Comparative Pharmacology
Head-to-head clinical analysis: DARVOCET N 50 versus DARVON N.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVOCET N 50 versus DARVON N.
DARVOCET-N 50 vs DARVON-N
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Propoxyphene is a weak mu-opioid receptor agonist; it also binds to sigma receptors. Acetaminophen inhibits prostaglandin synthesis via COX-1 and COX-2, thereby reducing pain and fever.
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.
1 tablet (propoxyphene 50 mg, acetaminophen 300 mg) orally every 4 hours as needed for pain, not to exceed 6 tablets per day.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
None Documented
None Documented
Acetaminophen: 1.5-3 hours (therapeutic); 4-6 hours in overdose due to saturation of metabolism. Propoxyphene: 6-12 hours (parent); norpropoxyphene: 30-36 hours (active metabolite, accumulates with repeated dosing).
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
Acetaminophen: renal (90-100% as metabolites within 24h; 2-4% unchanged). Propoxyphene: renal (25-30% unchanged; metabolites) and biliary/fecal (significant enterohepatic circulation).
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Category C
Category C
Opioid Analgesic
Opioid Analgesic