Two medicines, side by side
Carbamazepine vs risperidone
Carbamazepine and risperidone are both labeled for bipolar disorder. Drugs@FDA records approvals of carbamazepine since 1968 and of risperidone since 1993. Pharmacies paid $0.119 per carbamazepine 200 mg tablet and $0.0368 per risperidone 0.25 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 risperidone an atypical antipsychotic.
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026); the risperidone FDA label on DailyMed (effective May 28, 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 risperidone record
Risperidone (Risperdal) · label of May 28, 2026
INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. RISPERDAL is not approved for the treatment of patients with dementia-related psychosis. [see Warnings and Precautions (5.1) ] WARNING: INCREASED MORTALITY IN ELDERLY PATIENTS WITH DEMENTIA-RELATED PSYCHOSIS See full prescribing information for complete boxed warning.
Used for
From the label: indicationsRISPERDAL is an atypical antipsychotic indicated for: Treatment of schizophrenia ( 1.1 ) As monotherapy or adjunctive therapy with lithium or valproate, for the treatment of acute manic or mixed episodes associated with Bipolar I Disorder ( 1.2 ) Treatment of irritability associated with autistic disorder ( 1.3 ) 1.1 Schizophrenia RISPERDAL (risperidone) is indicated for the treatment of schizophrenia. […]
On the market
- Earliest approval on file
- December 29, 1993
- Generic labelers
- 37 labelers
- Pharmacy cost
- $0.0368 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 5
Source: FDA drug labels via openFDA (Carbamazepine label of August 20, 2026, Risperidone label of May 28, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do carbamazepine and risperidone differ on the record?
In FDA's classes, carbamazepine is a mood stabilizer and risperidone an atypical antipsychotic.
How each works, in its label's words: Carbamazepine, “It appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation.”; Risperidone, “The drug's therapeutic activity in schizophrenia could be mediated through a combination of dopamine Type 2 (D 2 ) and serotonin Type 2 (5HT 2 ) receptor antagonism.”
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.”; Risperidone, “The apparent half-life of risperidone was 3 hours (CV=30%) in extensive metabolizers and 20 hours (CV=40%) in poor …”
Both labels carry a boxed warning; the records quote them.
Generics: carbamazepine since 1986; risperidone since 2008 (Drugs@FDA).
| Carbamazepine | Risperidone | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Bipolar disorder, Schizophrenia |
| Pharmacologic class | Mood Stabilizer | Atypical Antipsychotic |
| 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 mechanism of action of risperidone in schizophrenia is unclear. The drug's therapeutic activity in schizophrenia could be mediated through a combination of dopamine Type 2 (D 2 ) and serotonin Type 2 (5HT 2 ) receptor antagonism. |
| Half-life (label) | Initial half-life values range from 25 to 65 hours, decreasing to 12 to 17 hours on repeated doses. | The apparent half-life of risperidone was 3 hours (CV=30%) in extensive metabolizers and 20 hours (CV=40%) in poor metabolizers. |
| Earliest approval on file (Drugs@FDA) | March 11, 1968 | December 29, 1993 |
| First generic approved | August 14, 1986 | June 30, 2008 |
| Generic labelers (NDC) | 42 labelers | 37 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.119 per tablet (Carbamazepine 200 mg tablet) | $0.0368 per tablet (Risperidone 0.25 mg tablet) |
| 12-month price change | +0.6% | -13% |
| Boxed warning | Yes | Yes |
| Shortage now | A presentation being discontinued | No current entry |
| Recalls recorded | 11 | 5 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 66,615 | 131,095 |
| 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… olanzapine, oral and other hormonal contraceptives, oxcarbazepine, 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… olanzapine, oral and other hormonal contraceptives (2), oxcarbazepine, paliperidone, phenytoin (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. …
Risperidone label, drug interactionsDRUG INTERACTIONS Carbamazepine and other enzyme inducers decrease plasma concentrations of risperidone.
Risperidone label, drug interactions… ) Clozapine may decrease clearance of risperidone. ( 7.7 ) Fluoxetine and paroxetine increase plasma concentrations of risperidone. ( 7.12 ) Carbamazepine and other enzyme inducers decrease plasma concentrations of risperidone.
Source: FDA drug labels via openFDA
What next?
- Alternatives to carbamazepine
- every medicine labeled for the same conditions