Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
PERCOCET vs ANEXSIA
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 mu-opioid receptor agonist, inhibiting ascending pain pathways and altering pain perception and emotional response. Acetaminophen inhibits cyclooxygenase (COX) in the CNS, reducing prostaglandin synthesis and exerting analgesic and antipyretic effects.
ANEXSIA is a combination of hydrocodone and acetaminophen. Hydrocodone is an opioid agonist that binds to mu-opioid receptors in the central nervous system, altering pain perception and emotional response to pain. Acetaminophen's analgesic mechanism is not fully understood but involves inhibition of COX enzymes in the CNS and modulation of descending serotonergic pathways.
Management of moderate to moderately severe pain (FDA-approved),Off-label: severe pain when other analgesics are inadequate (individualized use)
Relief of moderate to moderately severe pain
One tablet (5 mg oxycodone/325 mg acetaminophen) every 6 hours as needed for pain; maximum 12 tablets per day.
50-100 mg orally every 4-6 hours as needed; maximum 400 mg/day.
Oxycodone: 3.5–4.5 hours (terminal) in normal renal function; prolonged in hepatic/renal impairment (up to 6–12 hours). Acetaminophen: 2–3 hours (terminal) in overdose, extended with hepatic injury.
Terminal elimination half-life is 4-6 hours in adults with normal renal function; prolonged to 12-24 hours in severe renal impairment (Cr Cl <30 m L/min).
Oxycodone: primarily hepatic via CYP3A4 and CYP2D6 to active metabolites (noroxycodone, oxymorphone). Acetaminophen: hepatic via glucuronidation (UGT1A1/1A6), sulfation, and minor CYP2E1 oxidation.
Hydrocodone is metabolized via CYP2D6 and CYP3A4 to hydromorphone and norhydrocodone. Acetaminophen is primarily metabolized via hepatic glucuronidation and sulfation; a minor pathway via CYP2E1 produces NAPQI, which is detoxified by glutathione.
Oxycodone: primarily renal (up to 19% as unchanged drug, 50% as noroxycodone and oxymorphone metabolites); about 10% biliary/fecal. Acetaminophen: renal (majority as glucuronide and sulfate conjugates, about 5% unchanged).
Approximately 70% renal (unchanged drug and metabolites), 20% biliary/fecal, 10% other.
Oxycodone: 38–45% bound to albumin and alpha-1-acid glycoprotein. Acetaminophen: 10–25% bound to albumin (minimal).
Approximately 95% bound to plasma albumin and alpha-1-acid glycoprotein.
Oxycodone: Vd approximately 2.6 L/kg (extensive tissue distribution). Acetaminophen: Vd approximately 0.9 L/kg (total body water).
0.2-0.4 L/kg, indicating limited extravascular distribution primarily confined to plasma and interstitial fluid.
Oxycodone: oral bioavailability 60–87% (immediate-release). Acetaminophen: oral bioavailability 85–98% (first-pass metabolism minimal).
Oral: 80-90%; Intramuscular: 90-100%; Rectal: 70-80%.
GFR >60 m L/min: no adjustment; GFR 30-60 m L/min: dose every 8 hours; GFR <30 m L/min: avoid use or use with extreme caution, consider reducing dose to 50% or extending interval to every 12 hours; not recommended in ESRD.
GFR 30-89 m L/min: no adjustment; GFR 15-29 m L/min: 50% dose reduction; GFR <15 m L/min: avoid use.
Child-Pugh A: no adjustment; Child-Pugh B: reduce total daily dose by 50%; Child-Pugh C: avoid use.
Child-Pugh A: no adjustment; Child-Pugh B: 50% dose reduction; Child-Pugh C: avoid use.
Not FDA-approved for children <18 years; off-label: 0.1-0.2 mg/kg oxycodone (max 5 mg) plus 5-10 mg/kg acetaminophen every 4-6 hours; total acetaminophen not to exceed 75 mg/kg/day or 4 g/day.
1-2 mg/kg/dose orally every 6 hours; maximum 6 mg/kg/day.
