Comparative Pharmacology
Head-to-head clinical analysis: DARVON versus ROXICODONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON versus ROXICODONE.
DARVON vs ROXICODONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Propoxyphene is a mu-opioid receptor agonist that inhibits ascending pain pathways by binding to opioid receptors in the CNS, altering pain perception. It also has weak local anesthetic effects.
Oxycodone is a full opioid agonist with high affinity for mu-opioid receptors, also binding to kappa and delta receptors. It acts primarily on the central nervous system and gastrointestinal tract.
Propoxyphene hydrochloride (Darvon) for moderate to severe pain: 65 mg orally every 4 hours as needed; maximum 390 mg/day.
5-15 mg orally every 4-6 hours as needed for pain; immediate-release formulation. Maximum 60 mg total daily dose for opioid-naive patients.
None Documented
None Documented
6-12 hours (parent drug); norpropoxyphene half-life 30-36 hours, accumulates with repeated dosing, increasing risk of toxicity.
3.5-5 hours for immediate-release; 4.5-5.5 hours for extended-release. Accumulation may occur with repeated dosing, especially in elderly or hepatic impairment.
Primarily hepatic metabolism to norpropoxyphene, then renal excretion of metabolites; <20% excreted unchanged in urine; minor biliary/fecal elimination.
Renal excretion: 70-80% as unchanged drug and metabolites (oxymorphone, noroxycodone); fecal: 10-20%.
Category C
Category C
Opioid Analgesic
Opioid Analgesic