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Two medicines, side by side

Fluoxetine vs paroxetine

Fluoxetine and paroxetine are both labeled for depression and anxiety. Drugs@FDA records approvals of fluoxetine since 1987 and of paroxetine since 1992. Pharmacies paid $0.0519 per fluoxetine HCl 40 mg capsule and $0.0611 per paroxetine HCl 20 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. 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.”; Paroxetine, “The mechanism of action of paroxetine tablets in the treatment of MDD, SAD, OCD, PD, GAD, and PTSD is unknown, but is presumed to be linked to potentiation of serotonergic activity in the central …”

Check it at the source: the fluoxetine FDA label on DailyMed (effective January 8, 2026); the paroxetine FDA label on DailyMed (effective February 12, 2026).

Highlights of the fluoxetine record

Fluoxetine (Prozac) · label of January 8, 2026

Boxed warning

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: indications

PROZAC ® 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 paroxetine record

Paroxetine (Paxil) · label of February 12, 2026

Boxed warning

SUICIDAL THOUGHTS AND BEHAVIORS Antidepressants increased the risk of suicidal thoughts and behaviors in pediatric and young adult patients in short-term studies. Closely monitor all antidepressant-treated patients for clinical worsening, and for emergence of suicidal thoughts and behaviors [see Warnings and Precautions (5.1) ]. Paroxetine tablets are not approved for use in pediatric patients [see Use in Specific Populations (8.4) ].

Used for

From the label: indications

Paroxetine tablets are indicated in adults for the treatment of: • Major depressive disorder (MDD) • Obsessive compulsive disorder (OCD) • Panic disorder (PD) • Social anxiety disorder (SAD) • Generalized anxiety disorder (GAD) • Posttraumatic stress disorder (PTSD) Paroxetine tablets are a selective serotonin reuptake inhibitor (SSRI) indicated in adults for the treatment of ( 1 ): • Major Depressive Disorder (MDD) • Obsessive Compulsive Disorder (OCD) • Panic Disorder (PD) • Social Anxiety Disorder (SAD) • Generalized Anxiety Disorder (GAD) • Posttraumatic Stress Disorder (PTSD) […]

On the market

Earliest approval on file
December 29, 1992
Generic labelers
45 labelers
Pharmacy cost
$0.0611 per tablet

Supply and safety

Shortage
No current entry
Recalls
15

Source: FDA drug labels via openFDA (Fluoxetine label of January 8, 2026, Paroxetine label of February 12, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)

How do fluoxetine and paroxetine differ on the record?

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.”; Paroxetine, “The mechanism of action of paroxetine tablets in the treatment of MDD, SAD, OCD, PD, GAD, and PTSD is unknown, but is presumed to be linked to potentiation of serotonergic activity in the central …”

Both are in FDA's class serotonin reuptake inhibitors.

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.”; Paroxetine, “Elimination Metabolism The mean elimination half-life is approximately 21 hours (CV 32%) after oral dosing of 30 mg …”

Both labels carry a boxed warning; the records quote them.

Generics: fluoxetine since 2001; paroxetine since 2003 (Drugs@FDA).

FluoxetineParoxetine
Labeled forDepression, Anxiety, Bipolar disorderDepression, Anxiety, Menopause symptoms
Pharmacologic classSerotonin Reuptake InhibitorSerotonin Reuptake Inhibitor
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 paroxetine tablets in the treatment of MDD, SAD, OCD, PD, GAD, and PTSD is unknown, but is presumed to be linked to potentiation of serotonergic activity in the central nervous system resulting from inhibition of …
Half-life (label)Its mean terminal half-life after a single dose was 8.6 days and after multiple dosing was 9.3 days.Elimination Metabolism The mean elimination half-life is approximately 21 hours (CV 32%) after oral dosing of 30 mg tablets daily for 30 days of paroxetine tablets.
Earliest approval on file (Drugs@FDA)December 29, 1987December 29, 1992
First generic approvedAugust 2, 2001July 30, 2003
Generic labelers (NDC)58 labelers45 labelers
Pharmacy cost (NADAC, each one's most listed form; strengths differ)$0.0519 per capsule (Fluoxetine HCl 40 mg capsule)$0.0611 per tablet (Paroxetine HCl 20 mg tablet)
12-month price change-20%-16%
Boxed warningYesYes
Shortage nowNo current entryNo current entry
Recalls recorded915
FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used)131,82741,809
DEA schedulenonenone

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?

Paroxetine label, drug interactions

Use caution with concomitant use of BRISDELLE with other drugs that are metabolized by CYP2D6, including nortriptyline, amitriptyline, imipramine, desipramine, fluoxetine, phenothiazines, risperidone, and Type 1C antiarrhythmics (e.g., propafenone, flecainide, and encainide).

What both labels say about taking them together

Source: FDA drug labels via openFDA

What do the labels say about using others of their kind?

Fluoxetine label, warnings and precautions

Serotonin syndrome has been reported with SSRIs and SNRIs, including PROZAC, both when taken alone, but especially when co-administered with other serotonergic agents.

Paroxetine label, warnings and precautions

Increased risk when co-administered with other serotonergic agents, but also when taken alone.

Source: FDA drug labels via openFDA

What next?

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