Comparative Pharmacology
Head-to-head clinical analysis: DARVOCET N 100 versus OPANA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVOCET N 100 versus OPANA.
DARVOCET-N 100 vs OPANA
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.
Mu-opioid receptor agonist; produces analgesia by binding to opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception.
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).
5-20 mg orally every 4-6 hours as needed for pain; extended-release tablets: 5 mg orally every 12 hours, titrated up to 20 mg every 12 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.
Terminal elimination half-life is 11-16 hours (mean 14 hours) in adults; prolonged in hepatic impairment (up to 30 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.
Primarily renal (approximately 90% as conjugated metabolites, 10% unchanged); biliary/fecal elimination accounts for <10%.
Category C
Category C
Opioid Analgesic
Opioid Analgesic