Lorazepam and Clozapine Interaction
Drug interaction information between Lorazepam and Clozapine.
Lorazepam and Clozapine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Lorazepam and Clozapine. 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.
How They Interact
Combining these medications can cause a dangerous increase in side effects like extreme sleepiness and slowed breathing.
What To Do
Use this combination with extreme caution and watch closely for signs of severe drowsiness or trouble breathing.
FDA Label Information
Concomitant use of clozapine and lorazepam may produce marked sedation, excessive salivation, hypotension, ataxia, delirium, and respiratory arrest.
Lorazepam Also Interacts With
- Valproate minor
- Probenecid minor
- Theophylline minor
- Aripiprazole minor
- Clarithromycin minor
Clozapine Also Interacts With
- Cyclobenzaprine moderate
- Diphenhydramine moderate
- Fluoxetine moderate
- Sertraline minor
- Escitalopram minor
Frequently Asked Questions
Can I take Lorazepam and Clozapine together?
This is a minor interaction. Use this combination with extreme caution and watch closely for signs of severe drowsiness or trouble breathing.
How serious is the interaction between Lorazepam and Clozapine?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Lorazepam and Clozapine interact?
Combining these medications can cause a dangerous increase in side effects like extreme sleepiness and slowed breathing.
Understanding the Lorazepam and Clozapine Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Lorazepam belongs to the Benzodiazepine class and Clozapine belongs to the Atypical Antipsychotic class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Combining these medications can cause a dangerous increase in side effects like extreme sleepiness and slowed breathing. 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. Lorazepam has 11 total documented interactions on file in this dataset, and Clozapine has 42. 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: Use this combination with extreme caution and watch closely for signs of severe drowsiness or trouble breathing. 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 Lorazepam or Clozapine 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.
Read our methodology - how this data is sourced, computed, and verified.