Comparative Pharmacology
Head-to-head clinical analysis: ARYMO ER versus DURAGESIC 75.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ARYMO ER versus DURAGESIC 75.
ARYMO ER vs DURAGESIC-75
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
ARYMO ER (morphine sulfate) is a full opioid agonist that binds to mu-opioid receptors in the central nervous system (CNS), inhibiting ascending pain pathways and altering pain perception. It also activates descending inhibitory pathways.
Fentanyl is a potent opioid agonist primarily at the mu-opioid receptor, exerting its analgesic effects by mimicking endogenous endorphins and enkephalins to activate G-protein-coupled inwardly rectifying potassium channels, leading to hyperpolarization and reduced neuronal excitability in pain pathways.
15 mg to 30 mg orally every 12 hours; titrate to effect; maximum 60 mg per dose.
Adults: Apply one 75 mcg/hr transdermal patch every 72 hours. Start with lower dose in opioid-naive patients.
None Documented
None Documented
Terminal elimination half-life is approximately 11–13 hours in healthy adults. This extended half-life compared to immediate-release morphine (2–4 hours) allows for once-daily dosing. In elderly or hepatic/renal impairment, half-life may be prolonged up to 22 hours.
22-25 hours after removal of patch; increased in elderly, hepatic/renal impairment
Primarily renal (90%), with approximately 10% excreted unchanged in urine; the remainder as glucuronide conjugates (morphine-3-glucuronide, morphine-6-glucuronide) and minor metabolites. Biliary/fecal excretion accounts for <10%.
Renal (75% as metabolites, <10% unchanged), fecal (25%)
Category C
Category C
Opioid Analgesic
Opioid Analgesic