Comparative Pharmacology
Head-to-head clinical analysis: DARVON N versus XARTEMIS XR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON N versus XARTEMIS XR.
DARVON-N vs XARTEMIS XR
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.
XARTEMIS XR is a combination of oxycodone (a full mu-opioid receptor agonist) and acetaminophen (a centrally acting analgesic with antipyretic properties via cyclooxygenase inhibition).
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
1 tablet (oxycodone 7.5 mg / acetaminophen 325 mg) orally every 12 hours; maximum 2 tablets per day.
None Documented
None Documented
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
Oxycodone: 5.3-6.6 hours (immediate-release), extended-release formulation shows prolonged absorption with apparent half-life ~7.2-9.6 hours; naloxone: 2-3 hours.
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Renal: oxycodone and metabolites ~8.8% free oxycodone, ~8.8% noroxycodone, ~33% conjugated metabolites; naloxone: extensive hepatic metabolism, <1% excreted unchanged in urine. Fecal: naloxone metabolites ~17%.
Category C
Category C
Opioid Analgesic
Opioid Analgesic