Omalizumab: uses, side effects & brands

Written & medically reviewed by Dr. Sanjay Anbu, MBBS · Last reviewed 5 November 2026

Omalizumab treats severe allergic asthma and chronic hives. It belongs to the Biologic / immunomodulator group. These targeted injectable medicines treat severe autoimmune and allergic diseases by blocking specific immune signals.

Ask MedDroid about omalizumab →

Drug type — dosing is set by your doctor

Measure	Range
Drug class	Biologic / immunomodulator
Type	Prescription
Dose	Individual — ask your doctor or pharmacist

What it is used for

Severe allergic asthma not controlled by inhalers
Chronic spontaneous hives (urticaria)
Nasal polyps (in some countries)

Common brand names

India: Xolair
Worldwide: Xolair

Common side effects

Injection-site reactions
Headache
Joint pain
Sore throat

Before taking it — precautions

Keep using your usual asthma inhalers; it is an add-on
Not for sudden asthma attacks
Tell your doctor about parasitic worm infections or travel to such areas

When to see a doctor urgently

Swelling, wheeze, dizziness or collapse after injection (anaphylaxis) (urgent)
Fever, joint pain and rash a few days after injection
Worsening breathing despite inhalers (urgent)

Not a prescription — no dose shown. The right dose of omalizumab depends on age, weight, kidney/liver function and the condition, so MedDroid does not show a dose here. Always get your dose from a doctor or pharmacist and the leaflet inside the pack. General educational information only.

Frequently asked questions

How does omalizumab work?

It binds IgE, the antibody that drives allergic reactions, which reduces asthma attacks and hives.

Why do I wait after the injection?

Rarely it causes a severe allergic reaction, so the first injections are watched in clinic.

How long before it helps?

Hives can improve within weeks; asthma benefit is usually judged after a few months.

Ask MedDroid about omalizumab →

Explore more

Sources & further reading

Reviewed by Dr. Sanjay Anbu, MBBS. MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.