If coadministration of CYP3A4 inhibitors with fentanyl is essential, monitor patients for respiratory depression and sedation at Recurrent intervals and consider fentanyl dose changes until eventually stable drug effects are obtained.lumacaftor/ivacaftor will minimize the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 met

Contraindicated in patients with known or suspected gastrointestinal obstruction, such as paralytic ileus; may perhaps cause spasm of sphincter of Oddi; opioids may possibly cause increases in serum amylase; watch patients with biliary tract condition, including acute pancreatitis, for worsening symptomsnalbuphine decreases effects of fentanyl by p