Comparative Pharmacology
Head-to-head clinical analysis: DEMEROL versus DURAGESIC 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEMEROL versus DURAGESIC 50.
DEMEROL vs DURAGESIC-50
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Meperidine is an opioid agonist that binds to mu-opioid receptors in the central nervous system, mimicking endogenous endorphins to produce analgesia, sedation, and euphoria. It also has additional weak actions at kappa and delta receptors.
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.
50-150 mg IM, IV, or SC every 3-4 hours as needed for pain; oral 50-150 mg every 3-4 hours.
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.
None Documented
None Documented
2.5-4 hours; prolonged in hepatic impairment (7-11 hours) and elderly.
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.
Renal (90% as metabolites and unchanged drug; ~5% unchanged) and biliary/fecal (minor).
Primarily renal: ~75% as metabolites (mostly norfentanyl, <10% unchanged fentanyl); ~9% biliary/fecal; <10% excreted in urine as unchanged drug.
Category C
Category C
Opioid Analgesic
Opioid Analgesic