Comparative Pharmacology
Head-to-head clinical analysis: ARYMO ER versus OPANA ER.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ARYMO ER versus OPANA ER.
ARYMO ER vs OPANA ER
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.
Opana ER (oxymorphone hydrochloride) is a full opioid agonist with relative selectivity for the mu-opioid receptor, although it can interact with other opioid receptors at higher doses. The principal therapeutic action is analgesia via activation of mu-opioid receptors in the central nervous system, leading to altered perception and response to pain.
15 mg to 30 mg orally every 12 hours; titrate to effect; maximum 60 mg per dose.
Initial: 5 mg orally every 12 hours; titrate by 5-10 mg every 12 hours every 3-7 days; maximum 40 mg every 12 hours.
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.
Terminal elimination half-life: 11.1–13.8 hours; clinically relevant as steady-state achieved in 2–3 days
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 (primarily as glucuronide conjugates and unchanged drug): 85-90%; Fecal: <10%
Category C
Category C
Opioid Analgesic
Opioid Analgesic