Eptinezumab

Eptinezumab is a humanised monoclonal antibody against the calcitonin gene-related peptide ligand, given as an intravenous infusion once every 3 months for prevention of migraine. It acts from the first day, and the infusion ensures full delivery and adherence.

Mechanism. Binds calcitonin gene-related peptide, preventing activation of its receptor and reducing trigeminal pain signalling.

Pharmacokinetics. Intravenous administration gives complete bioavailability. Half-life is about 27 days. It is cleared by general protein breakdown, with no cytochrome P450 or kidney interactions.

Specialist use. Preventive treatment of migraine in adults.

• Intravenous eptinezumab: 100 mg once every 3 months. Some people benefit from 300 mg once every 3 months, which is the maximum.

• Review benefit after 3 months, and stop if there is no response by 6 months.

Kidney, liver, weight and age.

• Kidney and liver: no adjustment.

• Older adults: limited data over age 65.

• Children: not licensed under 18 years.

Contraindications. Hypersensitivity.

Serious adverse effects. Infusion-related hypersensitivity (angioedema, urticaria, flushing, rash, dyspnoea), occurring during infusion or soon after. Hypertension and Raynaud phenomenon are reported.

Common adverse effects. Nasopharyngitis, hypersensitivity reactions, fatigue and nausea.

Interactions. No clinically important interactions are described.

Common prescribing errors. Giving a bolus instead of an infusion. Not observing during and after the infusion. Continuing without a benefit review.

Special groups.

• Pregnancy: avoid unless clearly needed.

• Breastfeeding: no data; use with caution.

• Regional: very costly and seldom available, and it needs infusion facilities and cold storage.

Formulations. Single-dose vial 100 mg in 1 mL. Store at 2 to 8 degrees Celsius, protected from light. Do not shake.

Preparation. Dilute the dose in 100 mL of 0.9% sodium chloride and infuse over 30 minutes through a line with a 0.2 micron filter. Flush with 0.9% sodium chloride after the infusion.

Monitoring.

• Blood pressure and signs of hypersensitivity during and after the infusion.

• Headache diary of monthly migraine days, with review at 3 months and about every 6 to 12 months.

Stopping. No taper is needed.

Referral and escalation. Start under specialist care. Treat hypersensitivity as an emergency, and stop the infusion.