Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 37 versus NUMORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAGESIC 37 versus NUMORPHAN.
DURAGESIC-37 vs NUMORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Opioid agonist; binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception.
Initial: 25 mcg/hour transdermal patch applied every 72 hours. Titrate based on opioid tolerance. For opioid-naive patients: 12 mcg/hour patch.
Intravenous or subcutaneous: 0.5-2 mg (0.1-0.2 mg/kg for severe pain) every 2-3 hours as needed; not to exceed 20 mg/day.
None Documented
None Documented
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.
Terminal elimination half-life is 2–3 hours in adults; prolonged to 3–4 hours in elderly and up to 15 hours in patients with severe hepatic impairment.
Primarily renal: 75% as metabolites (mostly norfentanyl) and <10% unchanged drug. Fecal: 9% via biliary elimination.
Primarily renal (approximately 70% as unchanged drug, <5% as noroxymorphone and other conjugates); biliary/fecal excretion accounts for ~20%.
Category C
Category C
Opioid Analgesic
Opioid Analgesic