Comparative Pharmacology
Head-to-head clinical analysis: EMPRACET W CODEINE PHOSPHATE 4 versus WESTADONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMPRACET W CODEINE PHOSPHATE 4 versus WESTADONE.
EMPRACET W/ CODEINE PHOSPHATE #4 vs WESTADONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Codeine is a prodrug converted to morphine by CYP2D6, acting as a mu-opioid receptor agonist. Acetaminophen inhibits cyclooxygenase (COX) and modulates descending serotonergic pathways, reducing pain and fever.
Mu-opioid receptor agonist; also acts as an NMDA receptor antagonist and inhibits serotonin and norepinephrine reuptake.
1-2 tablets (acetaminophen 300 mg / codeine phosphate 60 mg per tablet) orally every 4-6 hours as needed for pain; maximum 12 tablets per day.
Oral: 2.5-10 mg every 4-6 hours as needed for pain; maximum 40 mg per day.
None Documented
None Documented
Acetaminophen: 2-3 hours (prolonged in hepatic insufficiency). Codeine: 2.5-3.5 hours; morphine (active metabolite): 1.5-4.5 hours.
Terminal elimination half-life: 15-60 hours (mean ~24 hours). Clinical context: Prolonged half-life supports once-daily dosing in opioid maintenance; accumulation occurs with repeated dosing due to long half-life.
Renal: ~90% as unchanged acetaminophen and metabolites (glucuronide 60%, sulfate 30%, cysteine/mercapturate <5%), 5% unchanged; codeine: ~90% renal as metabolites (codeine-6-glucuronide, norcodeine, morphine, morphine-3-glucuronide, morphine-6-glucuronide), <15% unchanged.
Primarily renal (40-50% as unchanged methadone and its metabolites, 15-20% as metadone-N-oxide), biliary/fecal (5-10%).
Category D/X
Category C
Opioid Agonist
Opioid Agonist