Comparative Pharmacology
Head-to-head clinical analysis: DARVON N versus ULTRAM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON N versus ULTRAM.
DARVON-N vs ULTRAM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Propoxyphene is a weak mu-opioid receptor agonist that produces analgesia by binding to opioid receptors in the central nervous system, altering the perception of and response to pain. Its metabolite norpropoxyphene has local anesthetic and sodium channel blocking effects, which may contribute to cardiac toxicity.
Tramadol is a centrally acting synthetic opioid analgesic that binds to μ-opioid receptors and inhibits norepinephrine and serotonin reuptake.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
50-100 mg orally every 4-6 hours as needed for pain; maximum 400 mg/day (for extended-release: 100 mg once daily, titrated up to 300 mg once daily).
None Documented
None Documented
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
Tramadol: ~6 hours; M1 metabolite (O-desmethyltramadol): ~7 hours; prolonged in renal/hepatic impairment
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Renal: ~90% (tramadol and metabolites; conjugated metabolites are major), Fecal: ~10%
Category C
Category C
Opioid Analgesic
Opioid Analgesic