SSRI Pregnancy: Should not be used during pregnancy unless the woman's clinical condition requires fluvoxamine. SSRI use in pregnancy, particularly late pregnancy, may increase the risk of persistent pulmonary hypertension of the newborn (about 5 per 1000 pregnancies vs 1-2 per 1000 background), and observational data indicate a less than 2-fold increased risk of postpartum haemorrhage with exposure within the month before birth. Neonatal withdrawal symptoms and third-trimester SSRI effects (feeding/respiratory difficulty, seizures, temperature instability, hypoglycaemia, tremor, irritability) have been described. Excreted in breast milk in small quantities - should not be used by women who breast feed. (SPC 4.6)

Fluvoxamine maleate

Brand names: Faverin

Fluvoxamine maleate is a selective serotonin reuptake inhibitor (SSRI) used for depression and obsessive-compulsive disorder.

Adult dose

Dose: Depression: 100 mg daily. Start on 50 mg or 100 mg as a single dose in the evening; review and adjust within 3 to 4 weeks of initiation

Route: Oral

Frequency: Once daily in the evening; doses up to 150 mg may be given as a single evening dose, but a total daily dose of more than 150 mg should be given in 2 or 3 divided doses

Max: 300 mg a day

Obsessive Compulsive Disorder (adults): recommended dose 100-300 mg daily, starting at 50 mg per day; if insufficient response after some weeks the dose may be increased gradually up to a maximum of 300 mg a day. Dosage adjustments should be made carefully on an individual basis to maintain the lowest effective dose. Depression should be treated for at least 6 months of symptom freedom; in OCD it is reasonable to consider continuation beyond 10 weeks in responders (long-term efficacy beyond 24 weeks not demonstrated) and the need for treatment reassessed periodically. Elderly: data give no indication of clinically significant differences in normal daily dosages, but upward titration should be slower and dosing always cautious (SPC 4.4). Paediatric: must NOT be used under 18 years for major depressive episode. For OCD in children over 8 years and adolescents there is limited data on a dose of up to 100 mg twice daily for 10 weeks - starting dose 25 mg per day, increased every 4-7 days in 25 mg increments as tolerated until an effective dose is achieved; the maximum dose in children should not exceed 200 mg/day; a total daily dose of more than 50 mg should be given in two divided doses, the larger dose at bedtime (not a per-kg regimen, so not entered as a structured paediatric dose). Withdrawal: avoid abrupt discontinuation - reduce the dose gradually over at least one to two weeks. Tablets should be swallowed with water without chewing. eMC SPC section 4.2.

Dose adjustments

Renal

Patients suffering from hepatic or renal insufficiency should start on a low dose and be carefully monitored (SPC 4.2).

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Combination with tizanidine
Combination with monoamine oxidase inhibitors (MAOIs) - start fluvoxamine two weeks after stopping an irreversible MAOI, or the day after stopping a reversible MAOI (e.g. moclobemide, linezolid); at least one week between stopping fluvoxamine and starting any MAOI
Combination with pimozide
Hypersensitivity to the active substance or to any of the excipients

Side effects

Nausea, sometimes with vomiting - the most frequently observed effect, usually diminishing within the first two weeks
Somnolence, insomnia, agitation, nervousness and anxiety
Headache, dizziness and tremor
Dry mouth, constipation, diarrhoea, dyspepsia and abdominal pain
Asthenia and malaise; hyperhidrosis
Hyponatraemia / SIADH, serotonin syndrome and convulsions (uncommon to rare)

Interactions

MAOIs (including moclobemide and linezolid) - contraindicated combination, washout periods required (SPC 4.3)
Tizanidine and pimozide - contraindicated combinations (SPC 4.3)
Fluvoxamine inhibits CYP1A2, CYP2C9, CYP3A4 and CYP2C19 - potential interaction with drugs metabolised by these isoenzymes (US label section 7.1)
Carbamazepine - elevated carbamazepine levels and symptoms of toxicity (US label 7.2)
Tricyclic antidepressants - significantly increased plasma TCA levels; monitor levels and reduce TCA dose if indicated (US label 7.2)
Propranolol or metoprolol - reduce dose and titrate more cautiously; diltiazem - bradycardia (US label 7.3)
Tacrine, sumatriptan and tryptophan - increased tacrine exposure with GI/autonomic symptoms; weakness, hyperreflexia and incoordination with sumatriptan; severe vomiting with tryptophan (US label 7.2)

Clinical monograph

How it works

It selectively inhibits presynaptic reuptake of serotonin, increasing serotonergic neurotransmission in the central nervous system.

Prescribing in practice

Fluvoxamine is a potent inhibitor of several cytochrome P450 enzymes (notably CYP1A2 and CYP2C19) and markedly raises levels of substrates such as theophylline, clozapine, tizanidine and agomelatine, so review interactions carefully and avoid contraindicated combinations.
Do not combine with monoamine oxidase inhibitors and observe the required washout, and avoid other serotonergic agents where possible because of serotonin syndrome risk.
Monitor for suicidal ideation early in treatment and in younger adults, and counsel on increased bleeding risk with antiplatelet or anticoagulant co-therapy.

Monitoring

Monitor mood and suicidality, response in obsessive-compulsive disorder, and for serotonergic, hyponatraemic or bleeding adverse effects, with vigilance for interacting drug levels.

Counselling the patient

Tell any prescriber you take fluvoxamine before starting new medicines, as it can raise levels of many drugs.
Report worsening mood or thoughts of self-harm, especially in the first weeks.
Do not stop abruptly; the dose should be reduced gradually.

Evidence & guidelines

Fluvoxamine is an established SSRI with a recognised role in obsessive-compulsive disorder supported by regulatory approval and NICE OCD guidance.

Reference: NICE CG31/CG90; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Pathways