Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ROXICET 5/500 vs ANEXSIA 7.5/325
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 opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. Acetaminophen inhibits cyclooxygenase (COX) enzymes, primarily in the CNS, reducing prostaglandin synthesis and producing analgesic and antipyretic effects.
Hydrocodone is a mu-opioid receptor agonist, producing analgesia and euphoria. Acetaminophen inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis and providing analgesic and antipyretic effects.
Management of moderate to moderately severe pain where treatment with an opioid is appropriate and for which alternative treatments are inadequate
Management of moderate to moderately severe pain where treatment with an opioid is appropriate and for which alternative treatments are inadequate
1-2 tablets (5-10 mg oxycodone / 325-650 mg acetaminophen) orally every 4-6 hours as needed for pain; maximum 12 tablets per day (60 mg oxycodone / 6000 mg acetaminophen) in 24 hours.
1 tablet (hydrocodone 7.5 mg / acetaminophen 325 mg) orally every 4 to 6 hours as needed for pain; maximum 6 tablets per day (hydrocodone 45 mg / acetaminophen 1950 mg).
Oxycodone: 3-5 hours (immediate-release); Acetaminophen: 2-3 hours. In hepatic impairment, oxycodone half-life prolonged (up to 12-15 hours).
Hydrocodone: 3.8-4.5 hours (immediate-release). Acetaminophen: 2-3 hours. Clinical note: Half-life prolonged in hepatic impairment; requires dose adjustment.
Oxycodone is metabolized primarily via CYP3A4 and CYP2D6 to noroxycodone and oxymorphone. Acetaminophen is metabolized mainly via glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation, with minor oxidation by CYP2E1 and CYP1A2 producing N-acetyl-p-benzoquinone imine (NAPQI).
Hydrocodone: CYP3A4 and CYP2D6; Acetaminophen: primarily via glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation, with minor oxidation by CYP2E1.
Oxycodone: primarily hepatic metabolism to noroxycodone, oxymorphone, and conjugates; renal elimination of metabolites (about 60-87% as unchanged and metabolites), fecal < 10%. Acetaminophen: renal elimination of conjugates (90-100%), <5% unchanged.
Renal: ~90-100% as hydrocodone metabolites (conjugated) and unchanged hydrocodone; ~60% as acetaminophen metabolites (glucuronide, sulfate, cysteine); <5% unchanged acetaminophen. Biliary/fecal: <5%.
Oxycodone: ~45% bound to albumin; Acetaminophen: 10-25% bound to albumin.
Hydrocodone: ~20-30% (albumin). Acetaminophen: ~10-25% (albumin).
Oxycodone: 2-3 L/kg (extensive tissue distribution); Acetaminophen: 0.8-1.0 L/kg (distribution throughout body water).
Hydrocodone: 3-4 L/kg (extensive tissue distribution). Acetaminophen: ~1 L/kg (uniformly distributed).
Oxycodone oral: 60-87% (high first-pass metabolism varies); Acetaminophen oral: 80-90%.
Oral: Hydrocodone ~70% (high first-pass metabolism); Acetaminophen ~85-90% (minimal first-pass).
Cr Cl 30-50 m L/min: administer every 6 hours. Cr Cl 10-29 m L/min: administer every 8 hours. Cr Cl <10 m L/min: use not recommended due to oxycodone accumulation; consider alternative.
For GFR 30-59 m L/min: administer every 6 hours; maximum 4 tablets per day. For GFR 15-29 m L/min: administer every 8 hours; maximum 3 tablets per day. For GFR <15 m L/min: not recommended due to accumulation of metabolites.
Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 50% and extend dosing interval to every 8 hours. Child-Pugh Class C: contraindicated due to acetaminophen hepatotoxicity.
Child-Pugh Class A: no adjustment necessary. Child-Pugh Class B: reduce dose by 25-50% and extend dosing interval to every 6-8 hours; maximum 4 tablets per day. Child-Pugh Class C: contraindicated due to risk of hepatotoxicity.
Not typically recommended; use weight-based dosing of oxycodone 0.1-0.2 mg/kg/dose (max 5 mg/dose) every 4-6 hours as needed, with acetaminophen component not to exceed 75 mg/kg/day. Not approved for children <12 years.
Not recommended for pediatric patients; safety and efficacy not established for children under 18 years. For adolescents ≥18 years: adult dosing.
Initiate at lowest dose (one tablet every 6 hours) and titrate cautiously. Monitor for respiratory depression, sedation, and constipation. Avoid doses >4 tablets per day unless tolerated.
Initiate at 1 tablet (hydrocodone 5 mg / acetaminophen 325 mg) every 6 hours as needed; titrate cautiously due to increased sensitivity, decreased renal function, and risk of respiratory depression. Maximum 4 tablets per day.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion of even one dose of oxycodone, especially by children, can cause fatal overdose; neonatal opioid withdrawal syndrome; cytochrome P450 3A4 interaction with concurrent use of benzodiazepines or other CNS depressants; hepatotoxicity due to acetaminophen (dose-related).
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 due to acetaminophen.
Risk of opioid addiction, abuse, and misuse; life-threatening respiratory depression; risk of accidental ingestion; neonatal opioid withdrawal syndrome if used during pregnancy; risk of severe hypotension; risk of hepatotoxicity due to acetaminophen; risk of serotonin syndrome if co-administered with serotonergic drugs; adrenal insufficiency; risk of seizures; risk of increased intracranial pressure; severe renal or hepatic impairment; drug interactions with CNS depressants and CYP3A4 inhibitors/inducers.
