Casirivimab

Generic name: casirivimab [ KAS-i-RIV-i-mab ]
Dosage form: injectable solution (1332 mg/11.1 mL; 300 mg/2.5 mL)

What is casirivimab?

Due to the high frequency of the Omicron BA.2 sub-variant, this drug is not currently authorized in any US region; therefore, this drug may not be administered for treatment of COVID-19 under the EUA until further notice by the US FDA.

Casirivimab is an experimental medicine being studied for use in treating conditions caused by coronavirus. It is not yet known if casirivimab is safe and effective.

Casirivimab and imdevimab are also for use in people who have been exposed to COVID-19 and:

are not fully vaccinated against COVID-19; or
are vaccinated but may not have built up enough immunity (because they have certain diseases or use certain medicines), and have been or may be exposed to people who are infected with COVID-19.

Casirivimab and imdevimab are for use in adults and children at least 12 years old who weigh at least 88 pounds (40 kilograms).

The risk of COVID-19 symptoms becoming severe may be higher in people who:

are overweight;
have chronic kidney disease;
have diabetes;
have a weak immune system (caused by disease or by using certain medicine);
have sickle cell disease;
have a heart problem or high blood pressure;
have a neurodevelopmental disorder such as cerebral palsy;
have asthma or other chronic breathing disorder; or
have a tracheostomy, gastrostomy, or positive pressure ventilation (not related to COVID-19).

There also may be a higher risk of severe COVID-19 symptoms in pregnant women and in adults who are 65 and older.

Casirivimab and imdevimab are mixed together into a single solution called Regen-Cov.

Casirivimab and imdevimab are not approved to treat or prevent coronavirus or COVID-19. However, these medicines may help prevent the need for emergency medical care or admission to a hospital because of COVID-19. Regen-Cov is not authorized for use in people who are already in the hospital or receiving supplemental oxygen for COVID-19.

Casirivimab may also be used for purposes not listed in this medication guide.

Casirivimab side effects

Get emergency medical help if you have signs of an allergic reaction: hives, itching; difficult breathing; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your medical caregivers right away if you have:

throat irritation, swelling in your face or throat;
dizziness, a light-headed feeling (like you might pass out);
chest pain, wheezing, shortness of breath;
fever, chills, sweating, nausea, flushing (sudden warmth, redness, or tingly feeling);
fast or slow heartbeats, headache, pounding in your neck or ears;
weakness, tiredness;
rash, itching; or
muscle pain.

Call your doctor if you have new or worsening symptoms after the infusion, such as fever, confusion, weakness, tiredness, trouble breathing, or fast or slow heartbeats.

Less serious side effects may also occur, or you may have none at all. Not all possible side effects are known.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

Before taking this medicine

Tell your doctor if you have ever had:

a COVID-19 vaccine;
a severe allergic reaction to a COVID-19 vaccine;
any serious or chronic illness;
any allergies; or
if you are pregnant or breastfeeding.

COVID-19 is more likely to cause serious illness or death in a pregnant woman. Not all risks are known yet, but being treated with casirivimab and imdevimab is likely to be less harmful than being infected with COVID-19 during pregnancy.

How is casirivimab given?

Casirivimab and imdevimab (Regen-Cov) must be given as a combination. Casirivimab should not be used alone.

Regen-Cov is injected under the skin or into a vein by a healthcare provider.

When injected into a vein, Regen-Cov is given slowly over 20 to 50 minutes or longer. When injected under the skin, Regen-Cov is given as 2 to 4 separate injections into different areas of your body.

You will be watched for a short time after injection, to make sure you do not have an allergic reaction.

Regen-Cov is usually given as only one dose as soon as possible after you are exposed to or test positive for COVID-19, or within 10 days after the start of symptoms. You may need additional monthly doses if you continue to be exposed to COVID-19.

Being treated with Regen-Cov will not make you less contagious to other people. Keep using infection control methods such as self-isolation, social distancing, hand-washing, using protective face covering, disinfecting surfaces you touch a lot, and not sharing personal items with others.

Regen-Cov also may not keep you from becoming infected with coronavirus again. Being treated with this drug combination could also affect your body's immune response to a coronavirus vaccine. Casirivimab and imdevimab are still being studied and all of their risks are not yet known.

What happens if I miss a dose?

Call your doctor for instructions if you are on a monthly dose schedule and you miss an appointment for your injection.

What happens if I overdose?

In a medical setting an overdose would be treated quickly.

What should I avoid after receiving casirivimab?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect casirivimab?

Other drugs may affect casirivimab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer