Luvox

(fluvoxamine)

Luvox (fluvoxamine); not controlled; brand discontinued, generic only

Summary

Luvox is a selective serotonin reuptake inhibitor whose only approved use is obsessive-compulsive disorder, indicated down to 8 years of age. The brand is discontinued, and the two generic forms are not interchangeable: the immediate-release tablet holds the pediatric indication, while the extended-release capsule has never been evaluated in children. Potent CYP1A2 inhibition gives it the largest interaction burden of any SSRI here. Not controlled; generic only.

Forms & Strengths

• Immediate-release tablets (pediatric-indicated, from 8 years): 25 mg, 50 mg, 100 mg
• Extended-release capsules (never evaluated in children, adults only): 100 mg, 150 mg
• No oral liquid or chewable form

Dosing

• Age:
  • Immediate-release tablets, OCD: 8 y/o and older, and adults
  • Extended-release capsules: adults only; never evaluated in pediatric patients
  • Not approved below 8 y/o, or for any indication other than OCD
• Onset: 1 to 2 weeks for early effect; 10 weeks for full response
• Duration: continuous with daily dosing; half-life 15.6 hours
• Initial Dose:
  • 8 to 17 y/o: 25 mg once daily at bedtime
  • Adults: 50 mg once daily at bedtime
• Titration:
  • 8 to 17 y/o: 25 mg every 4 to 7 days as tolerated
  • Adults: 50 mg every 4 to 7 days as tolerated
• Max Dose:
  • 8 to 11 y/o: 200 mg/day
  • 12 to 17 y/o: 300 mg/day, the adult maximum
  • Adults: 300 mg/day
• Considerations: These are immediate-release tablet doses; the extended-release capsule is not pediatric and starts at 100 mg. Split pediatric totals above 50 mg, adult totals above 100 mg, larger dose at bedtime. Titrate a girl more slowly than a boy.

Pharmacology

• Mechanism: potent serotonin reuptake inhibitor with no significant histaminergic, adrenergic, muscarinic or dopaminergic affinity
• Delivery / Release: immediate-release tablet; bioavailability 53%, unaffected by food; half-life 15.6 hours, shortest of the youth SSRIs
• Metabolism: hepatic to inactive metabolites; NONLINEAR kinetics over 100 to 300 mg/day. Clearance falls 30% in hepatic dysfunction, rises 25% in smokers.
• Class Positioning: enzyme inhibition, not receptor pharmacology, separates it from every other SSRI. A POTENT CYP1A2 inhibitor, it also inhibits CYP2C9, CYP3A4 and CYP2C19.
• Versus siblings: four outright drug contraindications no other SSRI carries

Indications

• Obsessive-compulsive disorder (ICD-10: F42.x): immediate-release tablets, 8 y/o and older, plus adults
• Obsessive-compulsive disorder, adults only (ICD-10: F42.x): extended-release capsules, never evaluated in children
• No other approved indication at any age; not approved for depression in the United States

Off-Label Uses

• Pediatric anxiety disorders (ICD-10: F93.0, F40.1, F41.1): CLASS-level support only; AHRQ graded SSRIs moderate to high. (AHRQ 2017)
• Depression in youth (ICD-10: F32.x, F33.x), autism repetitive behaviours (F84.0), ADHD (F90.x), and pediatric use of the extended-release capsule: all insufficient
• Choosing among pediatric OCD agents: AACAP makes CBT first line, adding medication for moderate to severe illness, with little evidence separating SSRIs. (AACAP 2011)

Contraindications & Warnings

• Boxed Warning: Suicidal thoughts and behaviors. Antidepressants increased this risk in children, adolescents and young adults. Observe closely for clinical worsening and suicidality, especially early and at dose changes; the label's stated interval is DAILY family observation with communication to the prescriber. Write the smallest quantity of tablets consistent with good patient management.
• Contraindicated:
  • Tizanidine: AUC rose about 33-fold, dropping systolic pressure a mean 35 mm Hg.
  • Thioridazine: concentrations triple, causing QTc prolongation, torsades and sudden death.
  • Alosetron: AUC rose 6-fold. Pimozide: QT prolongation and fatal torsades.
  • MAOIs, including linezolid and methylene blue: current use or within 14 days, either direction.
• Use with caution:
  • Known or suspected bipolar disorder; manic reactions hit 4% in the pediatric OCD trial.
  • Any seizure disorder; avoid in unstable epilepsy, stop if seizures increase.
  • Hyponatremia risk with diuretics; bleeding risk with aspirin, NSAIDs or anticoagulants; untreated narrow angles.
  • Hepatic impairment: lower the start, lengthen the interval.
  • Any narrow-window substrate: warfarin, theophylline, omeprazole, phenytoin.
• Screen before starting:
  • The medication list against CYP1A2, CYP3A4, CYP2C9 and CYP2C19 substrates; four agents are contraindicated.
  • Bipolar and seizure history, baseline suicidality, height and weight, and smoking status.
  • Confirmation the prescription reads immediate-release TABLETS, not capsules.

Drug Interactions

• Contraindicated: tizanidine, thioridazine, alosetron, pimozide, and MAOIs within 14 days. Choose another agent.
• Potent CYP1A2 inhibition is the defining hazard. Review the medication list for substrates before writing it and at every visit.
• Viloxazine (Qelbree): the likeliest collision in an ADHD practice; itself a strong CYP1A2 inhibitor, so combining stacks two potent inhibitors.
• Ramelteon AUC rose 190-fold; do not combine. Theophylline: cut to one third, monitor levels.
• Warfarin rose 98%; tricyclics, carbamazepine, clozapine, propranolol and methadone rise. Monitor levels; adjust methadone when fluvoxamine starts AND stops.
• Benzodiazepines: halve the alprazolam start, avoid diazepam; lorazepam and oxazepam are unaffected.
• Other serotonergic drugs (SNRIs, triptans, opioids, lithium, amphetamines): additive serotonin syndrome risk. Quitting smoking raises levels.

Administration

• Give at bedtime as one dose while the total is 50 mg or less in a child, 100 mg or less in an adult.
• Above those thresholds divide into two doses, the larger at bedtime. Give with or without food.
• Tablets must be swallowed; the 25 mg is unscored, thinly stocked.
• Never substitute extended-release capsules under 18: never evaluated in children, and its lowest strength, 100 mg, is four times the pediatric start.
• Titrate a girl more slowly than a boy the same age; girls reach benefit at lower doses.
• Missed dose: same day only, never doubled. Never stop abruptly.

Side Effects

• Common: nausea at about 40%, the commonest reason a child stops early, plus headache, somnolence, insomnia, dry mouth, nervousness, diarrhea and tremor; in children also emotional lability, hyperkinesia, ecchymosis and epistaxis
• Serious:
  • Suicidal thoughts and behavior: the boxed warning. Reassess early and at each dose change.
  • Serotonin syndrome: stop fluvoxamine and every serotonergic drug immediately.
  • Manic or hypomanic switch, 4% in the pediatric OCD trial: stop rather than titrating through.
  • Seizures, hyponatremia as SIADH, bleeding up to life-threatening haemorrhage.
  • Angle closure glaucoma, priapism, sexual dysfunction, weight loss. Ask directly and plot growth.

Monitoring & Labs

• Suicidality: daily family observation, plus clinician assessment of ideation and behaviour at every contact for 3 months and at every dose change.
• Medication reconciliation: recheck the full list at EVERY visit against CYP1A2, CYP3A4, CYP2C9 and CYP2C19 substrates. The highest-yield task.
• Activation and mania: ask during titration and every 3 months once stable about reduced sleep need, pressured speech and hyperactivity.
• Growth: height and weight charted at baseline, quarterly for a year, then twice yearly.
• Sodium, bleeding, seizures: check sodium for new headache or confusion; ask about bruising, nosebleeds and convulsions.
• Interacting-drug levels: check any narrow-window co-drug at baseline and 1 week post-change.
• Response: reassess with the same instrument at 10 weeks.

Discontinuation & Taper

• Do not stop abruptly; reduce gradually and monitor for discontinuation symptoms.
• Discontinuation syndrome: dysphoric mood, irritability, agitation, dizziness, electric shock sensations, headache, insomnia.
• Taper matters more here than for most SSRIs. Slow it as the dose gets small.
• If intolerable symptoms follow a decrease, resume the previous dose and go slower. Exception: emergent suicidality, where the label directs tapering as fast as feasible.
• Adjust methadone when fluvoxamine comes off. No drug holidays.

Pregnancy & Lactation

• Pregnancy: observational data show no clear risk of major birth defects or miscarriage. Risks: persistent pulmonary hypertension of the newborn, poor neonatal adaptation, a less than 2-fold rise in postpartum hemorrhage.
• Fertility: animal findings suggest impaired fertility on treatment. Weigh risk against relapse.
• Lactation: relative infant dose roughly 1%; maternal doses up to 300 mg daily are not expected to cause adverse effects, and not a reason to stop nursing. (LactMed 2026)
• Infant monitoring: watch for diarrhea, vomiting, poor sleep and agitation. (LactMed 2026)
• Exposure Registry: National Pregnancy Registry for Antidepressants, 1-844-405-6185, womensmentalhealth.org

Counseling Points

• Counsel the family on:

  • The tablet and the capsule not being the same medicine. If the pharmacy hands over capsules, call first.
  • Nausea being the commonest problem, worst in the first two weeks; food and slower titration, not stopping.
  • Bedtime dosing at 50 mg or less, splitting above that with the larger half at bedtime.
  • Bringing every new medicine to you first, over-the-counter included; this one changes how the body handles others.
  • Watching daily, early and after dose changes, for agitation, emotional swings or self-harm talk; never stopping abruptly; 10 weeks being the decision point.

• Advise them to call for:

  • New or worsening self-harm talk, or a sudden mood or behaviour change.
  • Several nights of almost no sleep, or pressured speech.
  • Agitation with fever, shivering, twitching or stiffness; same-day call.
  • Nosebleeds that will not stop, unusual bruising, or blood in vomit or stool.
  • Headache with confusion or unsteadiness, which can be low sodium.
  • A seizure, an erection over 4 hours, or sudden eye pain.

References

1. DailyMed. Fluvoxamine maleate tablets, ANI Pharmaceuticals; the pediatric-indicated IR product. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7ecd83ec-88f5-4f85-9cc2-9068375d8820
2. DailyMed. Fluvoxamine maleate extended-release capsules, Actavis Pharma; source of the never-evaluated-in-children statement. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8bbd7e39-b9ab-4716-9522-aa8c4b92210e
3. LactMed. Fluvoxamine. Drugs and Lactation Database, NICHD. https://www.ncbi.nlm.nih.gov/books/NBK501187/
4. AHRQ. Anxiety in Children. Comparative Effectiveness Review 192. https://www.ncbi.nlm.nih.gov/books/NBK476277/
5. AACAP. Practice Parameter for Obsessive-Compulsive Disorder in Youth. https://psychiatryonline.org/doi/10.1176/appi.focus.10.3.360
6. FDA. National Drug Code Directory, openFDA; generic name fluvoxamine. https://api.fda.gov/drug/ndc.json?search=generic_name:%22fluvoxamine%22&limit=1000