Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OXYCODONE AND ACETAMINOPHEN vs ACETAMINOPHEN; OXYCODONE HYDROCHLORIDE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Oxycodone is a full mu-opioid receptor agonist, producing analgesia via activation of descending inhibitory pathways, while acetaminophen is a centrally acting analgesic and antipyretic, likely through inhibition of cyclooxygenase (COX) in the CNS and modulation of serotonergic pathways.
Acetaminophen: cyclooxygenase (COX) inhibitor, primarily in the CNS, reducing prostaglandin synthesis; analgesic and antipyretic. Oxycodone: mu-opioid receptor agonist, inhibiting ascending pain pathways and altering pain perception.
Management of moderate to moderately severe pain (FDA approved),Off-label: acute pain, postoperative pain
Management of moderate to moderately severe pain,Acute pain,Chronic pain
Oral: 5-10 mg oxycodone (with 325-650 mg acetaminophen) every 4-6 hours as needed; maximum oxycodone 60 mg/day (for immediate-release) or acetaminophen 4000 mg/day. Titrate to pain control.
1-2 tablets (equivalent to 325-650 mg acetaminophen / 5-10 mg oxycodone) every 4-6 hours as needed for pain; maximum 12 tablets per day (acetaminophen limit 3900 mg/day or lower if hepatic risk).
Oxycodone: 3-5 hours (immediate-release), 4.5-8 hours (extended-release). Acetaminophen: 1.5-3 hours. Clinical context: Half-life may be prolonged in hepatic impairment, elderly, and renal failure.
Acetaminophen: 2-3 hours (prolonged in hepatic impairment or overdose); Oxycodone: 3-5 hours (immediate-release), 4.5-8 hours (extended-release); Clinical context: Terminal half-life of oxycodone may be prolonged in elderly or patients with renal/hepatic impairment.
Oxycodone is extensively metabolized in the liver via CYP3A4 (primarily) and CYP2D6 (minor) to noroxycodone, oxymorphone, and other metabolites. Acetaminophen is metabolized in the liver mainly via glucuronidation and sulfation with a minor CYP2E1 pathway producing toxic NAPQI.
Acetaminophen: primarily hepatic via glucuronidation (UGT1A1, UGT1A6, UGT1A9), sulfation (SULT1A1), and minor CYP450 (CYP2E1, CYP3A4) to toxic NAPQI. Oxycodone: hepatic via CYP3A4 (major) and CYP2D6 (minor) to active metabolites (noroxycodone, oxymorphone).
Oxycodone: renal (primarily as noroxycodone, oxymorphone, and conjugated metabolites; <10% unchanged). Acetaminophen: renal (85-90% as sulfate and glucuronide conjugates; 2-4% unchanged; 8-10% as cysteine and mercapturate conjugates). Biliary/fecal excretion: minor (<5% for both).
Acetaminophen: renal excretion of metabolites (glucuronide 45-55%, sulfate 20-30%, cysteine and mercapturate conjugates 5-10%) and unchanged drug (<5%); Oxycodone: renal excretion of unchanged drug (approximately 10-19%) and metabolites (noroxycodone, oxymorphone, and their glucuronides) (total renal elimination ~60-87%); fecal elimination of Oxycodone is minimal (<10%).
Oxycodone: 38-45% (primarily to albumin). Acetaminophen: 10-25% (minimal binding).
Acetaminophen: 20-30% (albumin); Oxycodone: 45-50% (albumin).
Oxycodone: 2.6-3.0 L/kg (wide distribution into tissues). Acetaminophen: 0.9-1.0 L/kg (uniformly distributed in body fluids).
Acetaminophen: 0.9-1.0 L/kg (suggests distribution into total body water); Oxycodone: 2.6-4.0 L/kg (suggests extensive tissue distribution).
Oral immediate-release: oxycodone 60-87%, acetaminophen 68-88%. Oral extended-release: oxycodone 60-87% (less variable). Rectal: variable (unspecified for this combination).
Acetaminophen: Oral 85-90%; Oxycodone: Oral 60-87% (first-pass metabolism), Rectal (oxycodone suppository) ~60-80%.
Cr Cl ≥60 m L/min: no adjustment; Cr Cl 30-59 m L/min: acetaminophen no change, oxycodone consider 75% of usual dose; Cr Cl 10-29 m L/min: acetaminophen extend interval to q6h, oxycodone consider 50% of usual dose; Cr Cl <10 m L/min: acetaminophen avoid or 650 mg q8h, oxycodone 50% of usual dose; hemodialysis: acetaminophen 650 mg q8h, oxycodone 25-50% of usual dose.
e GFR 30-60 m L/min: start with 50% of usual dose, increase cautiously; e GFR <30 m L/min: start with 25% of usual dose, extend dosing interval to every 8-12 hours; avoid in dialysis due to oxycodone accumulation.
