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NaSSA Antidepressant Pregnancy: C

Mirtazapine (Elderly)

Brand names: Zispin SolTab, Mirtazapine

Adult dose

Dose: 15 mg once nightly initially; increase to 30–45 mg after 1–2 weeks
Route: oral
Frequency: once nightly
Max: 45 mg/day
Higher sedation at lower doses (H1 blockade predominates); less sedating at 30–45 mg; useful for depression with insomnia and weight loss

Paediatric dose

Route:
Not licensed for depression in children; limited evidence

Dose adjustments

Renal

Reduce dose in severe renal impairment

Hepatic

Reduce dose in hepatic impairment; avoid in severe

Clinical pearls

  • Paradox: 15 mg more sedating than 30 mg due to dominant H1 blockade at lower doses; NE enhancement at higher doses counteracts sedation
  • Excellent for elderly with poor appetite — weight gain is beneficial in malnourished patients
  • No sexual dysfunction, no QT prolongation, no anticholinergic side effects — good tolerability profile for elderly

Contraindications

  • Concurrent MAOIs
  • Mania

Side effects

  • Sedation/drowsiness
  • Weight gain (5HT2 and H1 blockade)
  • Dry mouth
  • Constipation
  • Increased appetite
  • Agranulocytosis (rare)
  • Hypertriglyceridaemia

Interactions

  • MAOIs (serotonin syndrome)
  • Alcohol/sedatives (enhanced CNS depression)
  • CYP3A4 inhibitors (increase levels)
  • Warfarin (may increase INR)

Monitoring

  • Weight
  • Lipids (long-term)
  • Agranulocytosis symptoms (sore throat, fever)
  • Mood assessment

Reference: BNFc; BNF 86; NICE NG222; BAP 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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