Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 50 versus LEVORPHANOL TARTRATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DURAGESIC 50 versus LEVORPHANOL TARTRATE.
DURAGESIC-50 vs LEVORPHANOL TARTRATE
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.
Levorphanol is a potent opioid analgesic that acts as a mu-opioid receptor agonist. It also has NMDA receptor antagonist activity, inhibits norepinephrine and serotonin reuptake, and acts as a sigma receptor agonist, contributing to its analgesic effects and reduced tolerance development.
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.
2 mg orally every 6-8 hours as needed for pain; for opioid-tolerant patients, doses up to 4 mg orally every 6-8 hours may be used. Parenterally: 1-2 mg subcutaneously or intramuscularly every 6-8 hours; may be given intravenously at 0.5-1 mg every 6-8 hours.
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.
11-16 hours; extended in hepatic impairment (up to 30 hours).
Primarily renal: ~75% as metabolites (mostly norfentanyl, <10% unchanged fentanyl); ~9% biliary/fecal; <10% excreted in urine as unchanged drug.
Renal: approximately 30% as unchanged drug and 50% as glucuronide conjugates; fecal: 20% via biliary excretion.
Category C
Category C
Opioid Analgesic
Opioid Analgesic