Erenumab
CGRP antagonists (gepants and anti-CGRP antibodies)
CGRP antagonists (gepants and anti-CGRP antibodies)
A monthly injected monoclonal antibody that blocks the CGRP receptor and prevents migraine; it does not treat an attack under way.
Also called: Erenumab-aooe
Quick facts
- Group
- CGRP antagonists (gepants and anti-CGRP antibodies)
- Target
- CGRP receptor (calcitonin receptor-like receptor, CALCRL)
- Used for
- Prevention of migraine in adults
- Key effects
- Injection site pain · Constipation
- Monitor
- Blood pressure at follow-up visits · Bowel habits
- ATC
- N02CD01
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows the Fab fragment of erenumab bound to the extracellular domain of the human CGRP receptor; the drug is the antibody itself, so there is no small ligand.
Erenumab is a monoclonal antibody that binds the CGRP receptor and stops calcitonin gene-related peptide from activating it. CGRP, released by trigeminal nerves, dilates vessels and promotes neurogenic inflammation during migraine; blocking its receptor lowers the number of migraine days over time.
- Erenumab binds the CGRP receptor
- CGRP released by trigeminal nerves cannot signal
- Less vasodilation and neurogenic inflammation
- Fewer migraine days over the following months
Indications
- Prevention of migraine in adults Migraine →
Adverse effects
Common
- Injection site pain, redness, swelling or itching
- Constipation
- Muscle cramps or spasms
Contraindications
- Hypersensitivity to erenumab or its components
Key interactions
- Acute migraine medicines (triptans, analgesics)
- Still needed for attacks: erenumab prevents migraine but does not stop an attack under way
What is monitored
- Blood pressure at follow-up visits
- Bowel habits
- Headache diary to judge benefit
Administration and safety
- Kept in the refrigerator; warmed to room temperature for about 30 minutes before injecting, never heated
- Not shaken; not used if dropped, cloudy, coloured or with particles
- Injected under the skin of the thigh or abdomen (upper arm if a caregiver injects)
Nursing care
- Teach injection technique and safe disposal of needles
- Ask about hypertension and Raynaud phenomenon before starting
- Advise reporting severe constipation or abdominal pain
- Remind that acute attack medicines are still needed
Pharmacokinetics
- Absorption
- Subcutaneous injection
- Elimination
- Long-acting antibody, given once a month
Test yourself
Think of the answer, then tap the question to see it.
What does erenumab bind?
The CGRP receptor (not the CGRP peptide).
Is erenumab used to treat an acute migraine attack?
No; it is a monthly preventive treatment.
Which two adverse effects of erenumab are watched at follow-up?
Constipation and high blood pressure.
Connections
← Back to the class: CGRP antagonists (gepants and anti-CGRP antibodies)
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Erenumab-aooe Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); RCSB PDB - 6UMG: Crystal structure of erenumab Fab bound to the extracellular domain of CGRP receptor (RCSB Protein Data Bank, 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.