Fluoxetine

ATC code

N06AB03

Therapeutic class

Antidepressant (Selective serotonin reuptake inhibitor) · Selective serotonin reuptake inhibitor

Forms

oral capsule, oral tablet, oral solution

Brand names

Prozac (US) · Fluoxetina Cinfa (ES) · Sarafem (US)

Overall confidence

medium

Regulatory sources consulted

aemps-cima-ft-63499
crediblemeds.org
flockhart-table-2024
professional-knowledge
RxNorm rxcui 4493 ↗

Approved indications

Major depressive episodes.
Obsessive-compulsive disorder.
Bulimia nervosa: as a complement to psychotherapy for the reduction of binge-eating and purging behaviors.

Contraindications

Absolute

Hypersensitivity to the active substance or to any of the excipients.
Concomitant use with irreversible, non-selective monoamine oxidase inhibitors (MAOIs). A washout period of at least 5 weeks is required.
Concomitant use with metoprolol used in heart failure.

Clinical warnings

Boxed warning · Increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults (under 25 years old). — FDA
Major warning · Risk of serotonin syndrome, especially with concomitant use of other serotonergic agents. Requires monitoring and possible discontinuation of treatment. — AEMPS CIMA
QT interval prolongation and ventricular arrhythmias, including Torsades de Pointes. Use with caution in patients with risk factors. — AEMPS CIMA

Drug interactions

HighMonoamine Oxidase Inhibitors (MAOIs)N06AF
Mechanism: Synergistic increase in serotonin levels, with high risk of life-threatening serotonin syndrome.
Recommendation: Contraindicated. Allow a washout period of at least 14 days after stopping an MAOI before starting fluoxetine, and at least 5 weeks after stopping fluoxetine before starting an MAOI.
AEMPS CIMA
HighTamoxifenL02BA01
Mechanism: Fluoxetine, a potent CYP2D6 inhibitor, blocks the conversion of tamoxifen to its active metabolite, endoxifen, significantly reducing its antineoplastic efficacy.
Recommendation: Avoid concomitant use. If an antidepressant is required, choose one with minimal or no CYP2D6 inhibition (e.g., citalopram, escitalopram, venlafaxine).
PMID:19726629
ModerateQT-prolonging drugs
Mechanism: Additive effect on QT interval prolongation, increasing the risk of serious ventricular arrhythmias such as Torsades de Pointes.
Recommendation: Avoid concomitant use if possible, especially with Class IA and III antiarrhythmics, some antipsychotics, and antibiotics. If necessary, monitor ECG.
CredibleMeds.org

Adverse events

Common (≥1%)

insomnia · headache · diarrhea · nausea · fatigue · decreased appetite · anxiety

Rare but serious

serotonin syndrome · QT prolongation · Torsades de Pointes · hyponatremia · suicidal ideation · seizures · anaphylactic reaction

Pregnancy and lactation

FDA category: D

Should not be used during pregnancy unless the clinical condition of the woman requires it. Third-trimester exposure may increase the risk of persistent pulmonary hypertension of the newborn (PPHN). It is excreted in human milk and may cause adverse effects in the nursing infant.