galcanezumab
Brand: Emgality
Prototype: erenumab
Drug Class: anti-CGRP monoclonal antibody
Drug Family: antimigraine
Subclass: humanized IgG4 anti-CGRP ligand antibody
Organ Systems: cns
Mechanism of Action
Humanized monoclonal antibody that binds CGRP ligand, preventing receptor activation and downstream trigeminal sensitization. Also has an FDA indication for episodic cluster headache — the first pharmacological preventive for this condition.
CGRP ligand
Indications
- preventive treatment of migraine in adults
- preventive treatment of episodic cluster headache (adults)
Contraindications
- hypersensitivity to galcanezumab
Adverse Effects
Common
- injection site reactions
- constipation
- pruritus
Serious
- hypersensitivity reactions
Pharmacokinetics (ADME)
| Absorption | subcutaneous; bioavailability ~90% |
| Distribution | Vd ~7.3 L |
| Metabolism | proteolytic degradation |
| Excretion | catabolism |
| Half-life | 27 days |
| Onset | migraine benefit within 1 month |
| Peak | 5 days |
| Duration | monthly dosing (120 mg; loading dose 240 mg first month) |
| Protein Binding | not applicable |
| Vd | 7.3 L |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| none significant | no CYP450 interactions | minor |
Nursing Considerations
- Loading dose of 240 mg (2 x 120 mg injections) required at initiation for migraine; thereafter 120 mg monthly.
- For cluster headache: 300 mg/month (3 x 100 mg injections) during cluster period.
- Allow autoinjector to warm to room temperature 30 minutes before use; do not shake.
- Assess therapeutic response at 3 months; about 50% of patients achieve >50% reduction in monthly migraine days.
Clinical Pearls
- Galcanezumab is the only anti-CGRP monoclonal antibody with FDA approval for episodic cluster headache, offering the first pharmacological preventive specifically approved for this exquisitely painful headache disorder.
- The loading dose of 240 mg at initiation of migraine prevention with galcanezumab accelerates achievement of therapeutic CGRP neutralization, providing faster onset of migraine frequency reduction than waiting for monthly dosing to reach steady state.
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.