[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Biologics for asthma](https://durgical.com/en/pharmacology/classes/biologics-for-asthma/) › Omalizumab

# Omalizumab

## Biologics for asthma?

Biologics for asthma

An anti-IgE antibody injected under the skin for severe allergic asthma, nasal polyps, chronic hives and food allergy; it can cause anaphylaxis.

Updated Nov 1, 2026

## Quick facts

**Group**
[Biologics for asthma](https://durgical.com/en/pharmacology/classes/biologics-for-asthma/)

**Target**
Immunoglobulin E (Fc region)

**Used for**
Chronic rhinosinusitis with nasal polyps

**Key effects**
Injection-site pain · Headache · Joint and limb pain

**Monitor**
Asthma control and exacerbations

**ATC**
R03DX05

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

◆**Immunoglobulin E (Fc region)**Omalizumab

ⓘ The figure shows a single-chain fragment of omalizumab bound to the Fc region of human IgE.

**Target in 3D:** Immunoglobulin E (Fc region). PDB structure 7SHY (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/7SHY) · Drag to rotate · pinch to zoom

Omalizumab is a humanised monoclonal antibody that binds the Cε3 domain of free IgE, the same part IgE uses to attach to its high-affinity receptor (FcεRI) on mast cells and basophils. With less free IgE, fewer IgE molecules sit on these cells, and the cells reduce their FcεRI. Allergen exposure then triggers less degranulation and less release of histamine and leukotrienes. It does not bind IgE already on cells, so it does not trigger degranulation itself.

- Omalizumab captures free IgE in the blood
- IgE can no longer load onto mast-cell FcεRI
- Mast cells and basophils lower their FcεRI
- Allergens trigger less mediator release

## Indications

- Moderate to severe allergic asthma not controlled with inhaled corticosteroids [Asthma →](https://durgical.com/en/conditions/asthma/)
- Chronic rhinosinusitis with nasal polyps [Chronic rhinosinusitis and nasal polyps →](https://durgical.com/en/conditions/chronic-rhinosinusitis-and-nasal-polyps/)
- Chronic spontaneous urticaria [Urticaria and angioedema →](https://durgical.com/en/conditions/urticaria-and-angioedema/)
- Reduction of allergic reactions after accidental exposure in food allergy

## Adverse effects

### Common

- Injection-site pain, redness, swelling or bruising
- Headache, tiredness and dizziness
- Joint and limb pain
- Sore throat, runny nose

### Serious (rare, important)

- Anaphylaxis, which can occur after any dose, including late after the first ones
- Serum-sickness-like reaction: fever, rash, joint pain and swollen glands days after a dose
- Chest pain, breathlessness or stroke-like symptoms: urgent assessment

## Contraindications

- Hypersensitivity to omalizumab
- Not for an acute asthma attack
- Caution with helminth (worm) infection or high risk of it

## Key interactions

**Inhaled and oral corticosteroids**
Are not stopped suddenly when omalizumab starts; tapering is supervised

## What is monitored

- Observation after injections for anaphylaxis, longer for the first doses
- Asthma control and exacerbations
- Total IgE and weight before starting (they guide the regimen)

## Administration and safety

- Subcutaneous injection; the first doses are given in a healthcare setting with anaphylaxis treatment available
- Prefilled syringes are warmed to room temperature without heating and not shaken
- Patients allowed home injection are taught to recognise anaphylaxis and may carry epinephrine

## Pregnancy and breastfeeding

IgG antibodies cross the placenta, especially late in pregnancy; registry data have not shown a clear increase in malformations, and use is decided with the specialist.

## Nursing care

- Have epinephrine ready and observe the patient after each injection
- Teach signs of anaphylaxis: wheeze, throat tightness, faintness, hives
- Ask about worm infections and travel or living in endemic areas
- Remind that the rescue inhaler is still needed for attacks

## Pharmacokinetics

**Absorption**
Slowly absorbed after subcutaneous injection

**Elimination**
Removed with IgE–antibody complexes through the reticuloendothelial system

**Onset and duration**
Benefit builds over weeks to months

## Memory aid

OMALizumab: Only Mops up ALlergic IgE.

## Test yourself

Think of the answer, then tap the question to see it.

## What does omalizumab bind?

Free IgE, at the site IgE uses to attach to its high-affinity receptor.

## Why is the patient observed after omalizumab injections?

Anaphylaxis can occur after any dose.

## What are two indications of omalizumab besides asthma?

Chronic spontaneous urticaria and nasal polyps (also food allergy).

## Can omalizumab treat an acute asthma attack?

No; it reduces future exacerbations over weeks.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/omalizumab/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 2

- [Mepolizumab](https://durgical.com/en/pharmacology/mepolizumab/)
- [Dupilumab](https://durgical.com/en/pharmacology/dupilumab/)

## Related conditions 3

- [Asthma](https://durgical.com/en/conditions/asthma/)
- [Chronic rhinosinusitis and nasal polyps](https://durgical.com/en/conditions/chronic-rhinosinusitis-and-nasal-polyps/)
- [Urticaria and angioedema](https://durgical.com/en/conditions/urticaria-and-angioedema/)

[← Back to the class: Biologics for asthma](https://durgical.com/en/pharmacology/classes/biologics-for-asthma/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Omalizumab Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a603031.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=R03DX05) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/omalizumab/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/omalizumab/