Start with low end of dosing, e.g., 2.5 mg oxycodone/325 mg acetaminophen every 6 hours; monitor renal function and avoid >4 g/day acetaminophen; titrate cautiously due to increased sensitivity and fall risk.
Initiate at 25 mg every 6 hours; increase cautiously; monitor renal function.
Risk of addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion of any dosage (especially in children) can be fatal; neonatal opioid withdrawal syndrome with prolonged use during pregnancy; CYP3A4 inhibitors or discontinuation of CYP3A4 inducers may cause fatal respiratory depression; concomitant use with benzodiazepines or other CNS depressants may cause profound sedation, respiratory depression, coma, and death.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants; hepatotoxicity from acetaminophen.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants; severe hypotension; seizures; serotonin syndrome; adrenal insufficiency; hepatotoxicity (acetaminophen); increased risk of pancreatitis (if combined with alcohol); risk of overuse for acetaminophen.
Risk of respiratory depression, especially in elderly or debilitated patients; adrenal insufficiency; severe hypotension; seizures; opioid-induced hyperalgesia; acetaminophen hepatotoxicity (avoid exceeding 4 g/day); serotonin syndrome if used with serotonergic agents.
Hypersensitivity to oxycodone, acetaminophen, or any component; significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment; known or suspected gastrointestinal obstruction, including paralytic ileus; severe hepatic impairment (acetaminophen hepatotoxicity risk).
Hypersensitivity to hydrocodone or acetaminophen; significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting; known or suspected GI obstruction; severe hepatic impairment; concomitant use of MAOIs or within 14 days.
Avoid alcohol and grapefruit juice. Alcohol can potentiate hepatotoxicity from acetaminophen and CNS depression from oxycodone. Grapefruit juice may increase oxycodone levels, enhancing sedative and respiratory depressant effects. No other significant food interactions.
Avoid alcohol; may increase risk of hepatotoxicity and GI bleeding. Limit caffeine intake from coffee, tea, cola, or energy drinks due to added caffeine content. High-fat meals may delay absorption; take on empty stomach for faster onset if tolerated.
Percocet (oxycodone/acetaminophen) is pregnancy category C prior to 30 weeks gestation and category D after 30 weeks. First trimester: No clear evidence of major malformations, but opioid use may be associated with neural tube defects and gastroschisis. Second trimester: Risk of miscarriage, intrauterine growth restriction. Third trimester: Prolonged use can cause neonatal opioid withdrawal syndrome (NOWS) and respiratory depression at delivery. Acetaminophen is considered safe in therapeutic doses but overdose is hepatotoxic to fetus.
First trimester: Data are limited; no increased risk of major malformations reported in small studies. Second and third trimesters: Associated with premature closure of the ductus arteriosus and oligohydramnios due to fetal renal effects; avoid use after 30 weeks gestation.
Oxycodone is excreted into breast milk; relative infant dose is approximately 1-2% of maternal weight-adjusted dose. M/P ratio (milk/plasma) is about 3.2:1 for oxycodone. Acetaminophen M/P ratio ~1.0. Low levels expected, but monitor infant for sedation and poor feeding. Caution with maternal high doses or prolonged use; avoid if mother is ultra-rapid CYP2D6 metabolizer due to risk of toxicity.
Excreted into breast milk in low concentrations (M/P ratio not established). Not recommended during breastfeeding due to potential for adverse effects in the infant, including renal impairment and gastrointestinal bleeding.
During pregnancy, increased plasma volume and hepatic metabolism may require higher doses of oxycodone to achieve analgesic effect. However, due to fetal risks, use lowest effective dose for shortest duration. No specific dose adjustments are validated; clinical response should guide dosing. Acetaminophen dosing remains unchanged but avoid exceeding 3 g/day in pregnancy.
Dose adjustment not generally required; however, due to increased renal clearance in pregnancy, shortened dosing intervals may be necessary for sustained efficacy. Use lowest effective dose for shortest duration.
