erenumab
Brand: Aimovig
Prototype Drug
Drug Class: anti-CGRP receptor monoclonal antibody
Drug Family: antimigraine
Subclass: fully human IgG2 anti-CGRP receptor antibody
Organ Systems: cns
Mechanism of Action
Fully human monoclonal antibody that specifically binds and blocks the CGRP receptor, preventing CGRP-mediated vasodilation and trigeminal sensitization. Unlike gepants (small molecules), erenumab is a biologic with monthly subcutaneous dosing and a prolonged effect due to antibody half-life. First CGRP pathway-targeted migraine prevention drug approved.
CGRP receptor (calcitonin gene-related peptide receptor)
Indications
- preventive treatment of migraine in adults (episodic and chronic)
Contraindications
- hypersensitivity to erenumab
Adverse Effects
Common
- injection site reactions
- constipation
- pruritus
- nasopharyngitis
Serious
- severe constipation requiring hospitalization (rare)
- hypertension (rarely significant)
- hypersensitivity reactions
Pharmacokinetics (ADME)
| Absorption | subcutaneous; bioavailability ~82% |
| Distribution | Vd ~3.86 L |
| Metabolism | proteolytic degradation to peptides and amino acids (monoclonal antibody catabolism) |
| Excretion | not renally cleared to significant extent |
| Half-life | 28 days |
| Onset | clinical benefit may begin within 1-3 months |
| Peak | 6 days after SC injection |
| Duration | monthly dosing (70 mg or 140 mg SC) |
| Protein Binding | not applicable for mAb |
| Vd | 3.86 L |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| none significant CYP-based | no CYP450-mediated interactions (monoclonal antibody) | minor |
Nursing Considerations
- Self-administered SC injection monthly; teach injection technique, site rotation (abdomen, thigh, upper arm), and cold chain storage.
- Constipation can be severe and may require dose reduction or discontinuation; educate about hydration, dietary fiber, and laxatives.
- Allow autoinjector to reach room temperature 30 minutes before administration; do not shake; inspect for particulates before injection.
- Clinical response assessment at 3-6 months; discontinue if no meaningful reduction in migraine frequency.
Clinical Pearls
- Erenumab was the first FDA-approved drug developed specifically targeting CGRP pathophysiology for migraine prevention, representing a disease-mechanism-specific therapy rather than drugs repurposed from other indications (beta-blockers, anticonvulsants, tricyclics).
- The anti-CGRP antibody class (erenumab, fremanezumab, galcanezumab, eptinezumab) has transformed migraine prevention by offering monthly or quarterly dosing with better tolerability than traditional preventives.
Safety Profile
Pregnancy avoid
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Guideline Update pending
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.