Mirtazapina Combino Pharm (Mirtazapine)

Mirtazapine is indicated for major depressive disorder, acting on the central nervous system to improve depressive symptoms in adult patients.

• Major depressive disorder: reduces depressive symptoms and improves mood in adults.
• Treatment‑resistant depression (off‑label): may be considered when first‑line agents are ineffective.
• Anxiety associated with depression (off‑label): can alleviate co‑existing anxiety symptoms.

• Mirtazapine antagonizes central presynaptic α2‑adrenergic receptors, which increases norepinephrine release, and blocks 5‑HT2 and 5‑HT3 receptors, enhancing serotonergic transmission while also antagonising H1 histamine receptors. This combined action leads to elevated norepinephrine and serotonin activity in the brain, contributing to its antidepressant effect.

Mirtazapine may cause a range of adverse reactions.

Common Side Effects

• Sedation or drowsiness: often most noticeable at treatment initiation.
• Increased appetite and weight gain: reported in many patients.
• Dry mouth: mild to moderate severity.
• Constipation: occasional gastrointestinal discomfort.

Serious or Rare Side Effects

• Agranulocytosis: severe reduction in white blood cells, requiring monitoring.
• Severe hypersensitivity reactions: including rash, angioedema, or anaphylaxis.
• Suicidal thoughts or behavior: especially in early treatment phases.
• Hepatic dysfunction: rare elevation of liver enzymes.

Before initiating therapy, consider the following precautions.

• Cardiovascular disease: monitor blood pressure and heart rate.
• Liver impairment: dose adjustment may be required.
• Renal impairment: assess renal function for appropriate dosing.
• Concomitant CNS depressants: increased risk of sedation.
• Pregnancy and lactation: use only if benefits outweigh potential risks.
• Store at ambient temperature: keep below 25°C, retain in original packaging, and protect from moisture.

Mirtazapine can interact with several drug classes.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): risk of serotonin syndrome; a washout period is required.
• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine): may increase mirtazapine plasma levels.
• CNS depressants (e.g., benzodiazepines, alcohol): can potentiate sedation and respiratory depression.

Moderate Interactions (Monitor Closely)

• Anticholinergic agents: may exacerbate dry mouth and constipation.
• Warfarin: occasional reports of altered INR; monitor coagulation parameters.
• Other serotonergic agents: monitor for additive serotonergic effects.