Comparative Pharmacology
Head-to-head clinical analysis: DARVOCET N 100 versus DEMEROL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVOCET N 100 versus DEMEROL.
DARVOCET-N 100 vs DEMEROL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Propoxyphene is a weak opioid agonist that binds to mu-opioid receptors in the CNS, altering pain perception. Acetaminophen inhibits cyclooxygenase (COX) enzymes centrally, reducing prostaglandin synthesis and providing analgesia.
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.
Darvocet-N 100 contains propoxyphene napsylate 100 mg and acetaminophen 650 mg. For moderate to moderately severe pain, the typical adult dose is 1 tablet orally every 4 hours as needed. Maximum: 6 tablets per day (600 mg propoxyphene napsylate, 3900 mg acetaminophen).
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 (prolonged in elderly and hepatic impairment); norpropoxyphene metabolite: 30-36 hours. Acetaminophen: 1.5-3 hours.
2.5-4 hours; prolonged in hepatic impairment (7-11 hours) and elderly.
Propoxyphene: primarily hepatic metabolism to norpropoxyphene, renal excretion of metabolites (20-25% unchanged propoxyphene). Acetaminophen: renal excretion of glucuronide and sulfate conjugates (90-95% total), 2-4% unchanged.
Renal (90% as metabolites and unchanged drug; ~5% unchanged) and biliary/fecal (minor).
Category C
Category C
Opioid Analgesic
Opioid Analgesic