Comparative Pharmacology
Head-to-head clinical analysis: DURAGESIC 37 versus ULTIVA.
Head-to-head clinical analysis: DURAGESIC 37 versus ULTIVA.
DURAGESIC-37 vs ULTIVA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Fentanyl binds to mu-opioid receptors, activating G-protein coupled receptor signaling, leading to inhibition of adenylate cyclase, decreased cAMP production, and modulation of ion channels (increased potassium efflux, decreased calcium influx). This results in reduced neuronal excitability, inhibition of nociceptive transmission, and altered pain perception. Additionally, fentanyl may interact with other opioid receptors (kappa, delta) with lower affinity.
Selective mu-opioid receptor agonist with rapid onset and short duration of action; produces analgesia without significant histamine release.
Initial: 25 mcg/hour transdermal patch applied every 72 hours. Titrate based on opioid tolerance. For opioid-naive patients: 12 mcg/hour patch.
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
Terminal elimination half-life 20-27 hours (range 13-42 h) after transdermal removal; due to continuous absorption from skin depot, effective half-life is longer during patch wear.
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: 75% as metabolites (mostly norfentanyl) and <10% unchanged drug. Fecal: 9% via biliary 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