Mirtazapine

The mechanism of action of mirtazapine for the treatment of major depressive disorder, is unclear. However, its efficacy could be mediated through its activity as an antagonist at central presynaptic α 2 -adrenergic inhibitory autoreceptors and heteroreceptors and enhancing central noradrenergic and serotonergic activity.

• Mirtazapine tablets are indicated for the treatment of major depressive disorder (MDD) in adults [see Clinical Studies (14) ]. Mirtazapine tablets are indicated for the treatment of major depressive disorder (MDD) in adults.ICD-10: F32.9

• Mirtazapine tablets are contraindicated in patients: • Taking, or within 14 days of stopping, MAOIs (including the MAOIs linezolid and intravenous methylene blue) because of an increased risk of serotonin syndrome [see Warnings and Precautions (5.3) , Drug Interactions (7) ]. • With a known hypersensitivity to mirtazapine or to any of the excipients in mirtazapine tablets.contraindicated

• Starting dose: 15 mg once daily; may increase up to maximum recommended dose of 45 mg once daily. ( 2.1 ) • Administer orally once daily, preferably in the evening prior to sleep. ( 2.1 ) • Reduce dose gradually when discontinuing mirtazapine tablets. ( 2.6 , 5.13 ) 2.1 Recommended Dosage The recommended starting dose of mirtazapine tablets is 15 mg once daily, administered orally, preferably in the evening prior to sleep. If patients do not have an adequate response to the initial 15 mg dose, increase the dose up to a maximum of 45 mg per day. Dose changes should not be made in intervals of less than 1 to 2 weeks to allow sufficient time for evaluation of response to a given dose [see Clinical Pharmacology (12.3) ]. 2.3 Screen for Bipolar Disorder Prior to Starting Mirtazapine Tablets Prior to initiating treatment with mirtazapine tablets or another antidepressant, screen patients for a personal or family history of bipolar disorder, mania, or hypomania [see Warnings and Precautions (5.8) ]. 2.4 Switching Patients to or from a Monoamine Oxidase Inhibitor Antidepressant At least 14 days must elapse between discontinuation of a monoamine oxidase inhibitor (MAOI) antidepressant and initiation of mirtazapine tablets. In addition, at least 14 days must elapse after stopping mirtazapine tablets before starting an MAOI antidepressant [see Contraindications (4) and Warnings and Precautions (5.3) ].

• Agranulocytosis: If sore throat, fever, stomatitis or signs of infection occur, along with a low white blood cell count, treatment with mirtazapine should be discontinued and the patient should be closely monitored. ( 5.2 ) • Serotonin Syndrome: Increased risk when co-administered with other serotonergic drugs (e.g., SSRI, SNRI, triptans), but also when taken alone. If it occurs, discontinue mirtazapine and initiate supportive treatment. ( 2.4 , 4 , 5.3 , 7 ) • Angle-Closure Glaucoma: Angle closure glaucoma has occurred in patients with untreated anatomically narrow angles treated with antidepressants. ( 5.4 ) • QTc Prolongation: Use mirtazapine with caution in patients with risk factors for QTc prolongation. ( 5.5 , 7 ) • Increased Appetite/Weight Gain: mirtazapine has been associated with increased appetite and weight gain. ( 5.6 ) • Somnolence: May impair judgment, thinking and/or motor skills. Use with caution when engaging in activities requiring alertness, such as driving or operating machinery. ( 5.7 , 7 ) • Activation of Mania/Hypomania: Screen patients for bipolar disorder prior to initiating treatment. ( 2.3 , 5.8 ) • Seizures: Use with caution in patients with a seizure disorder. ( 5.9 ) • Elevated Cholesterol/Triglycerides: Has been reported with mirtazapine use. ( 5.10 ) • Hyponatremia: May occur as a result of treatment with serotonergic antidepressants, including mirtazapine. ( 5.11 ) • Transaminase Elevations: Clinically significant elevations have occurred. Use with caution in patients with impaired hepatic function.

