Two medicines, side by side
Fluoxetine vs risperidone
Fluoxetine and risperidone are both labeled for bipolar disorder. Drugs@FDA records approvals of fluoxetine since 1987 and of risperidone since 1993. Pharmacies paid $0.0519 per fluoxetine HCl 40 mg capsule 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, fluoxetine is a serotonin reuptake inhibitor and risperidone an atypical antipsychotic.
Check it at the source: the fluoxetine FDA label on DailyMed (effective January 8, 2026); the risperidone FDA label on DailyMed (effective May 28, 2026).
Highlights of the fluoxetine record
Fluoxetine (Prozac) · label of January 8, 2026
SUICIDAL THOUGHTS AND BEHAVIORS Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term studies. These studies did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in patients over age 24; there was a reduction in risk with antidepressant use in patients aged 65 and older [see Warnings and Precautions ( 5.1 )].
Used for
From the label: indicationsPROZAC ® is indicated for the treatment of: Acute and maintenance treatment of Major Depressive Disorder [see Clinical Studies ( 14.1 )]. Acute and maintenance treatment of obsessions and compulsions in patients with Obsessive Compulsive Disorder (OCD) [see Clinical Studies ( 14.2 )]. […]
On the market
- Earliest approval on file
- December 29, 1987
- Generic labelers
- 58 labelers
- Pharmacy cost
- $0.0519 per capsule
Supply and safety
- Shortage
- No current entry
- Recalls
- 9
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 (Fluoxetine label of January 8, 2026, Risperidone label of May 28, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do fluoxetine and risperidone differ on the record?
In FDA's classes, fluoxetine is a serotonin reuptake inhibitor and risperidone an atypical antipsychotic.
How each works, in its label's words: Fluoxetine, “Although the exact mechanism of PROZAC is unknown, it is presumed to be linked to its inhibition of CNS neuronal uptake of serotonin.”; 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: Fluoxetine, “Its mean terminal half-life after a single dose was 8.6 days and after multiple dosing was 9.3 days.”; 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: fluoxetine since 2001; risperidone since 2008 (Drugs@FDA).
| Fluoxetine | Risperidone | |
|---|---|---|
| Labeled for | Depression, Anxiety, Bipolar disorder | Bipolar disorder, Schizophrenia |
| Pharmacologic class | Serotonin Reuptake Inhibitor | Atypical Antipsychotic |
| How it works (label) | Although the exact mechanism of PROZAC is unknown, it is presumed to be linked to its inhibition of CNS neuronal uptake of serotonin. | 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) | Its mean terminal half-life after a single dose was 8.6 days and after multiple dosing was 9.3 days. | 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) | December 29, 1987 | December 29, 1993 |
| First generic approved | August 2, 2001 | June 30, 2008 |
| Generic labelers (NDC) | 58 labelers | 37 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0519 per capsule (Fluoxetine HCl 40 mg capsule) | $0.0368 per tablet (Risperidone 0.25 mg tablet) |
| 12-month price change | -20% | -13% |
| Boxed warning | Yes | Yes |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 9 | 5 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 131,827 | 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?
Risperidone label, drug interactionsTitrate slowly. ( 7.1 ) Fluoxetine, paroxetine, and other CYP 2D6 enzyme inhibitors increase plasma concentrations of risperidone.
Risperidone label, drug interactionsAvoid alcohol. ( 7.1 ) Due to hypotensive effects, hypotensive effects of other drugs with this potential may be enhanced. ( 7.2 ) Effects of levodopa and dopamine agonists may be antagonized. ( 7.3 ) Cimetidine and ranitidine increase the bioavailability of risperidone. ( 7.5 ) Clozapine may decrease clearance of risperidone. ( 7.7 ) Fluoxetine and paroxetine increase plasma concentrations of risperidone. …
Source: FDA drug labels via openFDA
What do the labels say about using others of their kind?
Fluoxetine label, warnings and precautionsSerotonin syndrome has been reported with SSRIs and SNRIs, including PROZAC, both when taken alone, but especially when co-administered with other serotonergic agents.
Source: FDA drug labels via openFDA
What next?
- Alternatives to fluoxetine
- every medicine labeled for the same conditions