Mirtazapine

Antidepressant · Presynaptic alpha-2-adrenoreceptor antagonist

Indications

Depressive illness.

Dosage

Adults: Initially 15 mg once daily at night. Titrate according to response, usually 15-45 mg as a single dose at night or in two equally divided doses morning and night. Withdraw gradually when symptom free 4-6 mth. Children: Not recommended.

Adverse Effects

Weight gain, increased appetite, abnormal dreams, confusion, anxiety, insomnia, drowsiness, headache, lethargy, dizziness, tremor, sedation, orthostatic hypotension, dry mouth, GI upset, rash, arthralgia, myalgia, back pain, peripheral oedema, fatigue. Reports of hyponatraemia, agranulocytosis.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Precautions: Hepatic or renal (CrCl, 40 mL/min) impairment, epilepsy, organic brain syndrome, diabetes, angina, cardiac conduction disturbances, recent MI, hypotension, prostatic hypertrophy, narrow- angle glaucoma or increased intraocular pressure. History of mania or psychosis. Monitor patients for suicidal ideation. Discontinue if jaundice occurs. Dose increases may be detrimental in patients who develop akathisia. Withdraw gradually. Elderly.

Interactions

MAOIs, SSRIs, SNRIs, tryptophan, triptans, tramadol, linezolid, lithium, St. John's Wort and other serotonergic agents. CNS depressants, alcohol, protease inhibitors, erythromycin, nefazodone, cimetidine, warfarin. Carbamazepine, phenytoin and other CYP3A4 inducers. Ketoconazole, other azole antifungals and other potent CYP3A4 inhibitors. Drugs that prolong QT interval.

Advice to Patient

Take with or without meals. Place disintegrating tablet on tongue and let it dissolve. Swallow without water. Take single daily dose at bedtime. Contact prescriber if there is agitation or confusion, chills, fever, mouth irritation, sore throat, muscle cramps, tremors, weakness, constant lack of sleep, change in gait, difficulty in breathing, chest pain, palpitations, fast heartbeat, change in vision, eye pain, change in urinary pattern, yellowing of eyes or skin, pale stools, dark urine or if there is worsening of condition. Avoid alcohol intake during therapy. Take sufficient amount of fluids (2-3 litres per day) to maintain hydration, unless restricted by the prescriber. Change position slowly from sitting or lying to standing.

Pharmacokinetics

Absorption: Rapid and complete. Metabolism: Extensively hepatic. Bioavailability: Approx. 50%. Half-life elimination: 20 to 40 hours; increased with renal or heapatic impairment. Time to peak, serum: Approx. 2 hours. Excretion: Urine (75%); feces (15%) as metabolites.

Brands with this active ingredient

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.