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fluvoxamine

Adjunctive therapy

Brand: Luvox

Published 2025-09-28 · Last reviewed 2025-10-05 · 5 references

Content sourced from FDA labeling (DailyMed) and peer-reviewed literature.

Print sheet Review evidence

At a glance

Class: Adjunctive therapy·Typical dose: Adults (IR): typical start is 50 mg at bedtime; increase by 50 mg every 4–7 days based on response. Usual range 100–300 mg/day (divide doses above 150 mg/day).·Half-life: Single-dose mean 15 h; Steady-state mean 22 h·LAI available: No

Class: Adjunctive therapy
Typical dose: Adults (IR): typical start is 50 mg at bedtime; increase by 50 mg every 4–7 days based on response. Usual range 100–300 mg/day (divide doses above 150 mg/day).
Half-life: Single-dose mean 15 h; Steady-state mean 22 h
LAI available: No

Quick answers

What is fluvoxamine?: Fluvoxamine (brand Luvox) is a selective serotonin reuptake inhibitor approved for obsessive-compulsive disorder (1994) and social anxiety disorder (2008). It is frequently selected for OCD when psychotic disorders or clozapine therapy coexist, provided its interaction profile is managed carefully.
What is Luvox?: Luvox is a brand name for fluvoxamine.
What is Luvox (fluvoxamine) used for?: Label indications include: Obsessive-compulsive disorder; social anxiety disorder.
What drug class is Luvox (fluvoxamine)?: SSRI Antidepressant.
What is the mechanism of action of Luvox (fluvoxamine)?: Selective serotonin reuptake inhibitor (SSRI).
What strengths does Luvox (fluvoxamine) come in?: Immediate-release tablets: 25 mg, 50 mg, 100 mg.

General information

Fluvoxamine (brand Luvox) is a selective serotonin reuptake inhibitor approved for obsessive-compulsive disorder (1994) and social anxiety disorder (2008). It is frequently selected for OCD when psychotic disorders or clozapine therapy coexist, provided its interaction profile is managed carefully.

The drug is a strong CYP1A2 and CYP2C19 inhibitor, so it can markedly elevate concentrations of clozapine, olanzapine, theophylline, caffeine, and warfarin—useful when deliberate but hazardous without monitoring.

Immediate-release tablets (25 mg, 50 mg, 100 mg) and extended-release capsules (100 mg, 150 mg) allow once-nightly or divided dosing. IR tablets are widely generic; ER capsules remain largely branded. Bedtime dosing and food can mitigate nausea and somnolence.

The compare view and fluvoxamine evidence feed can support balancing activation and interaction trade-offs when titrating complex regimens.

Mania/hypomania screening can be coordinated via the bipolar disorder hub, and the schizophrenia hub can support clozapine collaboration; counseling guides can be shared via the fluvoxamine print page.

U.S. approvals

Obsessive-compulsive disorder (1994)
Social anxiety disorder (2008)

Formulations & strengths

Immediate-release tablets: 25 mg, 50 mg, 100 mg.
Extended-release capsules: 100 mg, 150 mg (do not crush or open).

Generic availability

IR tablets broadly available generically; ER capsules are predominantly brand-only in the U.S.

In complex regimens, fluvoxamine is sometimes used to raise clozapine levels; this approach typically involves dose reductions, therapeutic drug monitoring (TDM) when available, and counseling about caffeine or smoking changes that can shift exposure.

View labelExact

Mechanism of action

Refer to the Glossary entry on Neurotransmitters for background on receptor systems involved in serious mental illness.

Potent inhibition of the serotonin transporter with additional sigma-1 receptor agonism that may contribute to anxiolytic effects.

High-affinity SERT inhibitor.
Sigma-1 receptor agonist with minimal activity at histamine, adrenergic, or muscarinic receptors.

Metabolism & pharmacokinetics

Oral bioavailability ~53%; peak concentrations occur 3–8 hours post-dose for IR tablets.
Elimination half-life averages 15–26 hours, lengthening in older adults or hepatic impairment.
Extensive hepatic metabolism (CYP1A2 > CYP2D6/CYP2C19); fluvoxamine strongly inhibits CYP1A2/CYP2C19 and moderately inhibits CYP3A4/CYP2D6.
Steady state is achieved in roughly 10 days; ~94% of metabolites are excreted renally with <1% unchanged drug.

Dosing & administration

Adults (IR): typical start is 50 mg at bedtime; increase by 50 mg every 4–7 days based on response. Usual range 100–300 mg/day (divide doses above 150 mg/day).
Extended-release capsules: typical start is 100 mg nightly; titrate by 50 mg weekly to 300 mg/day for OCD (200 mg/day for SAD).
Pediatrics (≥8 years, IR): typical start is 25 mg at bedtime; titration is no faster than weekly to a maximum of 200 mg/day with divided dosing over 50 mg.
In hepatic impairment or geriatric patients, lower initial doses (often 25 mg daily) and slower titration are commonly used.
Taper over at least 1–2 weeks to minimize discontinuation symptoms.

Adverse effects

FDA boxed warnings

Like all antidepressants, fluvoxamine carries an increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults—closer monitoring is common during initiation and dose adjustments.

Common side effects (≥10%)

Nausea and dyspepsia: Most frequent adverse effect; bedtime dosing with a snack often helps.
Somnolence or fatigue: Larger dose is often given at night; divided dosing is considered if daytime sedation persists.
Activation/insomnia: Slower titration and morning dosing of smaller portions are often used to mitigate early activation.
Sweating and tremor: Usually dose-related; reassess if persistent.
Sexual dysfunction: Expectations and management options can be discussed upfront.

Other notable effects

Hyponatremia/SIADH, particularly in older adults or diuretic use; sodium checks are often obtained when symptoms occur.
Increased bleeding risk with NSAIDs, antiplatelets, or anticoagulants due to platelet aggregation inhibition.
Rare QTc prolongation; baseline ECG is often obtained when other risk factors are present.
Potential for mania/hypomania in bipolar spectrum disorders; screening is common prior to initiation.
Abrupt discontinuation can trigger dizziness, irritability, and sensory disturbances; gradual tapering is commonly used.

Interactions

Contraindicated with MAOIs (including linezolid or IV methylene blue); appropriate washouts are required (commonly 14 days).
Strong CYP1A2/CYP2C19 inhibition markedly raises levels of clozapine, olanzapine, theophylline, caffeine, tizanidine, and warfarin—dose reductions and monitoring of serum levels or clinical response are often needed.
Moderate inhibition of CYP3A4/CYP2D6 can elevate benzodiazepines, beta-blockers, and TCAs; dose adjustment and monitoring may be needed.
Combined serotonergic therapy (SSRIs/SNRIs, triptans, tramadol) increases serotonin syndrome risk—caution is common and symptom monitoring is important.
Changes in smoking status alter CYP1A2 activity; interacting drug levels are reassessed when smoking status changes.

Other useful information

Caffeine intake counseling is common; fluvoxamine can more than double caffeine exposure, worsening anxiety and insomnia.
Coordination with prescribers managing clozapine or theophylline is common, including serum monitoring when fluvoxamine is initiated or discontinued.
Weight, sleep quality, GI symptoms, and serum sodium are commonly monitored in higher-risk populations.

References

Related hubs:SMI toolkit·Support resources