Administering antibody cocktail therapy

Monoclonal antibody cocktail therapy has become a game-changer and given promising and encouraging results against moderately infected COVID-19 patients not requiring oxygen with comorbidities.

The antibody cocktail therapy is considered to be a new option and evolving treatment to successfully tackle patients infected with COVID-19 and at the same time suffering from comorbidities like age more than 60 years, COPD, bronchial asthma, chronic kidney disease, diabetes, liver disease, patients on chemotherapy, ischemic heart disease. This therapy is given in a combination of Casirivimab and Imdevimab, which are laboratory-made monoclonal antibodies, and tend to work just like antibodies present in the human body in response to any viral infection. These two separate drugs are mixed like a cocktail. Then the concoction is administered to the patient in 250 ml of normal saline which should be infused over 30-60 minutes. This therapy is safe and efficacious when it comes to the widest spread variants.

How to administer antibody cocktail therapy?

Intravenous infusion protocol

• 600 mg of casirivimab and 600 mg of imdevimab should be administered together as a single intravenous infusion by qualified paramedical staff.
• Remove the casirivimab and imdevimab vials from refrigerated storage and allow to equilibrate to room temperature for approximately 20 minutes before preparation. Do not expose to direct heat. Do not shake the vials.
• Obtain an IV infusion bag containing 250 mL of 0.9 per cent NS Injection.
• Withdraw 5 mL of casirivimab and 5 mL of imdevimab from each respective vial using two separate syringes and dilute together in the infusion bag containing 0.9 per cent NS.
• Gently invert infusion bag by hand approximately 10 times. Do not shake.
• The infusion to be administered IMMEDIATELY (as it is preservative-free) over 30- 60 min.
• Patients should be monitored for atleast 1 hour after the infusion.
• Store the remaining casirivimab and imdevimab vials in the refrigerator between 2°C to 8°C. It should be administered to second patient within 48 hours.

Subcutaneous injection protocol

• Remove the casirivimab and imdevimab vials from refrigerated storage and allow them to equilibrate to room temperature for approximately 20 minutes before preparation. Do not expose to direct heat. Do not shake the vials.
• Prepare two syringes each of 2.5 ml of Casrivimab   
• Prepare two syringes each of 2.5 ml of Imdevimab
• These four syringes each of 2.5 ml are to be administered subcutaneously at different injection sites into the thigh or abdomen except for 2 inches (5 cm) around the navel. The waistline should be avoided.
• Patients should be observed for at least 15 to 30 minutes after the injections.
• Store the remaining casirivimab and imdevimab vials in the refrigerator between 2°C to 8°C. It should be administered to the second patient within 48 hours.

---Dr Sunil Bhaisare, Associate Professor, General Medicine, Grant Government Medical College & Nodal Officer Dedicated Covid Critical Care Hospital, ST George's Hospital, Mumbai