Comparative Pharmacology
Head-to-head clinical analysis: DARVON COMPOUND 65 versus DARVON W ASA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON COMPOUND 65 versus DARVON W ASA.
DARVON COMPOUND-65 vs DARVON W/ ASA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
DARVON COMPOUND-65 contains propoxyphene, a centrally acting opioid agonist with analgesic effects primarily mediated through mu-opioid receptors. Aspirin inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis. Caffeine is a CNS stimulant with additive analgesic effects.
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.
1 capsule (propoxyphene HCl 65 mg, aspirin 389 mg, caffeine 32.4 mg) orally every 4 hours as needed for pain; maximum 6 capsules per day.
1 capsule (propoxyphene HCl 65 mg / aspirin 650 mg) orally every 4 hours as needed for pain, not to exceed 6 capsules per day.
None Documented
None Documented
Propoxyphene: 6-12 hours (mean 8 h); nordextropropoxyphene: 22-30 hours (accumulates with repeated dosing; risk of toxicity)
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.
Renal: ~90% as propoxyphene and metabolites (nordextropropoxyphene); biliary/fecal: ~10%
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.
Category C
Category C
Opioid Analgesic Combination
Opioid Analgesic Combination