis,
    • Hyperuricemia and
    • Death
  • It is unknown what the minimum amount of sorbitol could cause these adverse reactions.

Monitoring parameters:

• Monitor for thromboembolic events, features of active bleeding, and coagulation profile (aPTT)
• The following monitoring schedule may be followed in patients with dabigatran overdose:
  • Baseline aPTT at presentation,
  • repeat aPTT at 2 hours of exposure if the exposure time is known or after the presentation if the exposure time is not known
  • Every 12 hours thereafter until the coagulation profile (aPTT) returns to normal.

How to administer Idarucizumab (Praxbind)?

It is available for intravenous administration only.

• Before administering the drug, flush the pre-existing intravenous line with 0.9% saline.
• Do not shake the solution.
• The dose may be administered as an undiluted intravenous bolus or an intravenous infusion.
• While infusing the drug, it should not be mixed or administered with other intravenous solutions in the same IV line.
• The drug should be administered immediately once it has been removed from the vial.
• The first vial should be infused over a maximum time of 5 - 10 minutes while the second infusion of 2.5 gms may be administered over a maximum period of 15 minutes (following the first 2.5 gms dose).

Mechanism of action of Idarucizumab (Praxbind):

• Idarucizumab, a humanized monoclonal antibody (Fab) that binds dabigatran (and its metabolites) is called "humanized monoclonal antibody fragment" (Fab).
• It reverses the effects of dabigatran's action by binding to it with a 350-fold greater affinity than thrombin. It quickly neutralizes its effects.

The onset of action in patients with uncontrolled bleeding:

• The effects of the drug are observed within minutes, however, it takes 11.4 hours to secure hemostasis.

Duration of action:

• Usually lasts for a minimum of 24 hours

Metabolism:

• Like other immunoglobulins, it is degraded into small peptides and amino acids.

Half-life elimination:

• 47 minutes (initial);
• 10.3 hours (terminal)

Excretion:

• About 32% of the drug is excreted within the first 6 hours in urine and <1% in the following 18 hours)

International Brands of Idarucizumab:

• Praxbind
• Prizbind

Idarucizumab Brand Names in Pakistan:

No Brands Available in Pakistan.