Comparative Pharmacology
Head-to-head clinical analysis: DARVON COMPOUND 65 versus OXYCET.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON COMPOUND 65 versus OXYCET.
DARVON COMPOUND-65 vs OXYCET
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.
Oxycodone is a full opioid agonist with relative selectivity for the mu-opioid receptor, though it can interact with other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Acetaminophen is believed to produce analgesia through central action, possibly mediated through inhibition of cyclooxygenase (COX) and activation of descending serotonergic pathways, though the exact mechanism is not fully understood.
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 tablet (325 mg acetaminophen and 5 mg oxycodone) orally every 4 to 6 hours as needed for pain; maximum 12 tablets per day.
None Documented
None Documented
Propoxyphene: 6-12 hours (mean 8 h); nordextropropoxyphene: 22-30 hours (accumulates with repeated dosing; risk of toxicity)
The terminal elimination half-life of oxycodone is approximately 3.5-4 hours for immediate-release formulations. For controlled-release formulations, the half-life is similar due to absorption-limited elimination, but the duration of action is extended due to the formulation. In elderly patients or those with hepatic impairment, half-life may be increased up to 2-fold.
Renal: ~90% as propoxyphene and metabolites (nordextropropoxyphene); biliary/fecal: ~10%
Oxycodone is primarily metabolized in the liver via CYP3A4 to noroxycodone and via CYP2D6 to oxymorphone. Renal excretion accounts for approximately 87% of the administered dose, with 8.1% as unchanged oxycodone, 22.8% as noroxycodone, 9.1% as noroxymorphone, 3.2% as oxymorphone, and others. Fecal excretion is about 10%.
Category C
Category C
Opioid Analgesic Combination
Opioid Analgesic Combination