Comparative Pharmacology
Head-to-head clinical analysis: ASTRAMORPH PF versus DARVON N.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ASTRAMORPH PF versus DARVON N.
ASTRAMORPH PF vs DARVON-N
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Mu-opioid receptor agonist; produces analgesia, sedation, and euphoria by mimicking endogenous endorphins.
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.
Intravenous: 8-10 mg over 2-5 minutes; may be repeated every 8-12 hours as needed. Oral (immediate release): 10-20 mg every 4-6 hours as needed. Oral (extended release): 10-40 mg every 12 hours.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
None Documented
None Documented
Terminal elimination half-life: 2-4 hours; prolonged in renal impairment (up to 12 hours in anuria) and elderly
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
Renal: 70-80% unchanged; Biliary/Fecal: 10-20% as metabolites
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Category C
Category C
Opioid Analgesic
Opioid Analgesic