Ajovy vs. Topamax

See how Ajovy and Topamax compare on approved uses, dosing, side effects, and cost.

Key Takeaways

  • Ajovy is an injectable CGRP antibody given once a month or once every 3 months, while Topamax is a daily pill that requires several weeks of dose titration.

  • Ajovy's main side effect is injection site reactions, while Topamax more often causes tingling, fatigue, appetite loss, and thinking-related side effects.

  • Topamax has a low-cost generic version, while Ajovy has no generic and typically costs far more per month out of pocket.

Ajovy vs. Topamax Drug Summary

Ajovy

Ajovy is a CGRP monoclonal antibody used to prevent migraines in adults and in children 6 and older who weigh at least 45 kg. It's given as a subcutaneous injection either once a month or once every three months. It works by blocking a protein involved in triggering migraine attacks, rather than treating an attack once it starts.

Topamax

Topamax is an anticonvulsant, also FDA-approved to prevent migraines in people 12 and older. It's taken as a daily oral tablet or capsule, starting at a low dose that's slowly raised over several weeks to limit side effects. It's also used to treat certain types of epilepsy.

Ajovy vs. Topamax Side Effects

Ajovy

Most common
Injection site reactions (38% to 45%)

Topamax

Most common
Paresthesia (up to 51%)

Ajovy vs. Topamax Dosage

Ajovy

Dosage
Dosage Table
STAGE DOSE WHEN
Starting dose 225 mg once monthly At the start
Maximum dose 675 mg every 3 months If needed
Dose changes 1 increase As tolerated

Topamax

Dosage
Dosage Table
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

Ajovy vs. Topamax Indications

Ajovy

Ajovy is FDA-approved to prevent migraines before they start, not to stop an attack already underway. It's approved for adults and for adolescents 6 to 17 years old who weigh at least 45 kg. It isn't approved for younger or lighter-weight children.

  • Preventive treatment of migraine in adults

  • Preventive treatment of episodic migraine in patients 6 to 17 years old weighing at least 45 kg

  • Not approved for acute (in-the-moment) migraine treatment

  • Not approved for children under 6 years old or under 45 kg

Topamax

Topamax is FDA-approved to prevent migraines in people 12 and older, and it also treats several types of epilepsy. Like Ajovy, it isn't approved to stop a migraine once it has already started. Doctors sometimes prescribe it off-label for other conditions, such as weight management, but that use isn't FDA-approved.

  • Preventive treatment of migraine in patients 12 years and older

  • Treatment of partial-onset seizures and primary generalized tonic-clonic seizures

  • Adjunctive treatment of seizures associated with Lennox-Gastaut syndrome

  • Off-label: sometimes prescribed for weight management, though not FDA-approved for this use

Ajovy vs. Topamax Pros and Cons

Ajovy

Ajovy trades a daily pill for an infrequent injection and has a side effect profile centered almost entirely on the injection site. Because it's a newer biologic with no generic, insurers often require patients to try cheaper options first, and it costs substantially more out of pocket.

Pros

  • Only needs to be injected once a month, or once every 3 months

  • No daily pill or multi-week dose titration required

  • Not linked to cognitive side effects like brain fog or word-finding trouble

  • Approved for adolescents 6 to 17 years old with episodic migraine

Cons

  • Injection site reactions occur in a large share of patients

  • No generic version is currently available

  • Costs roughly $690 to $1,046 per month without insurance, before savings programs

  • Can cause or worsen Raynaud's phenomenon

Topamax

Topamax is a well-established, inexpensive option with decades of use, but it requires a slow daily dose increase and carries a distinct set of thinking-related and pregnancy risks. Its cognitive side effects are a common reason patients discontinue it.

Pros

  • Available as a low-cost generic tablet or capsule

  • Generic topiramate typically costs roughly $20 to $100 per month without insurance

  • Also FDA-approved to treat several types of epilepsy

  • Long track record of clinical use since its 1996 approval

Cons

  • Requires a multi-week dose titration before reaching a maintenance dose

  • Commonly causes tingling sensations (paresthesia) in over half of patients

  • Associated with cognitive side effects like slowed thinking or word-finding trouble

  • Carries a pregnancy warning for increased risk of birth defects such as cleft palate

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