Comparative Pharmacology
Head-to-head clinical analysis: NORCO versus PROPHENE 65.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORCO versus PROPHENE 65.
NORCO vs PROPHENE 65
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
NORCO is a combination of hydrocodone, a mu-opioid receptor agonist that inhibits ascending pain pathways and alters pain perception, and acetaminophen, which inhibits cyclooxygenase (COX) enzymes, particularly in the CNS, leading to decreased prostaglandin synthesis and antipyresis.
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.
One tablet (5 mg hydrocodone/325 mg acetaminophen, 7.5 mg/325 mg, 10 mg/325 mg) orally every 4-6 hours as needed for pain. Maximum acetaminophen dose 4000 mg/day; maximum hydrocodone dose 60 mg/day.
Propoxyphene napsylate 100 mg orally every 4 hours as needed for pain; maximum 600 mg/day.
None Documented
None Documented
Hydrocodone: terminal elimination half-life is 3.8 to 6.0 hours (mean 4.5 hours) in adults; prolonged in hepatic or renal impairment. Acetaminophen: half-life 1.5–3 hours.
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.
Hydrocodone: primarily renal (approximately 60% as unchanged drug and metabolites, including norhydrocodone, hydromorphone, and conjugated metabolites). Biliary/fecal excretion accounts for <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