Comparative Pharmacology
Head-to-head clinical analysis: TYLENOL W CODEINE NO 3 versus WESTADONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TYLENOL W CODEINE NO 3 versus WESTADONE.
TYLENOL W/ CODEINE NO. 3 vs WESTADONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Codeine is a prodrug converted to morphine, which acts as a mu-opioid receptor agonist; acetaminophen inhibits cyclooxygenase (COX) and modulates cannabinoid and serotonergic pathways, with central analgesic effect.
Mu-opioid receptor agonist; also acts as an NMDA receptor antagonist and inhibits serotonin and norepinephrine reuptake.
1-2 tablets (300 mg acetaminophen/30 mg codeine per tablet) orally every 4 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 or renal impairment, overdose). Codeine: 2.5-3.5 hours; morphine from codeine: approx 2 hours; prolonged in hepatic or renal impairment.
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: primarily renal (hepatic metabolism followed by renal excretion of metabolites; <5% unchanged). Codeine: renal (primarily as codeine and its metabolites, including morphine, norcodeine, and conjugated forms; 90% excreted in urine, 10% in feces).
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