Andexanet alfa: administration quick reference guide (Guidelines)
TAM (Treatments and Medicines) NHS Highland
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.