Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 50 versus NUMORPHAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAGESIC 50 versus NUMORPHAN.
DURAGESIC-50 vs NUMORPHAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Fentanyl is a potent synthetic opioid agonist primarily at μ-opioid receptors, with additional weak affinity for κ- and δ-opioid receptors. It increases potassium conductance and decreases calcium influx, leading to hyperpolarization and reduced neurotransmitter release, resulting in analgesia and sedation.
Opioid agonist; binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception.
Apply one 50 mcg/h transdermal system every 72 hours; initiate at 25 mcg/h in opioid-naive patients; titrate based on response and tolerability.
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
Mean terminal elimination half-life 20–27 h (range 13–40 h). Prolonged with hepatic impairment, elderly, or obesity. Clinical context: Requires ~5 days to reach steady state; accumulation risk with continuous use.
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, <10% unchanged fentanyl); ~9% biliary/fecal; <10% excreted in urine as unchanged drug.
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