Comparative Pharmacology
Head-to-head clinical analysis: DALGAN versus DURAGESIC 37.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DALGAN versus DURAGESIC 37.
DALGAN vs DURAGESIC-37
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Dalgan (generic: dezocine) is a mixed opioid agonist-antagonist that acts as a partial agonist at mu-opioid receptors and a full agonist at kappa-opioid receptors, producing analgesia through modulation of pain signaling in the central nervous system. It also exhibits antagonist activity at mu receptors at higher doses, limiting its abuse potential and respiratory depression compared to full agonists.
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.
Oral: 50-100 mg every 6-8 hours; maximum 400 mg/day. IV: 25-50 mg every 6 hours; maximum 200 mg/day.
Initial: 25 mcg/hour transdermal patch applied every 72 hours. Titrate based on opioid tolerance. For opioid-naive patients: 12 mcg/hour patch.
None Documented
None Documented
Terminal half-life: 2–3 hours; clinically may be prolonged in renal impairment.
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.
Renal: ~90% as unchanged drug and glucuronide conjugates; biliary/fecal: ~10%.
Primarily renal: 75% as metabolites (mostly norfentanyl) and <10% unchanged drug. Fecal: 9% via biliary elimination.
Category C
Category C
Opioid Analgesic
Opioid Analgesic