Diazepam and Mirtazapine Interaction
Drug interaction information between Diazepam and Mirtazapine.
Diazepam and Mirtazapine have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Diazepam and Mirtazapine. 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
Both medications can interfere with the heart's electrical system when used at the same time. This can lead to serious heart rhythm issues that may be life-threatening.
FDA Label Information
Examples diazepam, alprazolam, alcohol Drugs that Prolong QTc Interval Clinical Impact The concomitant use of other drugs which prolong the QTc interval with mirtazapine, increase the risk of QTc prolongation and/or ventricular arrhythmias (e.g., Torsades de Pointes).
Diazepam Also Interacts With
- Clonazepam moderate
- Fluoxetine moderate
- Raloxifene moderate
- Omeprazole minor
- Ketoconazole minor
Mirtazapine Also Interacts With
- Linezolid major
- Alprazolam moderate
- Phenelzine moderate
- Tranylcypromine moderate
- Selegiline moderate
Frequently Asked Questions
What SPL severity band is on file for Diazepam + Mirtazapine?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Mirtazapine has 29 labeled pairs on file vs Diazepam's 26. In the moderate band specifically: Diazepam has 4 (also Clonazepam, Fluoxetine, Raloxifene); Mirtazapine has 5 (also Alprazolam, Phenelzine, Tranylcypromine, Selegiline).
What mechanism field is on file for Diazepam and Mirtazapine?
Both medications can interfere with the heart's electrical system when used at the same time. This can lead to serious heart rhythm issues that may be life-threatening.
Mirtazapine carries more major-labeled pairs than Diazepam
SPL source-record counts only. This page's band is moderate · classes on file: Diazepam (Benzodiazepine); Mirtazapine (Noradrenergic and Specific Serotonergic Antidepressant (NaSSA)).
Mirtazapine has 1 major-labeled pair vs Diazepam's 0. This page itself is in the moderate band, not the major band.
0 major · 4 moderate · 22 minor · 26 total
- Other moderate peers for Diazepam
- Clonazepam
- Fluoxetine
- Raloxifene
1 major · 5 moderate · 23 minor · 29 total
- Other moderate peers for Mirtazapine
- Alprazolam
- Phenelzine
- Tranylcypromine
- Selegiline
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.