The following adverse reactions are described in more detail in other sections of the prescribing information: • Hypersensitivity [see Contraindications (4) ] • Suicidal Thoughts and Behaviors [see Warnings and Precautions (5.1) ] • Agranulocytosis [see Warnings and Precautions (5.2) ] • Serotonin Syndrome [see Contraindications (4) , Warnings and Precautions (5.3) , Drug Interactions (7) ] • Angle-Closure Glaucoma [see Warnings and Precautions (5.4) ] • QT Prolongation and Torsades de Pointes [see Warnings and Precautions (5.5) ] • Increased Appetite and Weight Gain [see Warnings and Precautions (5.6) ] • Somnolence [see Warnings and Precautions (5.7) ] • Activation of Mania or Hypomania [see Warnings and Precautions (5.8) ] • Seizures [see Warnings and Precautions (5.9) ] • Elevated Cholesterol and Triglycerides [see Warnings and Precautions (5.10) ] • Hyponatremia [see Warnings and Precautions (5.11) ] • Transaminase Elevations [see Warnings and Precautions (5.12) ] • Discontinuation Syndrome [see Warnings and Precautions (5.13) ] • Use in Patients with Concomitant Illness [see Warnings and Precautions (5.14) ] Most common adverse reactions (≥5% or greater and twice placebo) were somnolence, increased appetite, weight gain, and dizziness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Rising Health, LLC at 1-833-395-6928 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

• Pregnancy : Use only if clearly needed. ( 8.1 ) • Nursing Mothers: Caution should be exercised when administered to a nursing woman. ( 8.3 ) • Geriatric Use : Use with caution in elderly patients. ( 5.11 , 5.14 , 8.5 ) • Renal impairment: Dosage decrease may be needed in patients with moderate to severe renal impairment. ( 8.6 ) • Hepatic impairment : Dosage decrease may be needed in patients with hepatic impairment. ( 8.6 ) 8.1 Pregnancy Reproduction studies in pregnant rats and rabbits at doses up to 100 mg/kg and 40 mg/kg, respectively [20 and 17 times the maximum recommended human dose (MRHD) on an mg/m 2 basis, respectively], have revealed no evidence of teratogenic effects. However, in rats, there was an increase in post-implantation losses in dams treated with mirtazapine. There was an increase in pup deaths during the first 3 days of lactation and a decrease in pup birth weights. The cause of these deaths is not known. The effects occurred at doses that were 20 times the MRHD, but not at 3 times the MRHD, on an mg/m 2 basis. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, mirtazapine should be used during pregnancy only if clearly needed. 8.3 Nursing Mothers Mirtazapine may be excreted in breast milk. Exercise caution when administering mirtazapine to nursing women.

Metabolism

Plasma levels of mirtazapine are linearly related to dose over a dose range of 15 to 80 mg (1.78 times the maximum recommended dose). Steady state plasma levels of mirtazapine are attained within 5 days, with about 50% accumulation (accumulation ratio=1.5).

Human Experience In premarketing clinical studies, there were reports of mirtazapine overdose alone or in combination with other pharmacological agents. Signs and symptoms reported in association with overdose included disorientation, drowsiness, impaired memory, and tachycardia. Based on postmarketing reports, serious outcomes (including fatalities) may occur at dosages higher than the recommended doses, especially with mixed overdoses. In these cases, QT prolongation and Torsades de Pointes have also been reported [see Warnings and Precautions (5.5) , Adverse Reactions (6.2) , and Drug Interactions (7) ]. Overdose Management No specific antidotes for mirtazapine are known. Contact Poison Control (1-800-222-1222) for the latest recommendations.

