Drug Interaction Report

Mirtazapine and Azithromycin: Interaction Details

A pharmacist-reviewed analysis of the Mirtazapine and Azithromycin interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Mirtazapine

Mirataz Remeron
+

Azithromycin

AzaSite Zithromax Zithromax® Zithromax® Single Dose Packets Zithromax® Tri-Paks® Zithromax® Z-Paks® Zmax®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Jul 11, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 78 documented Mirtazapine interactions, 76 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Major

What happens

Increased risk of QT interval prolongation and torsades de pointes

Interaction Deep Dive

Use caution with concomitant use of mirtazapine with other drugs that prolong the QTc interval as it increases the risk of QT prolongation and/or ventricular arrhythmias (eg, torsades de pointes). There have been postmarketing reports with mirtazapine and QT prolongation, torsades de pointes, ventricular tachycardia, and sudden death with the majority of cases occurring in association with overdose, known cardiovascular disease or family history of QT prolongation, or with the concomitant use of QTc-prolonging agents12.

Why it happens (mechanism)

Additive QT interval prolongation

Literature reports

1 report — tap to read

a) There have been postmarketing reports with mirtazapine and QT prolongation, torsades de pointes, ventricular tachycardia, and sudden death with the majority of cases occurring in association with overdose, known cardiovascular disease or family history of QT prolongation, or with the concomitant use of mirtazapine and QTc-prolonging agents 12.

Common questions

Can I take Mirtazapine and Azithromycin together?

Increased risk of QT interval prolongation and torsades de pointes Always confirm with your pharmacist or prescriber before making any change.

How serious is the Mirtazapine and Azithromycin interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "unspecified". The timing of this interaction is not well characterized.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Mirtazapine or Azithromycin need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there a safer alternative to one of these medications for me?

References (2)

  1. Product Information: REMERON(R) oral tablets, mirtazapine oral tablets. Merck Sharp & Dohme Corp (per FDA), Whitehouse Station, NJ, 2020. DailyMed
  2. Product Information: Mirtazapine oral film coated tablets, mirtazapine oral film coated tablets. Apotex Corp (per DailyMed), Weston, FL, 2024. DailyMed
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Mirtazapine

Keep reading about Mirtazapine

All Mirtazapine interactions (78)
Also serious with: Linezolid Injection Ketoconazole Topical Metronidazole Midazolam Injection
Azithromycin

Keep reading about Azithromycin

All Azithromycin interactions (299) Azithromycin drug information
Also serious with: Pimozide Mesoridazine Levoketoconazole Colchicine
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Mirtazapine + Activated Charcoal Grapefruit Lithium St. John's Wort 1,3-dmaa 5-htp Acacia Rigidula Acetyl-l-carnitine + 204 more
Azithromycin + Activated Charcoal American Hellebore Arsenic Cesium Ephedra Grapefruit Oleander Sida Cordifolia + 84 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.