Drug interactions
Clozapine + Fentanyl iontophoretic transdermal system
Severity: Major
Clozapine and Fentanyl iontophoretic transdermal system: major interaction.
Last updated Sources: UK SmPC
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Fentanyl delivered through an iontophoretic system is a potent opioid, and clozapine adds sedation, hypotension and respiratory depression. The combination can lead to excessive CNS depression, especially in opioid-naive or frail patients.
What this interaction means in plain words
Clozapine and Fentanyl iontophoretic transdermal system can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Additive CNS and respiratory depression with additive hypotension.
What to do
Monitor sedation, respiratory rate and blood pressure, particularly when initiating therapy or changing doses. Use the lowest effective opioid dose and reduce it if excessive sedation occurs.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Clozapine and Fentanyl iontophoretic transdermal system, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Fentanyl iontophoretic transdermal system?
MediHelp rates the interaction as major. Clozapine and Fentanyl iontophoretic transdermal system can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Fentanyl delivered through an iontophoretic system is a potent opioid, and clozapine adds sedation, hypotension and respiratory depression. The combination can lead to excessive CNS depression, especially in opioid-naive or frail patients.
How serious is the interaction between Clozapine and Fentanyl iontophoretic transdermal system?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor sedation, respiratory rate and blood pressure, particularly when initiating therapy or changing doses. Use the lowest effective opioid dose and reduce it if excessive sedation occurs.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
