Míron (Mirtazapine)

Mirtazapine is a tetracyclic antidepressant that acts on serotonergic and noradrenergic pathways to improve mood and depressive symptoms.

• Major depressive disorder: reduces depressive symptoms and improves functional outcomes in adults.
• Depressive episodes in bipolar disorder: used as adjunctive therapy to manage the depressive phase.
• Treatment‑resistant depression: considered when first‑line antidepressants have not achieved adequate response.

• Mirtazapine antagonizes central presynaptic α2‑adrenergic receptors, increasing norepinephrine release, and blocks serotonin 5‑HT2 and 5‑HT3 receptors while also inhibiting histamine H1 receptors. This combined activity enhances noradrenergic and serotonergic neurotransmission, contributing to its antidepressant effects.

Mirtazapine may cause a range of adverse reactions, from mild to serious.

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 severe neutropenia
• Severe hypersensitivity reactions (e.g., Stevens‑Johnson syndrome)
• Suicidal thoughts or behavior, especially early in treatment
• Serotonin syndrome when combined with other serotonergic agents
• Hepatic dysfunction or jaundice
• Seizures in predisposed individuals

Before initiating therapy, clinicians should evaluate patient‑specific risk factors and monitor for adverse events.

• Hepatic function: assess liver enzymes in patients with hepatic impairment.
• Suicidal ideation: monitor closely during the first weeks of treatment.
• Elderly patients: use caution due to increased risk of sedation and falls.
• Discontinuation: avoid abrupt cessation to reduce withdrawal symptoms; taper as advised by prescriber.
• Concomitant CNS depressants: evaluate for additive sedation.
• Store at ambient temperature: keep in the original container, protect from moisture and direct sunlight.

Mirtazapine can interact with several drug classes, requiring careful management.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): risk of hypertensive crisis or serotonin syndrome.
• Other serotonergic agents (e.g., SSRIs, SNRIs, tramadol): increase serotonin syndrome risk.
• CNS depressants (e.g., benzodiazepines, alcohol): potentiate sedation and respiratory depression.
• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine): may raise mirtazapine plasma levels.
• Alcohol: enhances central nervous system depression.

Moderate Interactions (Monitor Closely)

• Antihypertensives: additive hypotensive effect.
• Anticholinergic drugs: may exacerbate anticholinergic burden.
• Carbamazepine: can reduce mirtazapine concentrations.
• Warfarin: potential alteration of INR; monitor coagulation.
• Lithium: increased risk of neurotoxicity; monitor serum levels.