Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 37 versus PROPOXYPHENE HYDROCHLORIDE 65.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAGESIC 37 versus PROPOXYPHENE HYDROCHLORIDE 65.
DURAGESIC-37 vs PROPOXYPHENE HYDROCHLORIDE 65
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.
Propoxyphene is a centrally acting opioid agonist that binds to mu-opioid receptors in the central nervous system, inhibiting pain signal transmission and altering pain perception. It also has local anesthetic effects.
Initial: 25 mcg/hour transdermal patch applied every 72 hours. Titrate based on opioid tolerance. For opioid-naive patients: 12 mcg/hour patch.
65 mg orally every 4 hours as needed for pain; maximum 390 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.
6-12 hours (mean ~8 hours); prolonged in hepatic impairment and elderly; accumulation possible with repeated dosing.
Primarily renal: 75% as metabolites (mostly norfentanyl) and <10% unchanged drug. Fecal: 9% via biliary elimination.
Renal excretion of unchanged drug (approximately 20-30%) and metabolites; approximately 40-60% as conjugated metabolites; minor biliary/fecal elimination.
Category C
Category C
Opioid Analgesic
Opioid Analgesic