Comparative Pharmacology
Head-to-head clinical analysis: DARVON N versus STADOL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON N versus STADOL.
DARVON-N vs STADOL
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.
Partial agonist at mu-opioid receptors and agonist at kappa-opioid receptors in the CNS, altering pain perception and emotional response to pain.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
Butorphanol tartrate 1-2 mg IV or IM every 3-4 hours as needed for pain; alternatively, 0.5-1 mg IV every 3-4 hours. For nasal spray: 1 mg (one spray) in one nostril, may repeat in 60-90 minutes if needed; then 1 mg every 3-4 hours as needed.
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: 2.5-4 hours; clinically, prolonged in hepatic impairment (up to 10-12 hours) and elderly
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Renal: 85-90% as unchanged drug and metabolites (primarily as glucuronide conjugates); Fecal: <10%; Biliary: minimal
Category C
Category C
Opioid Analgesic
Opioid Analgesic