Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 100 versus DURAGESIC 37.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAGESIC 100 versus DURAGESIC 37.
DURAGESIC-100 vs DURAGESIC-37
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Pure opioid agonist that binds to mu-opioid receptors in the CNS, mimicking endogenous endorphins to inhibit pain transmission. Also interacts with kappa and delta receptors. Therapeutic effects include analgesia, sedation, and euphoria.
Fentanyl binds to mu-opioid receptors, activating G-protein coupled receptor signaling, leading to inhibition of adenylate cyclase, decreased cAMP production, and modulation of ion channels (increased potassium efflux, decreased calcium influx). This results in reduced neuronal excitability, inhibition of nociceptive transmission, and altered pain perception. Additionally, fentanyl may interact with other opioid receptors (kappa, delta) with lower affinity.
Transdermal patch; initial dose based on prior opioid use: for opioid-naive patients, 12 mcg/h every 72 hours; for opioid-tolerant patients, convert using equianalgesic tables; maximum dose 100 mcg/h per patch; apply to non-irritated, non-irradiated skin on chest, back, flank, or upper arm.
Initial: 25 mcg/hour transdermal patch applied every 72 hours. Titrate based on opioid tolerance. For opioid-naive patients: 12 mcg/hour patch.
None Documented
None Documented
Terminal elimination half-life approximately 20–27 hours after transdermal system removal (range 13–25 hours in healthy adults; prolonged in elderly, hepatic impairment, and cachexia).
Terminal elimination half-life 20-27 hours (range 13-42 h) after transdermal removal; due to continuous absorption from skin depot, effective half-life is longer during patch wear.
Renal (primarily as metabolites, <10% unchanged fentanyl); fecal (about 9% of dose).
Primarily renal: 75% as metabolites (mostly norfentanyl) and <10% unchanged drug. Fecal: 9% via biliary elimination.
Category C
Category C
Opioid Analgesic
Opioid Analgesic