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Serotonin-Noradrenaline Reuptake Inhibitor (SNRI) Pregnancy: Avoid if possible — neonatal withdrawal syndrome (SSRI discontinuation syndrome-like), pulmonary hypertension (theoretical)

Venlafaxine

Brand names: Efexor XL

Adult dose

Dose: Starting: 37.5–75 mg OD (XL). Increase by 75 mg every 4 weeks as needed. Target: 75–225 mg OD.
Route: Oral (XL capsule — swallow whole)
Frequency: Once daily (XL formulation)
Max: 225 mg/day (depression); 75–225 mg/day (GAD/anxiety)
Higher doses (≥150 mg) have noradrenergic effects. Blood pressure: dose-dependent BP increase. XL capsules must not be opened/crushed. Discontinuation syndrome significant — taper slowly.

Paediatric dose

Route: N/A
Frequency: N/A
Max: Not licensed in children/adolescents
Black box warning in US: increased suicidality in adolescents with depression — not licensed for paediatric use

Dose adjustments

Renal

Reduce daily dose by 25–50% if eGFR <10

Hepatic

Reduce dose by 50% in hepatic impairment

Clinical pearls

  • Discontinuation syndrome: among worst of all antidepressants — taper very slowly (reduce by 37.5 mg every 4 weeks minimum; lower reductions if needed)
  • Blood pressure: check at baseline and every 3–6 months — dose-dependent rise; discontinue if sustained BP rise
  • Nausea: usually resolves after 1–2 weeks — advise patients to persist
  • More effective than SSRIs at higher doses due to added noradrenergic mechanism

Contraindications

  • MAOIs (within 14 days)
  • Severe hepatic impairment
  • Uncontrolled hypertension

Side effects

  • Nausea (first 2 weeks)
  • Sweating
  • Dry mouth
  • Insomnia
  • Hypertension (dose-dependent — monitor BP)
  • Tachycardia
  • Sexual dysfunction
  • Discontinuation syndrome (severe — dizziness, electric shock sensations, crying spells)

Interactions

  • MAOIs — serotonin syndrome (absolutely contraindicated)
  • Tramadol/triptans — serotonin syndrome risk
  • Antihypertensives — reduced effect and BP rise
  • Warfarin — may affect INR

Monitoring

  • Blood pressure (baseline and periodic)
  • ECG (QTc)
  • Suicidality (especially early treatment)
  • Discontinuation plan before stopping

Reference: BNFc; BNF; NICE NG222 Depression; BAP Antidepressant Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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