Psychiatry/Noradrenergic/specific serotonergic (NaSSA)

Mirtazapine

also: NaSSA · alpha-2 antagonist

Overview

A noradrenergic and specific serotonergic antidepressant — its sedation and appetite stimulation make it useful for depression with insomnia or poor appetite.

Mechanism

Antagonises presynaptic α2-adrenoceptors → ↑noradrenaline and serotonin release; also blocks H1 (sedation) and 5-HT2/5-HT3 (↓nausea/sexual dysfunction).

Indications

Depression (esp. with insomnia / weight loss)

Adverse effects

Weight gain + increased appetiteclassic

Sedationclassic

More sedating at LOWER doses (H1 effect predominates).

Rare: agranulocytosisserious

Cautions & contraindications

Within 2 weeks of an MAOIall

Interactions

Additive sedation; serotonergics

Monitoring & kinetics

Weight; mood; FBC if infection symptoms

Oral nocte. Useful add-on with an SSRI/SNRI (different mechanism).

Choosing it

true

Source: BNF — Mirtazapine