Comparative Pharmacology
Head-to-head clinical analysis: DARVON versus ULTIVA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DARVON versus ULTIVA.
DARVON vs ULTIVA
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.
Selective mu-opioid receptor agonist with rapid onset and short duration of action; produces analgesia without significant histamine release.
Propoxyphene hydrochloride (Darvon) for moderate to severe pain: 65 mg orally every 4 hours as needed; maximum 390 mg/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
6-12 hours (parent drug); norpropoxyphene half-life 30-36 hours, accumulates with repeated dosing, increasing 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 hepatic metabolism to norpropoxyphene, then renal excretion of metabolites; <20% excreted unchanged in urine; minor biliary/fecal elimination.
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