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SSRI (Selective Serotonin Reuptake Inhibitor) — OCD Specialist Pregnancy: Should not be used during pregnancy unless the clinical condition of the woman requires treatment with fluvoxamine. SSRI use in pregnancy, particularly in late pregnancy, may increase the risk of persistent pulmonary hypertension of the newborn (about 5 cases per 1000 pregnancies vs 1–2 per 1000 in the general population); observational data indicate an increased risk (less than 2-fold) of postpartum haemorrhage following SSRI/SNRI exposure within the month before birth. Isolated cases of neonatal withdrawal symptoms have been described after use at the end of pregnancy, and third-trimester SSRI exposure has been associated with feeding and/or respiratory difficulties, seizures, temperature instability, hypoglycaemia, tremor, abnormal muscle tone, jitteriness, cyanosis, irritability, lethargy, somnolence, vomiting, difficulty sleeping and constant crying, sometimes requiring prolonged hospitalisation. Breast-feeding: fluvoxamine is excreted in human milk in small quantities and the drug should not be used by women who breast feed. Fertility: animal studies show impaired male and female fertility; fluvoxamine should not be used in patients attempting to conceive unless their clinical condition requires it.

Fluvoxamine

Brand names: Faverin

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

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Depression (adults): recommended dose 100 mg daily; start on 50 mg or 100 mg as a single dose in the evening. Obsessive compulsive disorder (adults): recommended dose 100–300 mg daily; start at 50 mg per day
Route: Oral
Frequency: Doses up to 150 mg can be given as a single dose, preferably in the evening; a total daily dose of more than 150 mg should be given in 2 or 3 divided doses
Max: 300 mg a day
Source: UK SPC (eMC) for Faverin 100 mg Film-coated Tablets, §4.2 (https://www.medicines.org.uk/emc/product/6603/smpc). DEPRESSION: dosage should be reviewed and adjusted if necessary within 3 to 4 weeks of initiation and thereafter as judged clinically appropriate; although there may be an increased potential for undesirable effects at higher doses, if after some weeks on the recommended dose the response is insufficient some patients may benefit from a gradual increase up to a maximum of 300 mg a day. Patients with depression should be treated for a sufficient period of at least 6 months to ensure that they are free from symptoms. OCD: if a good therapeutic response is obtained, treatment can be continued at an individually adjusted dosage; OCD is a chronic condition and it is reasonable to consider continuation beyond 10 weeks in responding patients; long-term efficacy (more than 24 weeks) has not been demonstrated in OCD; the need for treatment should be reassessed periodically. In both indications, dosage adjustments should be made carefully on an individual patient basis to maintain patients at the lowest effective dose. DISCONTINUATION: abrupt discontinuation should be avoided — reduce the dose gradually over a period of at least one or two weeks to reduce the risk of withdrawal reactions; if intolerable symptoms occur after a dose decrease or on discontinuation, resuming the previously prescribed dose may be considered, then decreasing more gradually. ELDERLY (§4.4): no indication of clinically significant differences in normal daily dosages compared with younger subjects, but upward dose titration should be done more slowly and dosing should always be done with caution. PAEDIATRIC (not a per-kg dose, so not expressed as mg/kg — verify any under-18 use against a children's formulary): fluvoxamine should NOT be used in children and adolescents under 18 years for major depressive episode (efficacy and safety not established). For OCD in children over 8 years and adolescents there is limited data on a dose of up to 100 mg b.i.d. for 10 weeks: the starting dose is 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, and if the two divided doses are not equal the larger dose should be given at bedtime. METHOD OF ADMINISTRATION: tablets should be swallowed with water and without chewing. §4.4 was truncated at the source-fetch limit and §4.5 was not retrieved in this bundle — verify the complete interactions section (interactions listed below are from §4.3 of the UK SPC and the US label's drug-interaction summary, as marked).

Dose adjustments

Renal

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.