Comparative Pharmacology
Head-to-head clinical analysis: DARVON W ASA versus ROXIPRIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON W ASA versus ROXIPRIN.
DARVON W/ ASA vs ROXIPRIN
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.
Roxiprin is a combination analgesic containing rofecoxib (a COX-2 selective NSAID) and paracetamol (acetaminophen, a centrally acting analgesic/antipyretic). Rofecoxib inhibits prostaglandin synthesis by selectively blocking cyclooxygenase-2, reducing pain and inflammation. Paracetamol inhibits cyclooxygenase in the central nervous system and modulates descending serotonergic pathways, providing analgesia and antipyresis.
1 capsule (propoxyphene HCl 65 mg / aspirin 650 mg) orally every 4 hours as needed for pain, not to exceed 6 capsules per day.
500 mg orally every 6 to 8 hours as needed for pain or fever; maximum 2000 mg per day.
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.
2.5 hours (prolonged to 4-6 hours in hepatic impairment; no significant change in renal impairment)
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 (70% as unchanged drug, 20% as glucuronide conjugate); biliary/fecal (10%)
Category C
Category C
Opioid Analgesic Combination
Opioid Analgesic Combination