Mirtazapine and Warfarin Interaction
Drug interaction information between Mirtazapine and Warfarin.
Mirtazapine and Warfarin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Mirtazapine and Warfarin. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Mirtazapine can increase the blood-thinning effects of warfarin, which may raise your risk of bleeding.
FDA Label Information
Warfarin Clinical Impact The concomitant use of warfarin with mirtazapine may result in an increase in INR [see Clinical Pharmacology (12.3) ]. Intervention Monitor INR during concomitant use of warfarin with mirtazapine. ( 2.5 , 7 ) • Warfarin: Monitor INR during concomitant use.
Mirtazapine Also Interacts With
- Linezolid major
- Alprazolam moderate
- Diazepam moderate
- Phenelzine moderate
- Tranylcypromine moderate
Warfarin Also Interacts With
- Fluoxetine major
- Tamoxifen major
- Ibuprofen moderate
- Aspirin moderate
- Diclofenac moderate
Frequently Asked Questions
What SPL severity band is on file for Mirtazapine + Warfarin?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Warfarin has 163 labeled pairs on file vs Mirtazapine's 29. In the minor band specifically: Mirtazapine has 23 (also Buspirone, Carbamazepine, Lithium, Rifampin); Warfarin has 133 (also Atorvastatin, Amlodipine, Omeprazole, Famotidine).
What mechanism field is on file for Mirtazapine and Warfarin?
Mirtazapine can increase the blood-thinning effects of warfarin, which may raise your risk of bleeding.
Warfarin carries more major-labeled pairs than Mirtazapine
SPL source-record counts only. This page's band is minor · classes on file: Mirtazapine (Noradrenergic and Specific Serotonergic Antidepressant (NaSSA)); Warfarin (Vitamin K Antagonist (Anticoagulant)).
Warfarin has 2 major-labeled pairs vs Mirtazapine's 1. This page itself is in the minor band, not the major band.
1 major · 5 moderate · 23 minor · 29 total
- Other minor peers for Mirtazapine
- Buspirone
- Carbamazepine
- Lithium
- Rifampin
2 major · 28 moderate · 133 minor · 163 total
- Other minor peers for Warfarin
- Atorvastatin
- Amlodipine
- Omeprazole
- Famotidine
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.