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Mirtazapine Dosage

Medically reviewed by Last updated on Jan 3, 2022.

Applies to the following strengths: 15 mg; 30 mg; 45 mg; 7.5 mg

Usual Adult Dose for Depression

Initial dose: 15 mg orally once a day at bedtime
Maintenance dose: 15 to 45 mg orally once a day
Maximum dose: 45 mg/day


  • May increase the dose every 1 to 2 weeks to a maximum 45 mg/day according to patient response.
  • Patients should be periodically reassessed to determine the need for continued use of this drug.

Use: Treatment of major depressive disorder

Renal Dose Adjustments

Moderate to severe renal impairment (CrCl less than 40 mL/min): Use with caution

Liver Dose Adjustments

Use with caution.

Dose Adjustments

Switching from:

  • MAOI to this drug: At least 14 days should elapse
  • This drug to MAOI therapy: At least 14 days should elapse
  • Immediate treatment with linezolid or IV methylene blue: Stop this drug during treatment and resume after the last dose of linezolid or methylene blue

Treatment withdrawal:
  • A gradual dose reduction is recommended instead of abrupt cessation when possible.
  • If intolerable symptoms occur, consider resuming the previously prescribed dose and decreasing the dose at a more gradual rate.



  • SUICIDALITY AND ANTIDEPRESSANT DRUGS: Increased risk of suicidal thinking and behavior has been observed in children, adolescents, and young adults less than 24 years old. Patients should be monitored and closely observed for clinical worsening, suicidality, or unusual changes in behavior. Caregivers and family members should be advised of the need for close observation and communication with the healthcare provider.

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.


Data not available

Other Comments

Administration advice:

  • Oral disintegrating tablets: Open blister pack with dry hands and place tablet on tongue; may be taken with or without water
  • Oral tablets: Do not chew; may be taken with or without food

Storage requirements:
  • See manufacturer product information.

  • When switching between the oral solution and tablet formulations, care should be taken as slight pharmacokinetic differences may exist.
  • This drug may be taken in two divided doses, with the higher dose taken at night.
  • Use should ideally continue for 4 to 6 months after patients are completely symptom-free.

  • For signs/symptoms of suicidality or unusual behavior, especially during initiation and dose titrations
  • For symptoms of serotonin syndrome, particularly when given with other serotonergic agents
  • For symptoms associated with withdrawal, especially with discontinuation or dose titration
  • For signs/symptoms of agranulocytosis

Patient advice:
  • Advise patients, and families/caregivers to monitor and report signs/symptoms of suicidality, and/or unusual behavior immediately to their healthcare provider (e.g., agitation, irritability, anxiety, panic attacks, insomnia, hostility, aggressiveness, impulsivity, akathisia, hypomania/mania).
  • Advise patients to report signs/symptoms of agranulocytosis.
  • Inform patients that this drug may cause drowsiness, and they should avoid driving or operating machinery until the full effects of the drug are seen.
  • Tell patients that this drug may take 1 to 4 weeks until clinical improvement is observed; patients should be warned to avoid abrupt discontinuation of this drug.
  • Advise patients to speak to their healthcare provider if they become pregnant, intend to become pregnant, or are breastfeeding.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.