Comparative Pharmacology
Head-to-head clinical analysis: DARVON N versus OXYMORPHONE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON N versus OXYMORPHONE HYDROCHLORIDE.
DARVON-N vs OXYMORPHONE HYDROCHLORIDE
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.
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.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
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; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
Terminal elimination half-life: 7-9 hours (range 4-12 h in elderly/renal impairment). Clinically, steady-state achieved within 24-36 hours.
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
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