Child-Pugh A: no adjustment; Child-Pugh B: oxycodone reduce dose by 50%, acetaminophen maximum 2000 mg/day; Child-Pugh C: oxycodone reduce dose by 75%, acetaminophen maximum 2000 mg/day; severe hepatic impairment: avoid acetaminophen component.
Child-Pugh A: no adjustment; Child-Pugh B: start with 50% of usual dose, maximum acetaminophen 2000 mg/day; Child-Pugh C: contraindicated.
Children ≥6 months: 0.05-0.15 mg/kg oxycodone (based on oxycodone component) every 4-6 hours, maximum single dose 5 mg; acetaminophen 10-15 mg/kg/dose, maximum 75 mg/kg/day (up to 4000 mg/day). Weight-based oxycodone not to exceed adult dose.
Weight-based: oxycodone 0.05-0.15 mg/kg/dose (max 5 mg/dose) with acetaminophen 10-15 mg/kg/dose every 4-6 hours; maximum acetaminophen 75 mg/kg/day (not to exceed 4000 mg/day).
Start at 50% of adult dose (oxycodone 2.5-5 mg every 6 hours), titrate cautiously; maximum acetaminophen 3000 mg/day due to decreased hepatic reserves; monitor for renal impairment and avoid if Cr Cl <30 m L/min.
Start with lowest dose (e.g., half of adult dose), titrate slowly; avoid in patients with impaired renal/hepatic function or those at risk for falls; monitor for respiratory depression and constipation.
Risk of addiction, abuse, and misuse; life-threatening respiratory depression; neonatal opioid withdrawal syndrome; accidental ingestion may be fatal; risk of hepatotoxicity with acetaminophen overdose.
Risk of addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion of acetaminophen may cause hepatotoxicity; neonatal opioid withdrawal syndrome; CYP3A4 interaction with benzodiazepines or other CNS depressants.
Addiction, abuse, and misuse; respiratory depression; neonatal opioid withdrawal syndrome; interactions with CNS depressants; hepatotoxicity (acetaminophen); severe hypotension; adrenal insufficiency; seizures; increased risk of overdose in patients with head injury or COPD.
Addiction, abuse, misuse; respiratory depression; accidental exposure; neonatal opioid withdrawal syndrome; hepatotoxicity (acetaminophen); interactions with CNS depressants; elderly or debilitated patients; renal impairment; severe hypotension; adrenal insufficiency; use in patients with head injury.
Hypersensitivity to oxycodone, acetaminophen, or any component; significant respiratory depression; acute or severe bronchial asthma; paralytic ileus; known or suspected gastrointestinal obstruction; severe hepatic impairment (acetaminophen).
Hypersensitivity to acetaminophen or oxycodone; significant respiratory depression; acute or severe bronchial asthma; GI obstruction (e.g., paralytic ileus); severe hepatic impairment; concurrent use with MAOIs or within 14 days.
Avoid alcohol consumption; increases risk of hepatotoxicity from acetaminophen and potentiates CNS depression. Grapefruit juice may increase oxycodone absorption; avoid concurrent use. High-fat meals can delay oxycodone peak concentration, potentially reducing rapid pain relief. No specific restrictions with other foods.
Avoid alcohol. Grapefruit juice may increase oxycodone levels; limit or avoid grapefruit products. High-fat meals may delay absorption of oxycodone. Maintain adequate hydration to prevent constipation.
First trimester: Risk of neural tube defects not significantly increased with therapeutic use; opioid dependence may increase risk of congenital malformations (e.g., gastroschisis). Second/third trimester: Chronic use may cause fetal opioid dependence, leading to neonatal abstinence syndrome (NAS). Late third trimester: Risk of respiratory depression in neonate if used near delivery.
Acetaminophen: Generally considered low risk; no consistent association with major malformations. Oxycodone: First trimester: No increased risk of major malformations in human studies. Second and third trimesters: Risk of neonatal opioid withdrawal syndrome (NOWS) with chronic use; respiratory depression at delivery. No specific human data for combination; extrapolated from individual components.
Excreted into breast milk in low concentrations. M/P ratio for oxycodone: 3.2:1; acetaminophen: approximately 1.0. Considered compatible with breastfeeding with caution; monitor infant for sedation and feeding difficulties. Avoid if maternal codeine use due to CYP2D6 ultrarapid metabolism concerns (though oxycodone less affected).
