[Fentanyl]

Fentanyl is an opioid used for acute pain relief, but its slow elimination may lead to prolonged respiratory depression and sedation. As fatty tissue serves as fentanyl storage and prolongs its elimination, fentanyl should be dosed based on estimated ideal body weight. High-risk patients include those who are overweight, have lung disease and are exposed to other sedative drugs. The risk of severe side effects increases in sleep; delayed side effects may present several hours after administration. This review finds that there is a need for clinical guidelines on the monitoring of patients after treatment with fentanyl.