Comparative Pharmacology
Head-to-head clinical analysis: DARVON N versus DEMEROL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON N versus DEMEROL.
DARVON-N vs DEMEROL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Propoxyphene is a weak mu-opioid receptor agonist that produces analgesia by binding to opioid receptors in the central nervous system, altering the perception of and response to pain. Its metabolite norpropoxyphene has local anesthetic and sodium channel blocking effects, which may contribute to cardiac toxicity.
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.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
50-150 mg IM, IV, or SC every 3-4 hours as needed for pain; oral 50-150 mg every 3-4 hours.
None Documented
None Documented
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
2.5-4 hours; prolonged in hepatic impairment (7-11 hours) and elderly.
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Renal (90% as metabolites and unchanged drug; ~5% unchanged) and biliary/fecal (minor).
Category C
Category C
Opioid Analgesic
Opioid Analgesic