Emgality vs. Topamax
See how Emgality and Topamax compare on approved uses, dosing, side effects, and cost.
Key Takeaways
Emgality is a once-monthly injection that targets CGRP to prevent migraine, while Topamax is a daily anticonvulsant pill used for migraine prevention and epilepsy.
Emgality is the only FDA-approved drug specifically for preventing episodic cluster headache attacks, a use Topamax does not have.
Topamax is available as a low-cost generic, while Emgality is a newer biologic that typically costs several hundred dollars more per month without insurance.
Emgality vs. Topamax Drug Summary
Emgality
Emgality (galcanezumab-gnlm) is a calcitonin gene-related peptide (CGRP) antagonist used to prevent migraine attacks and to treat episodic cluster headache in adults. It's given as a self-administered subcutaneous injection once a month, using a prefilled pen or syringe.
Topamax
Topamax (topiramate) is an anticonvulsant medication approved to prevent migraine in adults and adolescents 12 and older, and to treat certain seizure types in epilepsy. It's taken as an oral tablet twice a day, after a several-week dose increase to reach the maintenance level.
Emgality vs. Topamax Side Effects
Emgality
Topamax
Emgality vs. Topamax Dosage
Emgality
Topamax
| STAGE | DOSE | WHEN |
| Starting dose | 240 mg | Day 1 |
| Maximum dose | 300 mg once monthly | If needed |
| Dose changes | 2 increases | As tolerated |
| STAGE | DOSE | WHEN |
| Starting dose | 25 mg/day | Week 1 |
| Maximum dose | Up to 200 mg/day | If needed |
| Dose changes | 5 increases | Every week |
Emgality
| STAGE | DOSE | WHEN |
| Starting dose | 240 mg | Day 1 |
| Maximum dose | 300 mg once monthly | If needed |
| Dose changes | 2 increases | As tolerated |
Topamax
| STAGE | DOSE | WHEN |
| Starting dose | 25 mg/day | Week 1 |
| Maximum dose | Up to 200 mg/day | If needed |
| Dose changes | 5 increases | Every week |
Emgality vs. Topamax Indications
Emgality
Emgality is FDA-approved to reduce how often migraine attacks happen in adults and, separately, to treat episodic cluster headache in adults. It was the first medication approved specifically for preventing episodic cluster headache attacks. It is not approved for children or for stopping a migraine once it has started.
Preventive treatment of migraine in adults
Treatment of episodic cluster headache in adults
Not approved for children under 18
Not approved for acute migraine treatment
Topamax
Topamax is FDA-approved to prevent migraine headaches in adults and adolescents age 12 and up. It's also approved to treat certain seizure types in epilepsy, as monotherapy and as add-on therapy. Some clinicians prescribe it off-label for weight management or mood disorders, uses the FDA has not reviewed for that purpose.
Migraine prevention in adults and adolescents 12+
Monotherapy or add-on therapy for certain seizures
Seizures associated with Lennox-Gastaut syndrome
Off-label: weight loss or bipolar disorder (not FDA-approved)
Emgality vs. Topamax Pros and Cons
Emgality
Emgality's once-monthly injection and targeted mechanism make it a newer option for people who haven't done well on oral preventives. It carries no boxed warning, but as a specialty biologic it often needs prior authorization and costs considerably more than older generic pills like topiramate.
Pros
Only one injection needed per month
Only FDA-approved drug shown to reduce episodic cluster headache attacks
Not linked to cognitive side effects like memory or word-finding problems
No warning for birth defects
Cons
Typically costs $650 to $900 per month without insurance, much more than generic topiramate
Can cause injection site reactions in up to 18% of patients
May worsen or trigger Raynaud's phenomenon
Often needs prior authorization from insurers
Topamax
Topamax has decades of use behind it and is widely available as an inexpensive generic tablet. Its trade-off is a multi-week titration, a high rate of tingling sensations, and warnings around cognitive slowing and birth defects that require monitoring.
Pros
Available as a generic for roughly $20 to $100 per month without insurance, far cheaper than Emgality
Oral tablet, no injections needed
Also treats epilepsy, useful if a patient has both conditions
Decades of real-world prescribing experience
Cons
Requires twice-daily dosing with a multi-week dose increase
Paresthesia (tingling) affects up to half of patients
Carries warnings for cognitive slowing and kidney stones
Carries a class warning for increased suicidal thoughts
Common Symptoms and Related Diseases You Can Explore
Explore a range of common symptoms the Doctronic Symptom Checker can help you understand.