Comparative Pharmacology
Head-to-head clinical analysis: EMPRACET W CODEINE PHOSPHATE 3 versus WESTADONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMPRACET W CODEINE PHOSPHATE 3 versus WESTADONE.
EMPRACET W/ CODEINE PHOSPHATE #3 vs WESTADONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Codeine is a prodrug metabolized to morphine, which acts as a mu-opioid receptor agonist. Acetaminophen inhibits cyclooxygenase (COX) and modulates descending serotonergic pathways, providing analgesia and antipyresis.
Mu-opioid receptor agonist; also acts as an NMDA receptor antagonist and inhibits serotonin and norepinephrine reuptake.
One or two tablets (300 mg acetaminophen / 30 mg codeine phosphate per tablet) orally every 4 hours as needed for pain, not to exceed 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; codeine: 2.5-3 hours; both prolonged in hepatic impairment; clinical context: dosing every 4-6 hours for acute pain.
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.
Acetaminophen is excreted renally as conjugates (glucuronide 60%, sulfate 30%, cysteine/mercapturate 8%), with <5% unchanged; codeine is metabolized to codeine-6-glucuronide (70%), norcodeine (10%), morphine (10%, via CYP2D6), and conjugates; renal excretion of metabolites; <15% of codeine excreted unchanged; fecal elimination minor.
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