CGRP Receptor Monoclonal Antibody — Migraine Prevention Pregnancy: Avoid — insufficient data; discontinue if pregnancy planned

Erenumab

Brand names: Aimovig

Adult dose

Dose: 70 mg SC monthly; may increase to 140 mg monthly if inadequate response

Route: Subcutaneous (self-administered autoinjector)

Frequency: Once monthly

Max: 140 mg/month

First-in-class anti-CGRP receptor monoclonal antibody for migraine prevention. NICE approved for adults with ≥4 migraine days/month who have failed ≥3 preventive treatments. Treatment trial: minimum 3 months at 70 mg; if no response, increase to 140 mg for further 3 months. Reassess every 12 months.

Paediatric dose

Route:

Seek specialist opinion — not licensed in patients under 18 years.

Dose adjustments

Renal

No dose adjustment required.

Hepatic

No dose adjustment required — degraded by proteolytic enzymes, not CYP450.

Clinical pearls

CGRP is released from trigeminal nerve terminals during migraine — blocking its receptor prevents neurogenic inflammation and vasodilation central to migraine pathophysiology
ARISE and STRIVE trials: 50% responder rates of ~40–45% vs ~25% placebo — clinically meaningful reduction in monthly migraine days
NICE NG218: erenumab approved for chronic migraine (≥15 headache days/month) or episodic migraine (4–14 days/month) having failed ≥3 preventives. Stop after 12 weeks if no benefit.

Contraindications

Hypersensitivity to erenumab
Severe constipation or bowel obstruction (CGRP has prokinetic role in gut — relative contraindication)

Side effects

Injection site reactions (pain, erythema)
Constipation (clinically significant in some — CGRP role in gut motility)
Hypertension (monitor)
Pruritus
Muscle cramps

Interactions

No significant drug interactions — monoclonal antibody not CYP450 metabolised

Monitoring

Monthly migraine day diary
Blood pressure (hypertension risk)
Bowel function (constipation)
Response assessment at 3 months

Reference: BNFc; BNF 90; NICE NG218 (Migraine); ARISE Trial; STRIVE Trial (NEJM 2017). Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways