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Andexanet alfa: administration quick reference guide (Guidelines)


Andexanet alfa must only be administered on the advice of a Consultant Haematologist.

It is used to reverse the effects of rivaroxaban or apixaban in life-threatening or uncontrolled bleeding.

Patients should receive either a LOW DOSE or HIGH DOSE regimen depending on the time/dose of their last oral anticoagulant. Both are given as an initial loading dose (15 to 30 minutes) followed by a 2 hour infusion. See full administration guide for further details.
Low dose regimen = 400mg loading dose followed by 480mg over 2 hours.
High dose regimen = 800mg loading dose followed by 960mg over 2 hours.

Anticoagulant Last Dose Timing of last dose before andexanet alfa administration
less than 8 hours or unknown 8 or more hours
Rivaroxaban ≤ 10mg LOW DOSE LOW DOSE
> 10mg or unknown HIGH DOSE
Apixaban ≤ 5mg LOW DOSE LOW DOSE
> 5mg or unknown HIGH DOSE

The volume, doses and rates required for each regimen is detailed below. Andexanet alfa comes as a 200mg/20mL vial (pack size of 4 vials). Dedicated syringe pumps with the loading and maintenance rates pre-programmed are available in each location andexanet is stocked, but as an additional safety measure these should be checked against the table below.

  Low dose regimen High dose regimen
  Loading dose Maintenance infusion Loading dose Maintenance infusion
Dose and millimetres required 400mg in 40mL 480mg in 48mL 800mg in 80mL 960mg in 96mL
Vials required 2 3 (discard remainder of vial 3) 4 5 (discard remainder of vial 5)
50mL syringes required One One Two = 40mL per syringe Two = 48mL per syringe
Rate of administration via syringe pump 160mL/hr (bolus dose over 15 minutes) 24mL/hr (over 2 hours) 160mL/hour (over 30 minutes; each syringe will run for 15 minutes each) 48mL/hr (over 2 hours; each syringe will run for 60 minutes each)

Once andexanet alfa has been administered please complete this form as soon as possible. 

Last reviewed: 30/06/2021

Next review date: 30/06/2024

Approved By: TAM Subgroup of ADTC

Reviewer name(s): Pharmacist.

Document Id: TAM479