Section 19 · Monograph
Mirtazapine
Reviewed Nov 2026FDA label
RemeronNoradrenergic and specific serotonergic antidepressant
- Forms
- Tab: 7.5, 15, 30, 45mg | ODT: 15, 30, 45mg
- Dose
- Depression with insomnia, anorexia or nausea: start 7.5-15mg at bedtime, up to 45mg/day
- MOA
- α2 antagonism with 5-HT2 and 5-HT3 and H1 blockade
Black Box Warning
- Increased risk of suicidal thoughts and behavior in children, adolescents and young adults (under 25) — monitor closely
Indications
- Major depressive disorderFDA-labeled
Off-Label Uses
- Depression with insomnia, anorexia and nausea in medical and palliative illnessOff-label
Mechanism of Action
- Alpha-2 adrenergic antagonist with 5-HT2, 5-HT3 and H1 receptor blockade, increasing noradrenergic and serotonergic transmission
Full Dosing
Adult / usual
- Start 7.5-15mg at bedtime; titrate to 15-45mg/day
- ODT form helps with swallowing difficulty
Renal
- Lower doses are often more sedating; reduce dose in renal or hepatic impairment and older adults
Contraindications
- MAO inhibitors within 14 days (and linezolid or IV methylene blue)
- Hypersensitivity
Drug Interactions
- Serotonergic drugs: serotonin syndrome
- Additive sedation with benzodiazepines, opioids and alcohol
- CYP3A4 inducers (carbamazepine, phenytoin) lower levels; inhibitors raise them
Adverse Effects
- Sedation, weight gain and increased appetite
- Dry mouth, constipation
- Agranulocytosis (rare)
- Hyponatremia, elevated lipids
- Serotonin syndrome
Monitoring Parameters
- Suicidality and mood
- Weight and lipids
- CBC if fever or infection signs
Pregnancy & Lactation
- Limited data; weigh benefit and risk
- Small amounts in milk