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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. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.

Drug A

Diazepam

Benzodiazepine

Drug B

Mirtazapine

Noradrenergic and Specific Serotonergic Antidepressant (NaSSA)

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.

What To Do

Your healthcare provider should check your heart's electrical activity with an EKG. Report any fainting or chest palpitations to your doctor immediately.

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).

Mirtazapine Also Interacts With

View all Mirtazapine interactions →

Frequently Asked Questions

Can I take Diazepam and Mirtazapine together?

This is a moderate interaction. Your healthcare provider should check your heart's electrical activity with an EKG. Report any fainting or chest palpitations to your doctor immediately.

How serious is the interaction between Diazepam and Mirtazapine?

This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.

Why do Diazepam and Mirtazapine 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.

Understanding the Diazepam and Mirtazapine Interaction

FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Diazepam belongs to the Benzodiazepine class and Mirtazapine belongs to the Noradrenergic and Specific Serotonergic Antidepressant (NaSSA) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both medications can interfere with the heart's electrical system when used at the same time. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.

Context around a specific patient determines real-world impact. Diazepam has 26 total documented interactions on file in this dataset, and Mirtazapine has 29. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your healthcare provider should check your heart's electrical activity with an EKG. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.

An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Diazepam or Mirtazapine based on a web page, speak with your prescriber or pharmacist before making any change.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.