Mepolizumab
Mepolizumab is a monoclonal antibody that targets interleukin-5 (IL-5), a key protein involved in eosinophil development and inflammation. By blocking IL-5, it reduces eosinophil levels in the blood and tissues, helping to control severe eosinophilic conditions. It is prescribed for patients with severe eosinophilic asthma, eosinophilic granulomatosis with polyangiitis (EGPA), and hypereosinophilic syndrome (HES).
Mepolizumab is an IL-5 inhibitor monoclonal antibody used to treat severe eosinophilic conditions by reducing eosinophil levels.
Key facts at a glance
- ATC
- R03DX09
- RxNorm
- 1720597
- Generic
- Mepolizumab
- Class
- atc-r03
- Brands
- Nucala
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- prefilled syringe, injection
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 100mg
- Maximum
- consult physician
- Frequency
- every 4 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 300mg
- Maximum
- consult physician
- Frequency
- every 4 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 300mg
- Maximum
- consult physician
- Frequency
- every 4 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
11 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits significantly outweigh risks
regular prenatal care and fetal monitoring
Use with caution and monitor for adverse effects.
pregnancy
second trimesteravoid if possible
consider risks and benefits; may continue if already receiving therapy for severe disease
routine fetal ultrasound and monitoring
Use with caution and monitor for adverse effects.
pregnancy
third trimesteravoid if possible
avoid use near delivery if possible; discuss with healthcare provider
fetal growth monitoring and kick counts
Use with caution and monitor for adverse effects.
lactation
n/ano adjustment needed
use with caution; monitor infant for infections
observe infant for any signs of infection or immune effects
Use with caution and monitor for adverse effects.
geriatric
over 65 yearsno adjustment needed
use standard dosing; monitor for infections
routine monitoring for infections and efficacy
pediatric_age
6 to 11 yearsweight-based dosing 40mg every 4 weeks
approved for severe eosinophilic asthma; subcutaneous injection
monitor asthma control and potential infections
pediatric_age
12 to 17 years100mg every 4 weeks (adult dose)
approved for severe eosinophilic asthma and EGPA
monitor for infections and asthma exacerbations
renal_impairment
mild to moderateno adjustment needed
no dose adjustment required; monitor renal function
routine renal function monitoring
renal_impairment
severeno specific guidance
use with caution; limited data in severe impairment
monitor renal function and for infections
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderateno adjustment needed
no dose adjustment required
routine liver function monitoring
hepatic_impairment
severeno specific guidance
use with caution; limited data in severe impairment
monitor liver function and for infections
Use with caution and monitor for adverse effects.
Statistics and clinical data
Drug class
Biological drug classification
FDA approval year
Initial FDA approval for severe eosinophilic asthma
Common uses
Approved therapeutic indications
Mechanism of action
Pharmacological mechanism of action
Severe eosinophilic asthma (as add-on maintenance therapy), eosinophilic granulomatosis with polyangiitis (EGPA), and hypereosinophilic syndrome (HES) in adult patients with appropriate disease characteristics.
Mepolizumab is a monoclonal antibody (IgG1 kappa) that binds specifically to interleukin-5 (IL-5), preventing IL-5 from interacting with its receptor on eosinophil cells. Since IL-5 is the primary cytokine driving eosinophil growth, differentiation, recruitment, activation, and survival, blocking it reduces eosinophil numbers and associated inflammation.
Administered as a subcutaneous injection (typically every 4 weeks). Not for acute bronchospasm or status asthmaticus. Potential side effects include headache, injection site reactions, and increased risk of parasitic infections. Should be used with caution in patients with pre-existing helminth infections.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy