The use of fentanyl patches in pain relief : a prospective observational study in chronic pain patients

Abstract

Fentanyl is a highly potent synthetic opioid whose marked lipophilicity enables efficient transdermal delivery. The transdermal patch provides continuous plasma concentrations, delivering sustained analgesia and greater convenience than oral opioids. Clinical experience, however, highlights considerable inter-individual variability and a tendency for analgesic efficacy to decrease toward the end of the 72-hour dosing interval. Although fentanyl pharmacokinetics are well characterized, few studies have simultaneously captured objective PK metrics (e.g., urine fentanyl and nor-fentanyl levels) and patient-reported pain outcomes—particularly in Malta, where patch therapy is confined to malignant disease. [excerpt]