Fluvoxamine
Brand names: Faverin
Fluvoxamine is a selective serotonin reuptake inhibitor (SSRI) used for depression and obsessive-compulsive disorder.
Adult dose
Dose adjustments
Patients suffering from hepatic or renal insufficiency should start on a low dose and be carefully monitored.
Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.
Contraindications
- Combination with tizanidine
- Combination with monoamine oxidase inhibitors (MAOIs) — fluvoxamine can be started two weeks after discontinuing an irreversible MAOI, or the day after discontinuing a reversible MAOI (e.g. moclobemide, linezolid); at least one week should elapse between stopping fluvoxamine and starting any MAOI
- Combination with pimozide
- Hypersensitivity to the active substance or to any of the excipients
Side effects
- Common: nausea (sometimes with vomiting — the most frequently observed symptom, usually diminishing within the first two weeks), abdominal pain, constipation, diarrhoea, dry mouth, dyspepsia
- Common: agitation, nervousness, anxiety, insomnia, somnolence, tremor, headache, dizziness
- Common: anorexia; hyperhidrosis/sweating; asthenia and malaise; palpitations/tachycardia; abnormal (delayed) ejaculation
- Uncommon: extrapyramidal disorder, ataxia, (orthostatic) hypotension, cutaneous hypersensitivity reactions (including angioneurotic oedema, rash, pruritus), abnormal hepatic function, arthralgia and myalgia
- Rare: convulsion, mania, hallucination, confusional state, aggression, hyponatraemia, photosensitivity reaction, galactorrhoea
- Frequency not known: serotonin syndrome, neuroleptic malignant syndrome-like events, suicidal ideation, SIADH, psychomotor restlessness/akathisia, haemorrhage (including gastrointestinal), bone fractures (SSRI class effect), drug withdrawal syndrome including neonatal withdrawal, Stevens-Johnson syndrome/toxic epidermal necrolysis
Interactions
- Tizanidine, MAOIs and pimozide — contraindicated combinations (UK SPC §4.3)
- Fluvoxamine inhibits several cytochrome P450 isoenzymes (CYP1A2, CYP2C9, CYP3A4 and CYP2C19), raising levels of their substrates (US label §7.1)
- Carbamazepine — elevated carbamazepine levels and symptoms of toxicity on co-administration (US label §7.2)
- Tricyclic antidepressants — significantly increased plasma TCA levels; use caution, monitor levels and reduce TCA dose if indicated. Tacrine — Cmax and AUC increased five- and eight-fold with nausea, vomiting, sweating and diarrhoea (US label §7.2)
- Benzodiazepines (co-administration with diazepam generally not advisable), clozapine (levels may rise, producing orthostatic hypotension or seizures) and methadone (may produce opioid intoxication) (US label §5.9)
- Propranolol or metoprolol — reduce dose and titrate more cautiously; diltiazem — bradycardia on co-administration; sumatriptan — rare reports of weakness, hyperreflexia and incoordination (US label §7.2, §7.3)
Clinical monograph
How it works
It selectively inhibits the presynaptic serotonin transporter, increasing synaptic serotonin availability.
Prescribing in practice
- There is an increased risk of suicidal thoughts and behaviour early in treatment, particularly in younger adults, requiring close monitoring.
- Fluvoxamine is a potent inhibitor of several cytochrome P450 enzymes, causing clinically important interactions including with theophylline, clozapine and tizanidine.
- Risk of hyponatraemia, gastrointestinal bleeding and serotonin syndrome rises with concomitant serotonergic drugs, NSAIDs or anticoagulants.
Monitoring
Monitor mood and suicidal ideation early in treatment and review for drug interactions and serotonergic adverse effects.
Counselling the patient
- Full benefit may take several weeks; continue as prescribed.
- Report worsening mood or thoughts of self-harm, especially early in treatment.
- Tell your prescriber about all other medicines because interactions are common; do not stop suddenly.
Evidence & guidelines
SSRIs including fluvoxamine are established first-line pharmacotherapy for depression and OCD in NICE guidance.
Reference: NICE CG31 (OCD); NICE CG90 (Depression); 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).
Related
Curated clinical cross-links plus same-class fallbacks.
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- Acute Behavioural Disturbance / Rapid Tranquillisation · RCEM 2022; RCPsych 2022; NICE NG10
- Self-Harm Presentation · NICE NG225 (2022)
- Capacity Assessment (Mental Capacity Act) · MCA 2005; Code of Practice
- Acute Psychosis Management · NICE CG178 2014
- Depression Management · NICE CG90 2022
- Lithium Therapy Monitoring · NICE CG185