Regen-Cov Side Effects Center

Last updated on RxList: 4/26/2022
Regen-Cov Side Effects Center

What Is Regen-Cov?

Regen-Cov (casirivimab and imdevimab) is a combination of antibodies used to treat mild to moderate coronavirus disease 2019 (COVID-19) in adults and pediatric patients (12 years of age and older weighing at least 40 kg) with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progression to severe COVID-19, including hospitalization or death.

Regen-Cov is has received an Emergency Use Authorization (EUA) to permit the emergency use of the unapproved product from the U.S. Food and Drug Administration (FDA).

What Are Side Effects of Regen-Cov?

Side effects of Regen-Cov include:

  • infusion-related reactions (hives, itching, flushing, fever, shortness of breath, chest tightness, nausea, vomiting, rash) and
  • severe allergic reactions (anaphylaxis).

Dosage for Regen-Cov

The dose of Regen-Cov is 600 mg of casirivimab and 600 mg of imdevimab administered together as a single intravenous infusion or using the co-formulated vial or the individual vials by subcutaneous injection.

Regen-Cov In Children

Regen-Cov is not authorized for use in pediatric patients under 12 years of age or weighing less than 40 kg.

What Drugs, Substances, or Supplements Interact with Regen-Cov?
Regen-Cov may interact with other medicines.

Tell your doctor all medications and supplements you use.

Regen-Cov During Pregnancy and Breastfeeding

Tell your doctor if you are pregnant or plan to become pregnant before using Regen-Cov; it is unknown how it may affect a fetus. Consult your doctor before breastfeeding. Breastfeeding women with COVID-19 should follow practices according to clinical guidelines to avoid exposing the infant to COVID-19.

Additional Information

Our Regen-Cov (casirivimab and imdevimab) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

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.

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.

Regen-Cov Professional Information


ADVERSE REACTIONS And Medication Errors Reporting Requirements And Instructions

Clinical trials evaluating the safety of REGEN-COV (casirivimab and imdevimab) are ongoing [see Overall Safety Summary ].

Completion of an FDA MedWatch Form to report all medication errors and serious adverse events* occurring during REGEN-COV use and considered to be potentially related to REGEN-COV is mandatory and must be done by the prescribing healthcare provider and/or the provider's designee. These adverse events must be reported within 7 calendar days from the onset of the event:

*Serious Adverse Events are defined as:

  • death;
  • a life-threatening adverse event;
  • inpatient hospitalization or prolongation of existing hospitalization;
  • a persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions;
  • a congenital anomaly/birth defect;
  • a medical or surgical intervention to prevent death, a life-threatening event, hospitalization, disability, or congenital anomaly.

If a serious and unexpected adverse event occurs and appears to be associated with the use of REGEN-COV, the prescribing health care provider and/or the provider's designee should complete and submit a MedWatch form to FDA using one of the following methods:

  • Complete and submit the report online:, or
  • Complete and submit a postage-paid FDA Form 3500 ( and return by:
    • Mail to MedWatch, 5600 Fishers Lane, Rockville, MD 20852-9787, or
    • Fax (1-800-FDA-0178), or
  • Call 1-800-FDA-1088 to request a reporting form

IMPORTANT: When reporting adverse events or medication errors to MedWatch, please complete the entire form with detailed information. It is important that the information reported to FDA be as detailed and complete as possible. Information to include:

  • Patient demographics (e.g., patient initials, date of birth)
  • Pertinent medical history
  • Pertinent details regarding admission and course of illness
  • Concomitant medications
  • Timing of adverse event(s) in relationship to administration of REGEN-COV
  • Pertinent laboratory and virology information
  • Outcome of the event and any additional follow-up information if it is available at the time of the MedWatch report. Subsequent reporting of follow-up information should be completed if additional details become available.

The following steps are highlighted to provide the necessary information for safety tracking:

  1. In section A, box 1, provide the patient's initials in the Patient Identifier
  2. In section A, box 2, provide the patient's date of birth or age
  3. In section B, box 5, description of the event:
    1. Write “REGEN-COV use for COVID-19 under Emergency Use Authorization (EUA)” as the first line
    2. Provide a detailed report of medication error and/or adverse event. It is important to provide detailed information regarding the patient and adverse event/medication error for ongoing safety evaluation of this unapproved drug. Please see information to include listed above.
  4. In section G, box 1, name and address:
    1. Provide the name and contact information of the prescribing health care provider or institutional designee who is responsible for the report
    2. Provide the address of the treating institution (NOT the health care provider's office address).

Other Reporting Requirements

Healthcare facilities and providers must report therapeutics information and utilization data through HHS Protect, Teletracking or National Healthcare Safety Network (NHSN) as directed by the U.S. Department of Health and Human Services.

In addition, please provide a copy of all FDA MedWatch forms to:

Regeneron Pharmaceuticals, Inc

Fax: 1-888-876-2736

E-mail: [email protected]

Or call Regeneron Pharmaceuticals at 1-844-734-6643 to report adverse events.


REGEN-COV consists of 2 monoclonal antibodies (mAbs), casirivimab and imdevimab, which are not renally excreted or metabolized by cytochrome P450 enzymes; therefore, interactions with concomitant medications that are renally excreted or that are substrates, inducers, or inhibitors of cytochrome P450 enzymes are unlikely.

Read the entire FDA prescribing information for Regen-Cov (Casirivimab and Imdevimab Injection)

© Regen-Cov Patient Information is supplied by Cerner Multum, Inc. and Regen-Cov Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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