Fentanyl and Morphine: interaction and safety
This source-based reference is not a personal treatment recommendation. The relevance and management of an interaction depend on the exact products, route, dose and clinical situation.
Interaction mechanism
Additive CNS and respiratory depression.
Clinical significance and safety
Fentanyl and morphine can have additive depressant effects, increasing sedation and the risk of slow breathing, coma or death. The prescriber should review the combination and monitor for the effects described; do not adjust the opioid or the other medicine independently. Very slow breathing, inability to wake or collapse requires emergency help.
Using this information
This is a source-based reference record, not a recommendation to combine, stop or change medicines. A missing interaction record does not establish safe use. A qualified healthcare professional should consider the exact products, doses, other medicines and individual health circumstances.