Two medicines, side by side
Carbamazepine vs clonazepam
Carbamazepine and clonazepam are both labeled for seizures and epilepsy. Drugs@FDA records approvals of carbamazepine since 1968 and of clonazepam since 1975. Pharmacies paid $0.119 per carbamazepine 200 mg tablet and $0.0244 per clonazepam 1 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, carbamazepine is a mood stabilizer and clonazepam a benzodiazepine.
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026); the clonazepam FDA label on DailyMed (effective December 1, 2025).
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 clonazepam record
Clonazepam (Klonopin) · label of December 1, 2025
RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required.
Used for
From the label: indicationsSeizure Disorders Klonopin is useful alone or as an adjunct in the treatment of the Lennox-Gastaut syndrome (petit mal variant), akinetic, and myoclonic seizures. In patients with absence seizures (petit mal) who have failed to respond to succinimides, Klonopin may be useful. Some loss of effect may occur during the course of clonazepam treatment (see PRECAUTIONS: Loss of Effect ). […]
On the market
- Earliest approval on file
- June 4, 1975
- Generic labelers
- 31 labelers
- Pharmacy cost
- $0.0244 per tablet
Supply and safety
- Shortage
- In shortage
- Recalls
- 7
Source: FDA drug labels via openFDA (Carbamazepine label of August 20, 2026, Clonazepam label of December 1, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do carbamazepine and clonazepam differ on the record?
In FDA's classes, carbamazepine is a mood stabilizer and clonazepam a benzodiazepine.
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.”; Clonazepam, “The elimination half-life of clonazepam is typically 30 to 40 hours.”
Both labels carry a boxed warning; the records quote them.
Generics: carbamazepine since 1986; clonazepam since 1996 (Drugs@FDA).
DEA schedule: carbamazepine none; clonazepam CIV.
| Carbamazepine | Clonazepam | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Seizures and epilepsy, Anxiety |
| Pharmacologic class | Mood Stabilizer | Benzodiazepine |
| 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. | n/a |
| Half-life (label) | Initial half-life values range from 25 to 65 hours, decreasing to 12 to 17 hours on repeated doses. | The elimination half-life of clonazepam is typically 30 to 40 hours. |
| Earliest approval on file (Drugs@FDA) | March 11, 1968 | June 4, 1975 |
| First generic approved | August 14, 1986 | September 10, 1996 |
| Generic labelers (NDC) | 42 labelers | 31 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.119 per tablet (Carbamazepine 200 mg tablet) | $0.0244 per tablet (Clonazepam 1 mg tablet) |
| 12-month price change | +0.6% | -14% |
| Boxed warning | Yes | Yes |
| Shortage now | A presentation being discontinued | In shortage |
| Recalls recorded | 11 | 7 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 66,615 | 159,283 |
| DEA schedule | none | CIV |
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 interactionsIn addition, Tegretol causes, or would be expected to cause, decreased levels of the following drugs, for which monitoring of concentrations or dosage adjustment may be necessary: acetaminophen, albendazole, alprazolam, aprepitant, buprenorphone, bupropion, citalopram, clonazepam, clozapine, corticosteroids (e.g., prednisolone, dexamethasone), cyclosporine, dicumarol, dihydropyridine calcium channel blockers (e.g. …
Carbamazepine label, drug interactionsAcetaminophen, albendazole, alprazolam, aprepitant, buprenorphine, apixaban (6), bupropion, buspirone, citalopram, clobazam, clonazepam, clozapine, corticosteroids (e.g. prednisolone, dexamethasone), cyclosporin, dabigatran (6), delavirdine, desipramine, diazepam, dicumarol, dihydropyridine calcium channel blockers (e.g., felodipine), doxycycline, edoxaban (6), eslicarbazepine, ethosuximide, everolimus, felbamate …
Clonazepam label, drug interactionsCytochrome P-450 inducers, such as phenytoin, carbamazepine, lamotrigine, and phenobarbital induce clonazepam metabolism, causing an approximately 38% decrease in plasma clonazepam levels.
Source: FDA drug labels via openFDA
What next?
- Alternatives to carbamazepine
- every medicine labeled for the same conditions