Comparative Pharmacology
Head-to-head clinical analysis: DARVOCET N 100 versus OXYMORPHONE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVOCET N 100 versus OXYMORPHONE HYDROCHLORIDE.
DARVOCET-N 100 vs OXYMORPHONE HYDROCHLORIDE
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.
Oxymorphone is a semi-synthetic opioid agonist that binds to mu-opioid receptors in the central nervous system, inhibiting ascending pain pathways and altering pain perception and response. It also has affinity for kappa and delta opioid 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).
Initial: 1 mg IV/IM every 3-4 hours as needed for moderate to severe pain; titrate to effect. For patient-controlled analgesia (PCA), 0.5 mg IV loading dose, then 0.25-0.5 mg every 6-15 minutes with lockout. Rectal suppository: 5 mg every 4-6 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: 7-9 hours (range 4-12 h in elderly/renal impairment). Clinically, steady-state achieved within 24-36 hours.
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 (90% as parent drug and metabolites); <1% fecal. Unchanged oxymorphone accounts for ~30% of urinary recovery.
Category C
Category C
Opioid Analgesic
Opioid Analgesic