Usage
Casirivimab + Imdevimab is prescribed for the treatment and post-exposure prophylaxis of mild to moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing at least 40 kg) who are at high risk for progression to severe COVID-19, including hospitalization or death. It is not authorized for use in patients hospitalized due to COVID-19, requiring oxygen therapy due to COVID-19, or who require an increased oxygen flow rate due to COVID-19 on top of underlying non-COVID-19 related comorbidities.
Pharmacological Classification: Monoclonal antibody combination.
Mechanism of Action: Casirivimab and Imdevimab are neutralizing monoclonal antibodies that bind to non-overlapping epitopes on the spike protein of SARS-CoV-2, blocking the virus’s ability to attach to and enter human cells.
Alternate Names
Casirivimab and Imdevimab; REGN-COV2; Ronapreve.
How It Works
Pharmacodynamics: Casirivimab and Imdevimab neutralize SARS-CoV-2 by binding to the receptor-binding domain of the spike protein, preventing viral entry into host cells. This reduces viral replication and the subsequent inflammatory response.
Pharmacokinetics: Administered intravenously or subcutaneously, both antibodies exhibit similar pharmacokinetic profiles. The volume of distribution is relatively small, suggesting limited tissue penetration. Metabolism of monoclonal antibodies typically occurs through general protein catabolism pathways, and renal excretion is minimal. Elimination is primarily mediated through intracellular catabolism.
Mode of Action: Receptor binding to the spike protein.
Elimination Pathways: Primarily via intracellular catabolism.
Dosage
Standard Dosage
Adults: 600 mg of casirivimab and 600 mg of imdevimab administered together as a single IV infusion over at least 30-60 minutes (via pump or gravity) or by subcutaneous injection. For ongoing prophylaxis (for individuals at risk of ongoing SARS-CoV-2 exposure and unlikely to respond to vaccination), an initial loading dose of 600 mg of each antibody is followed by 300 mg of each every 4 weeks.
Children (12 years and older weighing at least 40 kg): Same as adult dosing.
Special Cases:
- Elderly Patients: No dosage adjustment is required.
- Patients with Renal Impairment: No dosage adjustment is required.
- Patients with Hepatic Dysfunction: No dosage adjustment is required in mild to moderate impairment, but data is limited. Not studied in severe hepatic impairment.
- Patients with Comorbid Conditions: Dosage adjustments are not explicitly defined for specific comorbid conditions, but individual patient factors should be considered.
Clinical Use Cases
Casirivimab + Imdevimab is not indicated for use in clinical settings requiring intubation, surgical procedures, mechanical ventilation, or intensive care unit (ICU) use related to COVID-19. It is authorized only for non-hospitalized patients or pre-exposure prophylaxis. It is not for emergency situations like cardiac arrest.
Dosage Adjustments
No specific dosage adjustments are needed for renal or hepatic impairment, metabolic disorders, or genetic polymorphisms. However, careful clinical monitoring is advised.
Side Effects
Common Side Effects
Injection site reactions (pain, swelling, erythema), chills, nausea, dizziness, pruritus.
Rare but Serious Side Effects
Hypersensitivity reactions (including anaphylaxis), severe infusion-related reactions.
Long-Term Effects
Data on long-term effects are limited.
Adverse Drug Reactions (ADR)
Anaphylaxis, severe infusion-related reactions requiring immediate medical attention.
Contraindications
Known hypersensitivity to casirivimab, imdevimab, or any of the excipients. Age under 12 years or weight less than 40 kg. Patients hospitalized due to COVID-19, requiring oxygen therapy due to COVID-19, or having increased oxygen requirements due to COVID-19 on top of underlying non-COVID-19 related comorbidities.
Drug Interactions
No formal drug interaction studies have been performed. As monoclonal antibodies are not metabolized by CYP450 enzymes, interactions with drugs metabolized by this pathway are unlikely. However, it is possible that Casirivimab + Imdevimab may interfere with the immune response to COVID-19 vaccines.
Interactions with commonly prescribed medications, OTC drugs, supplements, food, and lifestyle factors are not well-characterized.
Pregnancy and Breastfeeding
Limited data are available. Use only if the potential benefit outweighs the potential risk to the fetus or neonate.
Drug Profile Summary
- Mechanism of Action: Neutralizing monoclonal antibodies targeting the SARS-CoV-2 spike protein.
- Side Effects: Injection site reactions, chills, nausea, dizziness, pruritus, hypersensitivity reactions, infusion-related reactions.
- Contraindications: Hypersensitivity, age <12 years or weight <40 kg, hospitalized COVID-19 patients, those requiring oxygen therapy due to COVID-19, or those with increased oxygen requirements due to COVID-19 on top of underlying non-COVID-19 related comorbidities.
- Drug Interactions: Limited data; potential interference with COVID-19 vaccines.
- Pregnancy & Breastfeeding: Limited data; use with caution.
- Dosage: 600 mg casirivimab + 600 mg imdevimab IV or SC, single dose; repeat dosing at lower dose for prophylaxis.
- Monitoring Parameters: Monitor for infusion-related and hypersensitivity reactions during and after administration (at least 1 hour post-infusion). Monitor vital signs.
Popular Combinations
Not applicable. Casirivimab and imdevimab are intended for use in combination only and are not generally combined with other drugs for COVID-19 treatment.
Precautions
Pre-screening for allergies, assess for contraindications. Cautious use in pregnancy and breastfeeding. Monitor pediatric and elderly patients closely.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Casirivimab + Imdevimab?
A: 600 mg of casirivimab and 600 mg of imdevimab administered as a single IV infusion over at least 30-60 minutes or subcutaneously.
Q2: Can Casirivimab + Imdevimab be used in hospitalized patients?
A: No, it is not authorized for hospitalized patients or those requiring oxygen due to COVID-19.
Q3: What are the common side effects?
A: Injection site reactions, chills, nausea, dizziness, pruritus.
Q4: Are there any serious side effects?
A: Yes, hypersensitivity reactions (including anaphylaxis) and severe infusion-related reactions can occur.
Q5: How does this medication work?
A: The monoclonal antibodies bind to the spike protein of SARS-CoV-2, preventing viral entry into cells.
Q6: Can it be given to children?
A: Yes, for children 12 years and older weighing at least 40 kg, the dosage is the same as for adults.
Q7: What if a dose is missed during ongoing prophylaxis?
A: Administer the missed dose as soon as possible, and adjust the subsequent dosing schedule to maintain appropriate intervals.
Q8: Can it be used to prevent COVID-19?
A: Yes, it can be used as post-exposure prophylaxis in high-risk individuals.
Q9: Is it effective against all SARS-CoV-2 variants?
A: Early research suggested efficacy against some variants, but newer variants may display resistance. It’s essential to refer to the most up-to-date information on variant-specific effectiveness. This information may vary over time as new research emerges.
Q10: Does this treatment replace vaccination?
A: No, it’s not a substitute for vaccination. Vaccination remains the primary recommended method for preventing COVID-19.
