Comparative Pharmacology
Head-to-head clinical analysis: TYLENOL W CODEINE versus WESTADONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TYLENOL W CODEINE versus WESTADONE.
TYLENOL W/ CODEINE vs WESTADONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Codeine is a prodrug that is metabolized to morphine, which acts as a mu-opioid receptor agonist; acetaminophen inhibits cyclooxygenase (COX) and modulates descending serotonergic pathways.
Mu-opioid receptor agonist; also acts as an NMDA receptor antagonist and inhibits serotonin and norepinephrine reuptake.
1-2 tablets (300-600 mg acetaminophen / 30-60 mg codeine) every 4-6 hours as needed; maximum 12 tablets/day (codeine max 360 mg, acetaminophen max 3600 mg). Route: oral.
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 impairment). Codeine: 2.5-4 hours (slower in CYP2D6 poor metabolizers).
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 glucuronide conjugates (acetaminophen 50-70%, codeine 10-15%), 10-15% as free acetaminophen, <5% free codeine; biliary/fecal: <5%.
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