Chlorpromazine and Clozapine Interaction
Drug interaction information between Chlorpromazine and Clozapine.
Chlorpromazine and Clozapine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Chlorpromazine and Clozapine. 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
These two drugs both affect the heart's electrical system in the same way. Using them at the same time can lead to serious heart rhythm problems.
FDA Label Information
Drugs that cause QT prolongation include: specific antipsychotics (e.g., ziprasidone, iloperidone, chlorpromazine, thioridazine, mesoridazine, droperidol, and pimozide), specific antibiotics (e.g., erythromycin, gatifloxacin, moxifloxacin, sparfloxacin), Class 1A antiarrhythmics (e.g., quinidine, procainamide) or Class III antiarrhythmics (e.g., amiodarone, sotalol), and others (e.g., pentamidine, levomethadyl acetate, methadone, halofantrine, mefloquine, dolasetron mesylate, probucol or tacrolimus) [see Warnings and Precautions (5.9) ] .
Chlorpromazine Also Interacts With
- Desmopressin moderate
- Tetrabenazine moderate
- Tranylcypromine moderate
- Zolpidem moderate
- Carbamazepine minor
Clozapine Also Interacts With
- Cyclobenzaprine moderate
- Diphenhydramine moderate
- Fluoxetine moderate
- Sertraline minor
- Escitalopram minor
Frequently Asked Questions
What SPL severity band is on file for Chlorpromazine + Clozapine?
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?
Clozapine has 42 labeled pairs on file vs Chlorpromazine's 11. In the minor band specifically: Chlorpromazine has 7 (also Carbamazepine, Fluoxetine, Meperidine, Pimozide); Clozapine has 39 (also Sertraline, Escitalopram, Bupropion, Duloxetine).
What mechanism field is on file for Chlorpromazine and Clozapine?
These two drugs both affect the heart's electrical system in the same way. Using them at the same time can lead to serious heart rhythm problems.
Clozapine's labeled portfolio outnumbers Chlorpromazine
SPL source-record counts only. This page's band is minor · classes on file: Chlorpromazine (Typical Antipsychotic (Phenothiazine)); Clozapine (Atypical Antipsychotic).
0 major · 4 moderate · 7 minor · 11 total
- Other minor peers for Chlorpromazine
- Carbamazepine
- Fluoxetine
- Meperidine
- Pimozide
0 major · 3 moderate · 39 minor · 42 total
- Other minor peers for Clozapine
- Sertraline
- Escitalopram
- Bupropion
- Duloxetine
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.