Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
Antidepressant selection and early monitoring
Psychiatry · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Severe early adverse reaction
Serotonin toxicity, mania, severe agitation or akathisia, collapse, dangerous hyponatraemia, major bleeding, arrhythmia or emergent suicidal intent requires urgent assessment rather than routine titration.
Action: Assess ABCDE, observations, ECG and relevant blood tests, stop or withhold suspected treatment when clinically required, manage the syndrome and seek urgent toxicology, medical or psychiatric advice. Secure immediate safety and document all interacting medicines and recent dose changes.
Synopsis
Choose an antidepressant from individual benefits, harms, overdose safety, interactions, comorbidity and preference, prescribe a usable regimen and monitor early suicidality, activation, withdrawal and physical adverse effects at guideline-aligned intervals.
Before prescribing, confirm indication and severity, previous response, bipolar history, suicide and overdose risk, pregnancy, physical illness, substances and all interacting medicines.
SSRIs are commonly considered because of tolerability and relative overdose safety, but choose within and beyond the class according to the person's priorities.
Discuss nausea, sleep and sexual effects, bleeding, hyponatraemia, activation, emotional blunting, driving impairment, discontinuation symptoms and expected onset.
Sertraline adult depression treatment starts at 50 mg once daily and can increase by 50 mg no more frequently than weekly to 200 mg daily when indicated.
Citalopram adult depression usually starts at 20 mg once daily; the maximum is 40 mg daily, reduced to 20 mg in older adults and hepatic impairment because of QT risk.
Mirtazapine is taken once daily at night, commonly starting 15 to 30 mg and adjusted within 15 to 45 mg daily, with sedation and weight gain discussed.
Review within two weeks, or within one week for age 18 to 25 or particular suicide concern, and repeat as frequently as clinical need requires.
Assess adherence, early harms, suicidality, mania, akathisia and function before increasing; benefit usually becomes evident within about four weeks when effective.
Continue effective treatment for at least six months after remission and use staged tapering rather than alternate-day dosing or abrupt cessation when stopping.
Key red flags
New reduced sleep need, increased activity, grandiosity or risky behaviour after an antidepressant suggests mania or hypomania and requires prompt bipolar review.
Marked inner restlessness and inability to remain still may be akathisia, which can intensify distress and suicide risk and should not be dismissed as anxiety.
Confusion, headache, seizure or falls after initiation may indicate hyponatraemia, especially in older people or those taking diuretics.
Citalopram and escitalopram have dose-dependent QT effects and require attention to cardiac disease, electrolytes, interacting QT medicines and current maximum doses.
Tricyclic antidepressants and venlafaxine can be more dangerous in overdose than many SSRIs, making medication quantity and access clinically important in self-harm risk.
Antidepressant treatment is an informed preferred option.
Review bipolarity, suicide and overdose risk, previous treatment, pregnancy, physical illness, substances and interactions.
Compare likely benefit, common and serious harms, withdrawal, dosing and monitoring with the person's priorities.
Choose a single clear regimen, provide written safety advice and arrange limited supply or support when overdose access is relevant.
Key medicines
SertralineStart 50 mg orally once daily for adult depression; increase by 50 mg steps at intervals of at least one week when needed, to no more than 200 mg daily.Avoid with MAOIs and review serotonergic combinations; monitor activation, bleeding, sodium, sexual dysfunction and hepatic factors, and consider pregnancy and breastfeeding guidance individually.
CitalopramStart 20 mg orally once daily in adults; maximum 40 mg daily, but use no more than 20 mg daily in adults over 65 or with hepatic impairment.Dose-dependent QT prolongation requires review of cardiac disease, bradycardia, electrolytes and QT-prolonging medicines; avoid with known QT prolongation and follow current MHRA contraindications.
Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.