Comparative Pharmacology
Head-to-head clinical analysis: DARVON N versus ULTIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON N versus ULTIVA.
DARVON-N vs ULTIVA
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.
Selective mu-opioid receptor agonist with rapid onset and short duration of action; produces analgesia without significant histamine release.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
IV bolus: 1 mcg/kg over 30-60 seconds, then continuous IV infusion: 0.25-1 mcg/kg/min for intraoperative analgesia. For general anesthesia induction: 0.5-1 mcg/kg IV bolus; maintenance: 0.25-1 mcg/kg/min IV infusion.
None Documented
None Documented
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
Terminal elimination half-life is 3-10 minutes (context-sensitive half-time is 3-4 minutes independent of infusion duration due to rapid ester hydrolysis). Clinically, recovery is rapid and predictable even after prolonged infusions, with full recovery within 5-10 minutes of discontinuation.
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Remifentanil is metabolized by non-specific blood and tissue esterases to a virtually inactive metabolite (remifentanil acid, 1/4600 potency). Renal excretion accounts for approximately 90% of the metabolite; fecal elimination is minimal (<5%).
Category C
Category C
Opioid Analgesic
Opioid Analgesic