Two medicines, side by side
Carbamazepine vs topiramate
Carbamazepine and topiramate are both labeled for seizures and epilepsy. Drugs@FDA records approvals of carbamazepine since 1968 and of topiramate since 1996. Pharmacies paid $0.119 per carbamazepine 200 mg tablet and $0.0567 per topiramate 100 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. Only the carbamazepine label carries a boxed warning.
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026); the topiramate FDA label on DailyMed (effective June 1, 2026).
Highlights of the carbamazepine record
Carbamazepine (Tegretol) · label of August 20, 2026
SERIOUS DERMATOLOGIC REACTIONS AND HLA-B*1502 ALLELE SERIOUS AND SOMETIMES FATAL DERMATOLOGIC REACTIONS, INCLUDING TOXIC EPIDERMAL NECROLYSIS (TEN) AND STEVENS-JOHNSON SYNDROME (SJS), HAVE BEEN REPORTED DURING TREATMENT WITH TEGRETOL. THESE REACTIONS ARE ESTIMATED TO OCCUR IN 1 TO 6 PER 10,000 NEW USERS IN COUNTRIES WITH MAINLY CAUCASIAN POPULATIONS, BUT THE RISK IN SOME ASIAN COUNTRIES IS ESTIMATED TO BE ABOUT 10 TIMES HIGHER.
Used for
From the label: indicationsEpilepsy Tegretol is indicated for use as an anticonvulsant drug. Evidence supporting efficacy of Tegretol as an anticonvulsant was derived from active drug-controlled studies that enrolled patients with the following seizure types: Partial seizures with complex symptomatology (psychomotor, temporal lobe). Patients with these seizures appear to show greater improvement than those with other types. […]
On the market
- Earliest approval on file
- March 11, 1968
- Generic labelers
- 42 labelers
- Pharmacy cost
- $0.119 per tablet
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 11
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
Source: FDA drug labels via openFDA (Carbamazepine label of August 20, 2026, Topiramate label of June 1, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do carbamazepine and topiramate differ on the record?
Only the carbamazepine label carries a boxed warning.
How each works, in its label's words: Carbamazepine, “It appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation.”; 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 …”
Half-life, in each label's words: Carbamazepine, “Initial half-life values range from 25 to 65 hours, decreasing to 12 to 17 hours on repeated doses.”; Topiramate, “The mean plasma elimination half-life is 21 hours after single or multiple doses.”
Generics: carbamazepine since 1986; topiramate since 2003 (Drugs@FDA).
| Carbamazepine | Topiramate | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Seizures and epilepsy, Migraine |
| Pharmacologic class | Mood Stabilizer | n/a |
| How it works (label) | Mechanism of Action Tegretol has demonstrated anticonvulsant properties in rats and mice with electrically and chemically induced seizures. It appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation. | 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 … |
| Half-life (label) | Initial half-life values range from 25 to 65 hours, decreasing to 12 to 17 hours on repeated doses. | The mean plasma elimination half-life is 21 hours after single or multiple doses. |
| Earliest approval on file (Drugs@FDA) | March 11, 1968 | December 24, 1996 |
| First generic approved | August 14, 1986 | December 17, 2003 |
| Generic labelers (NDC) | 42 labelers | 47 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.119 per tablet (Carbamazepine 200 mg tablet) | $0.0567 per tablet (Topiramate 100 mg tablet) |
| 12-month price change | +0.6% | -10% |
| Boxed warning | Yes | No |
| Shortage now | A presentation being discontinued | No current entry |
| Recalls recorded | 11 | 10 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 66,615 | 91,067 |
| 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?
Carbamazepine label, drug interactions… paliperidone, phensuximide, phenytoin, praziquantel, protease inhibitors, risperidone, sertraline, sirolimus, tadalafil, theophylline, tiagabine, topiramate, tramadol, trazodone, tricyclic antidepressants (e.g., imipramine, amitriptyline, nortriptyline), valproate, warfarin, ziprasidone, zonisamide.
Carbamazepine label, drug interactions… (3), praziquantel, protease inhibitors, quetiapine, risperidone, rivaroxaban (6), sertraline, sirolimus, tadalafil, theophylline, tiagabine, topiramate, tramadol, triazolam, trazodone (4), tricyclic antidepressants (e.g., imipramine, amitriptyline, nortriptyline), valproate, warfarin (5), ziprasidone, and zonisamide. …
Topiramate label, drug interactionsConcomitant administration of phenytoin or carbamazepine with topiramate resulted in a clinically significant decrease in plasma concentrations of topiramate when compared to topiramate given alone.
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 carbamazepine
- every medicine labeled for the same conditions