Drug interactions
Fentanyl + Lorazepam
Severity: Major
Fentanyl and Lorazepam: major interaction.
Last updated
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
Benzodiazepines combined with opioids greatly increase the risk of profound sedation, respiratory depression, coma and death. This combination carries a boxed warning in labeling.
What this interaction means in plain words
Fentanyl and Lorazepam 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 belongs to Musculoskeletal; Lorazepam belongs to Central Nervous System.
Why it happens
Additive CNS and respiratory depression through mu-opioid receptor agonism and GABA-A potentiation.
What to do
Reserve for patients without adequate alternatives, using the lowest doses and shortest durations. Monitor closely for respiratory depression and sedation and consider providing naloxone.
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 Fentanyl and Lorazepam, 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 14 days on the web. No card needed.
Other interactions of Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
Other interactions of Lorazepam
Frequently asked questions
Can I take Fentanyl with Lorazepam?
MediHelp rates the interaction as major. Fentanyl and Lorazepam 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. Benzodiazepines combined with opioids greatly increase the risk of profound sedation, respiratory depression, coma and death. This combination carries a boxed warning in labeling.
How serious is the interaction between Fentanyl and Lorazepam?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reserve for patients without adequate alternatives, using the lowest doses and shortest durations. Monitor closely for respiratory depression and sedation and consider providing naloxone.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl 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.
