SSRIs
also: sertraline · citalopram · fluoxetine · paroxetine · escitalopram
Overview
First-line antidepressants for depression and anxiety. The drug-choice rules (sertraline post-MI, fluoxetine in young people, citalopram QT) and the early-suicidality monitoring are core.
Mechanism
Selectively block the presynaptic serotonin transporter → ↑synaptic 5-HT. No significant antimuscarinic/anti-α1 effects (unlike TCAs) → safer in overdose.
Indications
- Depression (first-line)
- Generalised anxiety, panic, OCD (fluoxetine for OCD), PTSD
- Bulimia (fluoxetine)
The agents
Preferred post-MI / cardiac disease.
dose-dependent QT
Avoid in long-QT / with other QT drugs; caution elderly/hepatic.
First-line in children/adolescents; long t½ → less discontinuation, but slower to switch.
Worst discontinuation syndrome; avoid in pregnancy (cardiac defects).
Adverse effects
Review within 1 week in under-25s.
Add a PPI if also on NSAID/aspirin.
Especially elderly.
Flu-like, insomnia, nausea, imbalance, sensory, hyperarousal — taper; worst with paroxetine.
Cautions & contraindications
GI bleeding — add a PPI.
Serotonin syndrome.
Congenital heart defects.
Interactions
- Serotonergics (triptans, tramadol, MAOIs, St John's wort) → serotonin syndrome
- Warfarin/NSAID (bleeding); fluoxetine/paroxetine are CYP2D6 inhibitors
Monitoring & kinetics
Review at 1–2 weeks (sooner if <25); response at 4 weeks; Na⁺ in elderly; ECG (citalopram)
Oral; ~2–4 weeks to work. Continue ≥6 months after remission; taper to stop.
Source: NICE NG222 — Depression · BNF — SSRIs