Two medicines, side by side
Topiramate vs valproic acid
Topiramate and valproic acid are both labeled for seizures and epilepsy and migraine. Drugs@FDA records approvals of topiramate since 1996 and of valproic acid since 1978. Pharmacies paid $0.0567 per topiramate 100 mg tablet and $0.243 per valproic acid 250 mg capsule (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. Only the valproic acid label carries a boxed warning.
Check it at the source: the topiramate FDA label on DailyMed (effective June 1, 2026); the valproic acid FDA label on DailyMed (effective January 24, 2025).
Highlights of the topiramate record
Topiramate (Topamax) · label of June 1, 2026
Used for
From the label: indicationsTopiramate is indicated for: Epilepsy: initial monotherapy for the treatment of partial-onset or primary generalized tonic-clonic seizures in patients 2 years of age and older (1.1); adjunctive therapy for the treatment of partial-onset seizures, primary generalized tonic-clonic seizures, or seizures associated with Lennox- Gastaut syndrome in patients 2 years of age and older (1.2) Preventive treatment of migraine […]
On the market
- Earliest approval on file
- December 24, 1996
- Generic labelers
- 47 labelers
- Pharmacy cost
- $0.0567 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 10
Highlights of the valproic acid record
Valproic acid (Depakene) · label of January 24, 2025
LIFE THREATENING ADVERSE REACTIONS WARNING: LIFE THREATENING ADVERSE REACTIONS See full prescribing information for complete boxed warning. Hepatotoxicity, including fatalities, usually during the first 6 months of treatment. Children under the age of two years and patients with mitochondrial disorders are at higher risk.
Used for
From the label: indicationsValproic acid is indicated for: Monotherapy and adjunctive therapy of complex partial seizures; sole and adjunctive therapy of simple and complex absence seizures; adjunctive therapy in patients with multiple seizure types that include absence seizures ( 1 ) 1.1 Epilepsy Valproic acid is indicated as monotherapy and adjunctive therapy in the treatment of patients with complex partial seizures that occur either in isolation or in association with other types of seizures. […]
On the market
- Earliest approval on file
- February 28, 1978
- Generic labelers
- 22 labelers
- Pharmacy cost
- $0.243 per capsule
Supply and safety
- Shortage
- Listed; available
- Recalls
- 2
Source: FDA drug labels via openFDA (Topiramate label of June 1, 2026, Valproic acid label of January 24, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do topiramate and valproic acid differ on the record?
Only the valproic acid label carries a boxed warning.
How each works, in its label's words: Topiramate, “The precise mechanisms by which topiramate exerts its anticonvulsant and preventive migraine effects are unknown; however, preclinical studies have revealed four properties that may contribute to …”; Valproic acid, “Valproic acid dissociates to the valproate ion in the gastrointestinal tract.”
Half-life, in each label's words: Topiramate, “The mean plasma elimination half-life is 21 hours after single or multiple doses.”; Valproic acid, “Mean terminal half-life for valproate monotherapy ranged from 9 to 16 hours following oral dosing regimens of 250 to …”
Generics: topiramate since 2003; valproic acid since 1986 (Drugs@FDA).
| Topiramate | Valproic acid | |
|---|---|---|
| Labeled for | Seizures and epilepsy, Migraine | Seizures and epilepsy, Migraine |
| Pharmacologic class | n/a | Anti-epileptic Agent, Mood Stabilizer |
| How it works (label) | The precise mechanisms by which topiramate exerts its anticonvulsant and preventive migraine effects are unknown; however, preclinical studies have revealed four properties that may contribute to topiramate's efficacy for epilepsy and the … | Valproic acid dissociates to the valproate ion in the gastrointestinal tract. The mechanisms by which valproate exerts its therapeutic effects have not been established. |
| Half-life (label) | The mean plasma elimination half-life is 21 hours after single or multiple doses. | Mean terminal half-life for valproate monotherapy ranged from 9 to 16 hours following oral dosing regimens of 250 to 1,000 mg. |
| Earliest approval on file (Drugs@FDA) | December 24, 1996 | February 28, 1978 |
| First generic approved | December 17, 2003 | February 28, 1986 |
| Generic labelers (NDC) | 47 labelers | 22 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0567 per tablet (Topiramate 100 mg tablet) | $0.243 per capsule (Valproic acid 250 mg capsule) |
| 12-month price change | -10% | -4% |
| Boxed warning | No | Yes |
| Shortage now | No current entry | Listed; available |
| Recalls recorded | 10 | 2 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 91,067 | 51,380 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
Do their labels mention each other?
Topiramate label, drug interactionsConcomitant administration of valproic acid and topiramate has been associated with hypothermia and hyperammonemia with and without encephalopathy.
Topiramate label, warnings and precautions… patients on a ketogenic diet (5.15) Hypothermia has been reported with and without hyperammonemia during topiramate treatment with concomitant valproic acid use
Valproic acid label, drug interactions… adjustment of amitriptyline/nortriptyline, propofol, warfarin, and zidovudine may be necessary if used concomitantly with Valproic acid ( 7.2 ) Topiramate: Hyperammonemia and encephalopathy
Valproic acid label, warnings and precautionsAntiepileptic drugs, including valproic acid, increase the risk of suicidal thoughts or behavior ( 5.7 ) Bleeding and other hematopoietic disorders; monitor platelet counts and coagulation tests ( 5.8 ) Hyperammonemia and hyperammonemic encephalopathy; measure ammonia level if unexplained lethargy and vomiting or changes in mental status, and also with concomitant topiramate use; …
Source: FDA drug labels via openFDA
What do the labels say about using others of their kind?
Topiramate label, drug interactionsBecause of the potential of topiramate to cause CNS depression, as well as other cognitive and/or neuropsychiatric adverse reactions, topiramate should be used with extreme caution if used in combination with alcohol and other CNS depressants.
Source: FDA drug labels via openFDA
What next?
- Alternatives to topiramate
- every medicine labeled for the same conditions