The Evusheld carton contains co-packaged tixagevimab 150mg/1.5mL solution for injection (single-dose vial; dark grey cap) and cilgavimab 150mg/1.5mL solution for injection (single-dose vial; white cap); the vials do not require reconstitution. Evusheld storage instructions are: store at 2° to 8°C (refrigerate, do not freeze), do not shake, protect from light.1
The solutions for injection contain no preservative; therefore, prepared syringes should be administered immediately. If this is not possible, and the prepared tixagevimab and cilgavimab syringes need to be stored, they can be done so either in a refrigerator at 2°C to 8°C or at room temperature up to 25°C. Note, the total time from vial puncture to administration should not exceed four hours.1
Ensure the name and the batch number of the administered product is recorded in the patient’s medical record, to improve traceability if needed.
A full description of handling and administration procedures for Evusheld is provided within the Medsafe data sheet, product registration information, and consumer medicine information, and in the New Zealand Formulary and the Therapeutics TAG update “Use of Evusheld for the prevention and treatment of COVID-19”.1,4,8,16,18 Note that some of the information may refer to the approved dose rather than the newly recommended dose.
The current New Zealand recommendation for a 600mg dose of Evusheld (tixagevimab 300mg and cilgavimab 300mg) requires the following adaptation:4
- two cartons of Evusheld (2 x 150mg of each antibody) need to be used
- two 150mg vials of tixagevimab should be drawn up into one syringe (ideally labelled)
- two 150mg vials of cilgavimab should be drawn up into a second syringe (ideally labelled)
- tixagevimab 300mg should be delivered intramuscularly to one gluteal muscle
- cilgavimab 300mg should be delivered intramuscularly to the contralateral gluteal muscle.
The practitioner administering Evusheld should be appropriately skilled in giving gluteal intramuscular injections. The healthcare clinic should also be equipped and staffed to handle the possibility of allergic adverse reactions.
It should be noted, there are two sites for gluteal injection (dorsogluteal and ventrogluteal), and a guide to correct technique, needle positioning and patient factors can be found in a review of success factors in the psychiatric setting.20 Historically, choice of site has been based upon practitioner preference and confidence rather than evidence, and many would give the intramuscular injection in the dorsogluteal area located in the “upper outer quadrant” of the gluteal muscle. However, evidence-based literature favours the ventrogluteal area, with regard to safety, as the dorsogluteal area is close to the sciatic nerve and gluteal artery.20
A refresher of good practice for intramuscular injection technique in general is available in an online continuing educational activity that summarises the anatomic landmarks, safety precautionary checklists, the recommended procedural steps and the complications to be aware of.21 Similar information for intramuscular injection into the dorsogluteal site is outlined in the Canterbury region “Fluid and Medication Management” manual.22
Adverse events to Evusheld should be reported in the normal manner with CARM.