Two medicines, side by side
Carbamazepine vs olanzapine
Carbamazepine and olanzapine are both labeled for bipolar disorder. Drugs@FDA records approvals of carbamazepine since 1968 and of olanzapine since 1996. Pharmacies paid $0.119 per carbamazepine 200 mg tablet and $0.147 per olanzapine 20 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 olanzapine an atypical antipsychotic.
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026); the olanzapine FDA label on DailyMed (effective March 5, 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 olanzapine record
Olanzapine (Zyprexa) · label of March 5, 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. Analyses of seventeen placebo-controlled trials (modal duration of 10 weeks), largely in patients taking atypical antipsychotic drugs, revealed a risk of death in drug-treated patients of between 1.6 to 1.7 times the risk of death in placebo-treated patients.
Used for
From the label: indicationsOlanzapine is an atypical antipsychotic indicated: As oral formulation for the: · Treatment of schizophrenia. ( 1.1 ) · Adults: Efficacy was established in three clinical trials in patients with schizophrenia: two 6-week trials and one maintenance trial. ( 14.1 ) · Adolescents (ages 13-17): Efficacy was established in one 6-week trial in patients with schizophrenia ( 14.1 ). […]
On the market
- Earliest approval on file
- September 30, 1996
- Generic labelers
- 43 labelers
- Pharmacy cost
- $0.147 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 14
Source: FDA drug labels via openFDA (Carbamazepine label of August 20, 2026, Olanzapine label of March 5, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do carbamazepine and olanzapine differ on the record?
In FDA's classes, carbamazepine is a mood stabilizer and olanzapine 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.”; Olanzapine, “The mechanism of action of olanzapine, in the listed indications is unclear.”
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.”; Olanzapine, “Its half-life ranges from 21 to 54 hours (5th to 95th percentile; mean of 30 hr), and apparent plasma clearance ranges …”
Both labels carry a boxed warning; the records quote them.
Generics: carbamazepine since 1986; olanzapine since 2011 (Drugs@FDA).
| Carbamazepine | Olanzapine | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Schizophrenia, Bipolar disorder, Depression |
| 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 olanzapine, in the listed indications is unclear. However, the efficacy of olanzapine in schizophrenia could be mediated through a combination of dopamine and serotonin type 2 (5HT 2 ) antagonism. |
| Half-life (label) | Initial half-life values range from 25 to 65 hours, decreasing to 12 to 17 hours on repeated doses. | Its half-life ranges from 21 to 54 hours (5th to 95th percentile; mean of 30 hr), and apparent plasma clearance ranges from 12 to 47 L/hr (5th to 95th percentile; mean of 25 L/hr). |
| Earliest approval on file (Drugs@FDA) | March 11, 1968 | September 30, 1996 |
| First generic approved | August 14, 1986 | October 24, 2011 |
| Generic labelers (NDC) | 42 labelers | 43 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.119 per tablet (Carbamazepine 200 mg tablet) | $0.147 per tablet (Olanzapine 20 mg tablet) |
| 12-month price change | +0.6% | -5% |
| Boxed warning | Yes | Yes |
| Shortage now | A presentation being discontinued | No current entry |
| Recalls recorded | 11 | 14 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 66,615 | 107,881 |
| 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… eslicarbazepine, ethosuximide, everolimus, haloperidol, imatinib, itraconazole, lamotrigine, levothyroxine, methadone, methsuximide, mianserin, midazolam, olanzapine, oral and other hormonal contraceptives, oxcarbazepine, paliperidone, phensuximide, phenytoin, praziquantel, protease inhibitors, risperidone, sertraline, sirolimus, tadalafil, theophylline, tiagabine, topiramate, tramadol, trazodone, tricyclic …
Carbamazepine label, drug interactionsAcetazolamide, aprepitant, azole antifungals (e.g., ketoconazole, itraconazole, fluconazole, voriconazole), cimetidine, ciprofloxacin, clarithromycin, dalfopristin, danazol, dantrolene, delavirdine, diltiazem, erythromycin, fluoxetine, fluvoxamine, grapefruit juice, ibuprofen, isoniazid, loratadine, macrolides, nefazodone, niacinamide, nicotinamide, olanzapine, omeprazole, oxybutynin, protease inhibitors …
Olanzapine label, drug interactionsCarbamazepine: Increased clearance of olanzapine.
Olanzapine label, drug interactionsInducers of CYP1A2 – Carbamazepine therapy (200 mg bid) causes an approximately 50% increase in the clearance of olanzapine.
Source: FDA drug labels via openFDA
What next?
- Alternatives to carbamazepine
- every medicine labeled for the same conditions