Percocet contains oxycodone and acetaminophen; the acetaminophen component limits total daily dosing to avoid hepatotoxicity (max 4 g/day in adults, lower in liver disease or alcohol use). Due to oxycodone, it is a Schedule II controlled substance with high abuse potential. Constipation is a common adverse effect; consider prophylactic bowel regimen (e.g., docusate, senna). Respiratory depression risk is dose-related and increased with concurrent CNS depressants. Use with caution in elderly, renal impairment, or sleep apnea. Tolerance and dependence develop with prolonged use. Taper to discontinue after chronic use. Avoid in patients with known hypersensitivity to opioids or acetaminophen.
ANEXSIA is a combination analgesic containing paracetamol, ibuprofen, and caffeine. It is contraindicated in patients with active peptic ulcer disease, severe hepatic impairment, or hypersensitivity to NSAIDs. Avoid concurrent use with other NSAIDs or paracetamol-containing products. Monitor renal function in elderly or dehydrated patients. Caffeine may exacerbate anxiety or insomnia.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Avoid alcohol and other sedatives (e.g., benzodiazepines, muscle relaxants) as they increase risk of severe drowsiness and respiratory depression.,Do not drive or operate heavy machinery until you know how this medication affects you; it may cause dizziness or drowsiness.,Do not exceed 4,000 mg of acetaminophen per day from all sources; check over-the-counter medications for acetaminophen content.,Stop taking and seek immediate medical attention if you experience symptoms of liver damage: yellowing of skin/eyes, dark urine, abdominal pain.,Common side effects include constipation, nausea, vomiting, and drowsiness. Increase fluid and fiber intake to prevent constipation.,This drug has a high risk of addiction and dependence. Store securely out of reach of others. Do not share with others.,Do not suddenly stop taking after prolonged use; a gradual taper is needed to avoid withdrawal symptoms.,Contact your doctor if pain is not controlled or if you experience signs of allergic reaction (rash, swelling, trouble breathing).
Do not exceed recommended dose; overdosage of paracetamol can cause liver damage.,Take with food or milk to reduce gastrointestinal upset.,Avoid alcohol while taking this medication to reduce risk of liver toxicity and GI bleeding.,Discontinue use and consult if signs of allergic reaction, GI bleeding, or liver problems occur.,Caffeine may cause nervousness, insomnia, or increased heart rate; limit caffeine-containing foods and beverages.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about PERCOCET vs ANEXSIA, answered by our medical review team.
PERCOCET is a Opioid Analgesic Combination that works by Oxycodone is a mu-opioid receptor agonist, inhibiting ascending pain pathways and altering pain perception and emotional response. Acetaminophen inhibits cyclooxygenase (COX) in the CNS, reducing prostaglandin synthesis and exerting analgesic and antipyretic effects.. ANEXSIA is a Opioid Analgesic Combination that works by ANEXSIA is a combination of hydrocodone and acetaminophen. Hydrocodone is an opioid agonist that binds to mu-opioid receptors in the central nervous system, altering pain perception and emotional response to pain. Acetaminophen's analgesic mechanism is not fully understood but involves inhibition of COX enzymes in the CNS and modulation of descending serotonergic pathways.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between PERCOCET and ANEXSIA depend on the specific clinical indication. These are both Opioid Analgesic Combination agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of PERCOCET is: One tablet (5 mg oxycodone/325 mg acetaminophen) every 6 hours as needed for pain; maximum 12 tablets per day.. The standard adult dose of ANEXSIA is: 50-100 mg orally every 4-6 hours as needed; maximum 400 mg/day.. 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 PERCOCET and ANEXSIA 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. PERCOCET is classified as Category C. Percocet (oxycodone/acetaminophen) is pregnancy category C prior to 30 weeks gestation and category D after 30 weeks. First trimester: No clear evidence of major malformations, but. ANEXSIA is classified as Category C. First trimester: Data are limited; no increased risk of major malformations reported in small studies. Second and third trimesters: Associated with premature closure of the ductus . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.