Comparative Pharmacology
Head-to-head clinical analysis: OPANA ER versus PROPHENE 65.
Peer-Reviewed Evidence
Head-to-head clinical analysis: OPANA ER versus PROPHENE 65.
OPANA ER vs PROPHENE 65
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Propoxyphene is a weak opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering perception of pain. It also has local anesthetic and moderate antitussive effects.
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.
Propoxyphene napsylate 100 mg orally every 4 hours as needed for pain; maximum 600 mg/day.
None Documented
None Documented
Terminal elimination half-life: 11.1–13.8 hours; clinically relevant as steady-state achieved in 2–3 days
Terminal elimination half-life of propoxyphene: 6-12 hours (mean ~8 hours); norpropoxyphene half-life: 22-36 hours, leading to accumulation with chronic dosing. Clinical context: prolonged half-life in elderly and hepatic impairment increases risk of toxicity.
Renal (primarily as glucuronide conjugates and unchanged drug): 85-90%; Fecal: <10%
Renal elimination of unchanged drug and metabolites: propoxyphene and its major metabolite norpropoxyphene account for ~20-30% as unchanged drug in urine; remainder as conjugated metabolites. Biliary/fecal elimination accounts for <10%.
Category C
Category C
Opioid Analgesic
Opioid Analgesic