Comparative Pharmacology
Head-to-head clinical analysis: DARVON W ASA versus PERCODAN DEMI.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON W ASA versus PERCODAN DEMI.
DARVON W/ ASA vs PERCODAN-DEMI
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination analgesic: propoxyphene is a weak opioid agonist binding to mu-opioid receptors, inhibiting ascending pain pathways; aspirin irreversibly inhibits cyclooxygenase-1 and -2, reducing prostaglandin synthesis.
Oxycodone is a full mu-opioid receptor agonist; aspirin inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis.
1 capsule (propoxyphene HCl 65 mg / aspirin 650 mg) orally every 4 hours as needed for pain, not to exceed 6 capsules per day.
1 tablet (oxycodone 2.25 mg/aspirin 325 mg) orally every 6 hours as needed for pain; maximum 4 tablets in 24 hours.
None Documented
None Documented
Propoxyphene terminal half-life is 6–12 hours (mean 8 h) in healthy adults; prolonged in hepatic impairment or elderly due to reduced metabolism. Aspirin half-life is 15–20 minutes due to rapid hydrolysis to salicylate.
Oxycodone: 3-4 hours; salicylate (aspirin): 2-3 hours at low doses, 15-30 hours at high doses; terminal half-life clinically relevant for dosing interval (q4-6h).
Renal elimination of propoxyphene and its metabolites accounts for ~70% of a dose, with ~20% excreted unchanged in urine; biliary/fecal elimination accounts for ~10%; aspirin is renally excreted as salicylate and its conjugates.
Renal: ~90% (oxycodone: ~60% as metabolites, ~10% unchanged; aspirin: ~80% as salicylates, ~10% unchanged). Biliary/fecal: minor.
Category C
Category C
Opioid Analgesic Combination
Opioid Analgesic Combination