• Jun 14, 1996NDANDA020415Organon
• Jan 12, 2001NDANDA021208Organon Usa Organon
• Jun 19, 2003ANDAANDA076122Mylan
• Apr 22, 2004ANDAANDA076541Sun Pharm Inds Inc
• Oct 22, 2004ANDAANDA076921Aurobindo
• Dec 8, 2005ANDAANDA077376Aurobindo Pharma
• Aug 22, 2007ANDAANDA077666Apotex
• Jun 1, 2017ANDAANDA205798Square Pharms Plc

1. 1Nausea4,9395.5%
2. 2Fatigue4,8015.4%
3. 3Drug Ineffective4,6875.2%
4. 4Fall4,0964.6%
5. 5Diarrhoea4,0424.5%
6. 6Off Label Use3,9064.4%
7. 7Toxicity To Various Agents3,7574.2%
8. 8Anxiety3,5203.9%
9. 9Dizziness3,4873.9%
10. 10Dyspnoea3,4523.9%
11. 11Death3,3843.8%
12. 12Drug Interaction3,2823.7%
13. 13Vomiting3,2703.7%
14. 14Depression3,2483.6%
15. 15Headache3,0983.5%

Recent PubMed references pinned to Mirtazapine as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Optimizing Mirtazapine Initial Dosing: A Population Analysis of the Effects of BMI, Paroxetine and Fluvoxamine.
  Drug design, development and therapy · 2026 · Yan H, Huang W, Xia H, et al.
  PMID 42261444DOI 10.2147/DDDT.S601238
• Mirtazapine alleviates depressive-like behaviors through the paraventricular SIK1-CRTC1 signaling pathway.
  Journal of affective disorders · 2026 · Zhang H, Dong H, Xi Z, et al.
  PMID 42184937DOI 10.1016/j.jad.2026.122021
• Overcoming mirtazapine's therapeutic limitations in veterinary practice: Development of a taste - masked orally disintegrating tablet with microsphere-based controlled release.
  Veterinary journal (London, England : 1997) · 2026 · Lu Y, Guo Y, Ma W, et al.
  PMID 42142869DOI 10.1016/j.tvjl.2026.106703
• Mirtazapine for Methamphetamine Use Disorder: A Randomized Clinical Trial.
  JAMA psychiatry · 2026 · McKetin R, Shoptaw S, Saunders L, et al.
  PMID 41920558DOI 10.1001/jamapsychiatry.2026.0159
• Development and optimization of mirtazapine loaded lipid-based transethosomal gel; in-vitro, ex-vivo and toxicological analysis.
  Pakistan journal of pharmaceutical sciences · 2026 · Ashraf F, Arfat Idrees H, Munir M, et al.
  PMID 41879389DOI 10.36721/PJPS.2026.39.5.REG.14153.1
• Efficacy and Tolerability of Ultra-Low-Dose Mirtazapine in Adult Chronic Insomnia.
  The primary care companion for CNS disorders · 2026 · Berbara R, Gandotra K, Zink E, et al.
  PMID 41861363DOI 10.4088/PCC.25m04074
• Box-Behnken optimized green analytical method for mirtazapine detection using N,P CQDs with quantum mechanical mechanistic elucidation and sustainability assessment.
  Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy · 2026 · Alqahtani AS, Abduljabbar MH, Alnemari RM, et al.
  PMID 41849910DOI 10.1016/j.saa.2026.127731
• Clinical Potential of Mirtazapine in Anxiety and Trauma-Related Disorders: A Systematic Review and Meta-Analysis of Current Evidence.
  Human psychopharmacology · 2026 · Caiazza C, Rago V, Solini N, et al.
  PMID 41817039DOI 10.1002/hup.70037

