Mirtazapine Cf (Mirtazapine)

• Mirtazapine is a tetracyclic antidepressant used primarily in the management of depressive disorders.
• Major depressive disorder: reduces depressive symptoms and improves overall mood.
• Depressive episodes with comorbid anxiety: alleviates anxiety‑related symptoms while treating depression.
• Adjunct therapy for treatment‑resistant depression: may enhance response when combined with other antidepressants.

• Mirtazapine acts as an antagonist of central presynaptic α2‑adrenergic receptors, which increases the release of norepinephrine and serotonin. It also blocks 5‑HT2, 5‑HT3 and H1 histamine receptors, contributing to its antidepressant and sedative properties without directly stimulating serotonin reuptake.

Mirtazapine may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Sedation or drowsiness
• Increased appetite and weight gain
• Dry mouth
• Constipation
• Dizziness or light‑headedness
• Peripheral edema

Serious or Rare Side Effects

• Agranulocytosis or neutropenia
• Severe hypersensitivity reactions (e.g., Stevens‑Johnson syndrome)
• Suicidal thoughts or behavior, especially early in treatment
• Abnormal liver function tests
• Seizures in predisposed individuals
• Cardiac arrhythmias in patients with pre‑existing conditions

• Before initiating therapy, clinicians should consider several safety measures.
• Monitor weight: patients often experience increased appetite and weight gain.
• Assess suicidal risk: watch for emergent suicidal thoughts, particularly during the first weeks.
• Evaluate liver function: rare hepatic effects may occur.
• Avoid abrupt discontinuation: tapering reduces withdrawal symptoms.
• Caution in elderly: heightened sensitivity to sedation and orthostatic hypotension.
• Store at ambient temperature: keep in the original pack, protect from moisture.

Mirtazapine can interact with other medicines, requiring careful management.

Major Interactions (Avoid)

• MAO inhibitors: risk of hypertensive crisis; avoid concurrent use.
• CNS depressants (e.g., benzodiazepines, alcohol): additive sedation; avoid.
• Strong CYP2D6 inhibitors (e.g., fluoxetine): may raise mirtazapine levels; avoid.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., carbamazepine): may reduce efficacy; monitor response.
• Serotonergic agents (SSRIs, SNRIs, tramadol): potential serotonin syndrome; monitor.
• Anticholinergic drugs: additive anticholinergic effects; monitor for dry mouth and constipation.