Acetaminophen: Compatible; M/P ratio ~1.0 (low transfer). Oxycodone: Low levels in milk; M/P ratio ~3.6 (relative infant dose 1.7–6.3% of maternal weight-adjusted dose). Monitor infant for drowsiness, respiratory depression. Use lowest effective dose, shortest duration.
No standard dose adjustment required for maternal pharmacokinetic changes. Increased renal clearance in pregnancy may slightly reduce acetaminophen levels, but therapeutic effect maintained. Oxycodone metabolism via CYP3A4 and 2D6; pregnancy-induced enzyme changes may alter clearance, but clinical significance unclear. Use lowest effective dose, avoid NSAIDs if co-prescribed.
Acetaminophen: No dose adjustment needed; use lowest effective dose. Oxycodone: Pharmacokinetic changes in pregnancy include increased clearance (due to enhanced hepatic metabolism and renal blood flow) and increased volume of distribution, potentially reducing plasma concentrations. Dose may need to be increased (monitor for efficacy and avoid withdrawal); however, use lowest effective dose to minimize neonatal risks. Consider non-opioid alternatives.
Maximum daily acetaminophen dose is 4000 mg from all sources; prescribed combination tablets contribute to this limit. Oxycodone immediate-release duration is 3-6 hours; avoid crushing extended-release formulations. Both components have abuse potential; screen for opioid use disorder. In renal impairment, adjust dosing interval for oxycodone; avoid in Cr Cl <30 m L/min. In hepatic impairment, the acetaminophen component may be hepatotoxic; avoid in severe disease. Coadministration with serotonergic agents may precipitate serotonin syndrome. Naloxone is the reversal agent for oxycodone; acetylcysteine for acetaminophen overdose.
Monitor for acetaminophen hepatotoxicity; maximum daily acetaminophen intake should not exceed 4000 mg. Oxycodone has high abuse potential; consider prescribing naloxone for patients at risk of opioid overdose. Avoid concurrent use of other CNS depressants. Use with caution in elderly or renally impaired patients.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Do not take other products containing acetaminophen (e.g., Tylenol, cold medications) to avoid exceeding the maximum daily dose of 4000 mg.,Avoid alcohol while taking this medication; liver damage risk increases with alcohol use.,Do not crush, break, or chew tablets; swallow whole to avoid rapid release of oxycodone.,This medication can cause drowsiness or dizziness; avoid driving or operating machinery until you know how it affects you.,Store securely out of sight and reach of children; dispose of unused medication via a drug take-back program.,Take with food if nausea occurs; avoid high-fat meals as they may delay absorption.,Do not stop abruptly; withdrawal symptoms may occur. Consult your doctor for a tapering schedule.
Do not exceed 4000 mg of acetaminophen per day from all sources.,This medication can cause drowsiness; avoid driving or operating machinery until you know how it affects you.,Do not consume alcohol while taking this medication.,Take exactly as prescribed; do not crush, chew, or break extended-release tablets.,Store securely out of reach of children and dispose of unused medication properly.,Seek emergency medical attention if you experience difficulty breathing, severe drowsiness, or signs of an allergic reaction.
"Phenobarbital, a potent inducer of cytochrome P450 (CYP) enzymes, particularly CYP3A4 and CYP2D6, significantly increases the hepatic metabolism of oxycodone, a prodrug that requires CYP3A4-mediated N-demethylation to noroxycodone and CYP2D6-mediated O-demethylation to oxymorphone for its analgesic effects. This induction reduces the systemic exposure and peak plasma concentration of active oxycodone and its active metabolite oxymorphone, leading to diminished analgesic efficacy and potential opioid withdrawal symptoms in patients on chronic opioid therapy. Clinically, patients may require substantially higher doses of oxycodone to achieve pain relief, increasing the risk of dose-related adverse effects if the interaction is not recognized."
"The co-administration of oxycodone, a mu-opioid receptor agonist, and gamma-hydroxybutyric acid (GHB), a central nervous system depressant with activity at GABA-B and GHB receptors, results in additive or synergistic respiratory depression and CNS depression. This interaction potentiates the risk of severe hypoventilation, coma, and fatal overdose, especially in non-tolerant users or at therapeutic doses. The combined sedation also increases the likelihood of hypotension, bradycardia, and impaired psychomotor function, necessitating extreme caution."
"The coadministration of oxycodone, a mu-opioid receptor agonist with central nervous system (CNS) depressant effects, and perampanel, a noncompetitive AMPA receptor antagonist that also causes CNS depression, produces additive sedative and respiratory depressant effects. This synergy increases the risk of excessive sedation, impaired cognitive function, and potentially life-threatening respiratory depression. Patients may experience profound somnolence, confusion, and an increased fall risk, necessitating dose adjustments or avoidance."