The 10 most recently updated of 140 ClinicalTrials.gov registrations naming Mirtazapine as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Effects of Mirtazapine on Appetite in Advanced Cancer Patients
  Active not recruiting · Phase 2 · Interventional · 98 enrolled · M.D. Anderson Cancer Center
  NCT00488072updated 2026-06-12
• Depression in the Elderly and Cerebral Amyloid Plaques: Characterization by [18F] AV-45 Affectives Symptoms and Amyloïd Plaques (ASAP)
  Completed · Interventional · 92 enrolled · University Hospital, Tours
  NCT01962753updated 2026-05-19
• Methamphetamine Use Disorder Support in Heart Failure Pilot Study
  Not yet recruiting · Interventional · 50 enrolled · University of Southern California
  NCT07211724updated 2026-05-04
• Repurposing Mirtazapine in Rett Syndrome
  Recruiting · Phase 2 · Interventional · 54 enrolled · University of Trieste
  NCT07430046updated 2026-02-24
• Mirtazapine for Acute and Chronic Post Mastectomy Pain
  Completed · Early phase 1 · Interventional · 62 enrolled · Assiut University
  NCT06499090updated 2026-01-22
• Treating Negative Affect in Low Back Pain Patients
  Completed · Phase 2 · Phase 3 · Interventional · 308 enrolled · Ajay Wasan, MD, Msc
  NCT04747314updated 2026-01-21
• Neurobiological and Genomic Predictors of Relapse in Depression
  Recruiting · Observational · 204 enrolled · Mehmet Kemal Arikan
  NCT07328373updated 2026-01-09
• Novel Pilot Study to Treat Symptoms of IBS With Diarrhea Using Combination Therapy of a Low-FODMAP Diet and a Neuromodulator
  Recruiting · Early phase 1 · Interventional · 20 enrolled · Mayo Clinic
  NCT06684470updated 2025-12-18
• Pilot Study of Mirtazapine for the Dual Tx of Depression and CINV in High-Grade Glioma Pts on TMZ
  Active not recruiting · Phase 2 · Interventional · 120 enrolled · University of California, Irvine
  NCT03935685updated 2025-09-24
• Efficacy and Safety of Low-dose Laser Acupuncture on Treating Insomnia Associated With Major Depressive Disorder
  Not yet recruiting · Interventional · 120 enrolled · Mohammad Farris Iman Leong Bin Abdullah
  NCT06443242updated 2025-09-10

CPIC-curated drug–gene pairs for Mirtazapine. Levels describe the strength of curated evidence and guideline status — never a recommendation to test or to adjust therapy.

• CYP2D6CPIC B/C (provisional)ClinPGx 2A
• FKBP5CPIC D (provisional)ClinPGx 3

Frequently asked questions

How does Mirtazapine work?

The mechanism of action of mirtazapine for the treatment of major depressive disorder, is unclear. However, its efficacy could be mediated through its activity as an antagonist at central presynaptic α 2 -adrenergic inhibitory autoreceptors and heteroreceptors and enhancing central noradrenergic and serotonergic activity.

What is Mirtazapine used for?

According to FDA labeling, Mirtazapine carries indications including: Mirtazapine tablets are indicated for the treatment of major depressive disorder (MDD) in adults [see Clinical Studies (14) ]. Mirtazapine tablets are indicated for the treatment of major depressive disorder (MDD) in adults.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Mirtazapine?

Mirtazapine is classified as Other antidepressants, Adrenergic alpha1-Antagonists, Adrenergic alpha2-Antagonists, Cholinergic Muscarinic Antagonists, Histamine H1 Receptor Antagonists, Monoamine Oxidase Inhibitors, Serotonin 5HT-3 Antagonists, Increased Norepinephrine Activity, Increased Serotonin Activity.

What are the brand names for Mirtazapine?

Mirtazapine is marketed under brand names including Mirataz, Remeron.

What are the contraindications for Mirtazapine?

Mirtazapine labeling lists contraindications including: Mirtazapine tablets are contraindicated in patients: • Taking, or within 14 days of stopping, MAOIs (including the MAOIs linezolid and intravenous methylene blue) because of an increased risk of serotonin syndrome [see Warnings and Precautions (5.3) , Drug Interactions (7) ]. • With a known hypersensitivity to mirtazapine or to any of the excipients in mirtazapine tablets.. Always consult the full prescribing information and a clinician.