Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OXYCODONE AND ACETAMINOPHEN vs ADVIL PM
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.
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis. Diphenhydramine is a first-generation antihistamine that antagonizes histamine H1 receptors, causing sedation.
Management of moderate to moderately severe pain (FDA approved),Off-label: acute pain, postoperative pain
Temporary relief of occasional sleeplessness associated with minor aches and pains
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.
Two caplets (ibuprofen 200 mg, diphenhydramine citrate 38 mg) orally at bedtime as needed for insomnia. Maximum: 2 caplets in 24 hours.
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.
Ibuprofen: 2-4 hours (terminal); clinical context: steady state achieved in 1 day, not affected by renal impairment. Diphenhydramine: 4-8 hours (terminal); clinical context: prolonged in 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.
Ibuprofen is primarily metabolized via hepatic oxidation by CYP2C9. Diphenhydramine is metabolized via hepatic N-demethylation and oxidation, primarily by CYP2D6.
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).
Ibuprofen: Renal (90% as metabolites and conjugates, <10% unchanged); Diphenhydramine: Renal (primarily as metabolites, ~1% unchanged). Fecal excretion is negligible for both.
Oxycodone: 38-45% (primarily to albumin). Acetaminophen: 10-25% (minimal binding).
Ibuprofen: >99% bound to albumin; Diphenhydramine: 78-85% bound to albumin.
Oxycodone: 2.6-3.0 L/kg (wide distribution into tissues). Acetaminophen: 0.9-1.0 L/kg (uniformly distributed in body fluids).
Ibuprofen: 0.1-0.2 L/kg; small Vd consistent with high protein binding. Diphenhydramine: 4.5-8.5 L/kg; large Vd indicating 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).
Ibuprofen: 80-100% (oral); Diphenhydramine: 50-70% (oral) due to first-pass metabolism.
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.
Avoid use in GFR <30 m L/min. For GFR 30-59 m L/min, limit to single dose and avoid chronic use. No adjustment needed for GFR ≥60 m L/min.
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.
Contraindicated in Child-Pugh Class C. In Child-Pugh Class B, reduce dose by 50% (max 1 caplet) and monitor for toxicity. No adjustment for Child-Pugh Class A.
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.
Not recommended for children under 12 years. For age ≥12 years, same adult dose: 2 caplets at bedtime.
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 effective dose (1 caplet) at bedtime to minimize anticholinergic and GI adverse effects. Avoid in elderly with cognitive impairment or high fall risk.
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.
NSAIDs cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. NSAIDs are contraindicated in the setting of coronary artery bypass graft (CABG) surgery.
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.
Cardiovascular thrombotic events,Gastrointestinal bleeding, ulceration, and perforation,Renal toxicity,Sedation and impaired cognitive function,Anticholinergic effects,Avoid use with other NSAIDs or antihistamines,Use caution in elderly, renal impairment, hepatic impairment, and pregnancy
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 ibuprofen, diphenhydramine, or any component of the formulation,History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs,Perioperative pain in the setting of coronary artery bypass graft (CABG) surgery,Neonates and premature infants (due to diphenhydramine),Concurrent use with other diphenhydramine products or sedatives
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.
Take with food or milk to reduce GI upset. Avoid alcohol and grapefruit juice. Caffeine may enhance CNS stimulation and should be limited.
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.
Pregnancy Category C/D (after 30 weeks). First trimester: Potential risk of miscarriage and cardiac defects (limited data with NSAIDs). Second trimester: Avoid unless clearly needed; possible oligohydramnios, premature closure of ductus arteriosus, and fetal renal impairment. Third trimester: Contraindicated after 30 weeks due to risk of premature ductus arteriosus closure and persistent pulmonary hypertension.
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).
Diphenhydramine and ibuprofen are excreted into breast milk. M/P ratio not established. Both drugs are considered compatible with breastfeeding in low doses, but theoretical risk of infant sedation (diphenhydramine) and gastrointestinal effects (ibuprofen). Max daily dose for mother should not exceed recommended limits. Monitor infant for drowsiness and poor feeding.
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.
No specific dose adjustment recommended for ibuprofen or diphenhydramine in pregnancy. However, due to altered pharmacokinetics (increased volume of distribution, renal clearance), standard doses may be less effective. Avoid use if possible, especially after 30 weeks. Use lowest effective dose for shortest duration.
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.
Advil PM combines ibuprofen (NSAID) and diphenhydramine (antihistamine). Avoid concomitant use with other NSAIDs or CNS depressants (including alcohol). Use lowest effective dose for shortest duration. Contraindicated in severe hepatic/renal impairment, active GI bleeding, or during third trimester of pregnancy. May cause morning drowsiness due to antihistamine.
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.
Take only one tablet before bedtime; do not exceed recommended dose.,Avoid alcohol and other sedatives while using this medication.,Do not use for more than 10 days for pain or 3 days for fever unless directed by a doctor.,May cause drowsiness; avoid driving or operating machinery until you know how the drug affects you.,Not for use in children under 12 years of age or during pregnancy/breastfeeding without consulting a healthcare provider.,Report signs of stomach bleeding (e.g., black/tarry stools, vomiting blood) or allergic reactions (e.g., facial swelling, difficulty breathing).
"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."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about OXYCODONE AND ACETAMINOPHEN vs ADVIL PM, 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.. ADVIL PM is a NSAID/Sedative Combination that works by Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis. Diphenhydramine is a first-generation antihistamine that antagonizes histamine H1 receptors, causing sedation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between OXYCODONE AND ACETAMINOPHEN and ADVIL PM depend on the specific clinical indication. These are agents from distinct pharmacological classes 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 ADVIL PM is: Two caplets (ibuprofen 200 mg, diphenhydramine citrate 38 mg) orally at bedtime as needed for insomnia. Maximum: 2 caplets in 24 hours.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between OXYCODONE AND ACETAMINOPHEN and ADVIL PM in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
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). ADVIL PM is classified as Category C. Pregnancy Category C/D (after 30 weeks). First trimester: Potential risk of miscarriage and cardiac defects (limited data with NSAIDs). Second trimester: Avoid unless clearly neede. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.