"Phenobarbital, a potent inducer of cytochrome P450 (CYP) enzymes, particularly CYP3A4 and CYP2D6, significantly increases the hepatic metabolism of oxycodone, a prodrug that requires CYP3A4-mediated N-demethylation to noroxycodone and CYP2D6-mediated O-demethylation to oxymorphone for its analgesic effects. This induction reduces the systemic exposure and peak plasma concentration of active oxycodone and its active metabolite oxymorphone, leading to diminished analgesic efficacy and potential opioid withdrawal symptoms in patients on chronic opioid therapy. Clinically, patients may require substantially higher doses of oxycodone to achieve pain relief, increasing the risk of dose-related adverse effects if the interaction is not recognized."
"The co-administration of oxycodone, a mu-opioid receptor agonist, and gamma-hydroxybutyric acid (GHB), a central nervous system depressant with activity at GABA-B and GHB receptors, results in additive or synergistic respiratory depression and CNS depression. This interaction potentiates the risk of severe hypoventilation, coma, and fatal overdose, especially in non-tolerant users or at therapeutic doses. The combined sedation also increases the likelihood of hypotension, bradycardia, and impaired psychomotor function, necessitating extreme caution."
"The coadministration of oxycodone, a mu-opioid receptor agonist with central nervous system (CNS) depressant effects, and perampanel, a noncompetitive AMPA receptor antagonist that also causes CNS depression, produces additive sedative and respiratory depressant effects. This synergy increases the risk of excessive sedation, impaired cognitive function, and potentially life-threatening respiratory depression. Patients may experience profound somnolence, confusion, and an increased fall risk, necessitating dose adjustments or avoidance."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about OXYCODONE AND ACETAMINOPHEN vs ACETAMINOPHEN; OXYCODONE HYDROCHLORIDE, answered by our medical review team.
OXYCODONE AND ACETAMINOPHEN is a Opioid Agonist that works by Oxycodone is a full mu-opioid receptor agonist, producing analgesia via activation of descending inhibitory pathways, while acetaminophen is a centrally acting analgesic and antipyretic, likely through inhibition of cyclooxygenase (COX) in the CNS and modulation of serotonergic pathways.. ACETAMINOPHEN; OXYCODONE HYDROCHLORIDE is a Opioid Agonist that works by Acetaminophen: cyclooxygenase (COX) inhibitor, primarily in the CNS, reducing prostaglandin synthesis; analgesic and antipyretic. Oxycodone: mu-opioid receptor agonist, inhibiting ascending pain pathways and altering pain perception.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between OXYCODONE AND ACETAMINOPHEN and ACETAMINOPHEN; OXYCODONE HYDROCHLORIDE depend on the specific clinical indication. These are both Opioid Agonist agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of OXYCODONE AND ACETAMINOPHEN is: Oral: 5-10 mg oxycodone (with 325-650 mg acetaminophen) every 4-6 hours as needed; maximum oxycodone 60 mg/day (for immediate-release) or acetaminophen 4000 mg/day. Titrate to pain control.. The standard adult dose of ACETAMINOPHEN; OXYCODONE HYDROCHLORIDE is: 1-2 tablets (equivalent to 325-650 mg acetaminophen / 5-10 mg oxycodone) every 4-6 hours as needed for pain; maximum 12 tablets per day (acetaminophen limit 3900 mg/day or lower if hepatic risk).. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
A moderate-severity drug interaction has been identified when combining OXYCODONE AND ACETAMINOPHEN and ACETAMINOPHEN; OXYCODONE HYDROCHLORIDE. The co-administration of oxycodone, a mu-opioid receptor agonist, and gamma-hydroxybutyric acid (GHB), a central nervous system depressant with activity at GABA-B and GHB receptors, results in additive or synergistic respiratory depression and CNS depression. This interaction potentiates the risk of severe hypoventilation, coma, and fatal overdose, especially in non-tolerant users or at therapeutic doses. The combined sedation also increases the likelihood of hypotension, bradycardia, and impaired psychomotor function, necessitating extreme caution. Consult your prescriber before combining these medications.
The maternal-fetal safety profiles differ. OXYCODONE AND ACETAMINOPHEN is classified as Category D/X. First trimester: Risk of neural tube defects not significantly increased with therapeutic use; opioid dependence may increase risk of congenital malformations (e.g., gastroschisis). ACETAMINOPHEN; OXYCODONE HYDROCHLORIDE is classified as Category D/X. Acetaminophen: Generally considered low risk; no consistent association with major malformations. Oxycodone: First trimester: No increased risk of major malformations in human stud. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.