Risk of opioid addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use of alcohol, benzodiazepines, or other CNS depressants; hepatotoxicity; severe hypotension; adrenal insufficiency; seizures; GI obstruction; impaired mental/physical abilities; use in elderly, cachectic, or debilitated patients; renal impairment; hepatic impairment; pregnancy; labor and delivery; nursing mothers; pediatric use; driving and operating machinery.
Hypersensitivity to oxycodone, acetaminophen, or any component of the formulation; 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 (for acetaminophen component).
Significant respiratory depression; acute or severe bronchial asthma; known or suspected GI obstruction; hypersensitivity to hydrocodone or acetaminophen; concomitant use of MAOIs or within 14 days of such therapy.
Avoid alcohol and grapefruit juice. High-fat meals may delay absorption of oxycodone, but does not affect total exposure.
Avoid alcohol consumption due to increased risk of acetaminophen hepatotoxicity and CNS depression. No specific food restrictions, but grapefruit juice may theoretically affect hydrocodone metabolism via CYP3A4 inhibition; however, clinical significance is uncertain.
Pregnancy Category C (oxycodone) and D (acetaminophen at high doses). Oxycodone: Risk of neonatal opioid withdrawal syndrome (NOWS) with prolonged use in third trimester; risk of respiratory depression near term. Acetaminophen: Epidemiologic data not conclusively linked to major malformations at therapeutic doses, but high doses may be associated with fetal hepatotoxicity. FDA warns against chronic use during pregnancy due to NOWS.
FDA Category C (hydrocodone) and Category D (acetaminophen) in third trimester. First trimester: Acetaminophen associated with rare gastroschisis; hydrocodone risk of neural tube defects. Second trimester: No major malformations except with prolonged opioid use. Third trimester: Acetaminophen safe; hydrocodone risk of neonatal opioid withdrawal syndrome (NOWS). Avoid near term.
Oxycodone is excreted into breast milk with relative infant dose (RID) of 1.7-6.2% of maternal weight-adjusted dose; M/P ratio not well established (estimated ~1.3-3.7). Acetaminophen RID ~1-2%, M/P ratio ~0.91-1.0. Caution: Monitor infant for somnolence, respiratory depression, poor feeding. Avoid in breastfeeding women with CYP2D6 ultra-rapid metabolizer status due to increased morphine production.
Hydrocodone/acetaminophen excreted in breast milk. M/P ratio unknown. Hydrocodone relative infant dose <3% of weight-adjusted maternal dose. Acetaminophen relative infant dose <2%. Use with caution; monitor infant for sedation, apnea, poor feeding. Highest risk in CYP2D6 ultrarapid metabolizers.
Oxycodone: Increased clearance and volume of distribution in pregnancy may require higher doses for adequate analgesia; dose should be titrated to effect. Acetaminophen: Pharmacokinetic changes minimal at therapeutic doses; no routine dose adjustment needed, but limit to <3000 mg/day to avoid maternal hepatotoxicity. Postpartum: Oxycodone doses may need reduction due to normalization of clearance.
Increased clearance of hydrocodone in pregnancy may require dose adjustment; monitor for inadequate analgesia. Acetaminophen pharmacokinetics unchanged. Avoid high doses (hepatotoxicity risk). Consider baseline hepatic function. No specific dose adjustment recommended; titrate to effect.
ROXICET 5/500 contains oxycodone (5 mg) and acetaminophen (500 mg). The acetaminophen component limits total daily use to avoid hepatotoxicity; maximum 4 g/day from all sources. Oxycodone is a Schedule II controlled substance with high abuse potential. Use with caution in patients with respiratory compromise, head injury, or hepatic impairment. Coadministration with alcohol or other CNS depressants increases sedation and respiratory depression risk. Consider naloxone co-prescription for high-risk patients.
ANEXSIA 7.5/325 (hydrocodone/acetaminophen) carries a boxed warning for acetaminophen hepatotoxicity; maximum acetaminophen dose from all sources should not exceed 4 g/day. Hydrocodone is metabolized by CYP2D6 to hydromorphone; ultrarapid metabolizers may experience toxicity. Avoid concurrent use with other CNS depressants including alcohol. Prescribe with caution in patients with renal impairment (hydrocodone accumulation) or hepatic impairment (acetaminophen toxicity). Monitor for signs of respiratory depression, especially at therapy initiation and dose titration. Use the lowest effective dose for the shortest duration.
Take only as prescribed; do not exceed 8 tablets in 24 hours due to acetaminophen.,Avoid alcohol and medications containing acetaminophen (e.g., Tylenol, cold remedies) to prevent liver damage.,Do not crush or chew tablets—swallow whole.,May cause drowsiness or dizziness; avoid driving or operating machinery until effects known.,Store securely out of reach of others; dispose of unused tablets via drug take-back program.,Do not share with others; misuse can cause addiction, overdose, or death.,Seek emergency help if signs of overdose: slow breathing, extreme drowsiness, confusion, or loss of consciousness.
Do not exceed 6 tablets per day due to acetaminophen content.,Avoid alcohol while taking this medication.,Do not drive or operate heavy machinery until you know how this medication affects you.,Take exactly as prescribed; do not share with others.,Seek emergency help if you experience difficulty breathing, severe drowsiness, or signs of allergic reaction.,Store securely out of reach of children and dispose of unused medication properly.
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 ROXICET 5/500 vs ANEXSIA 7.5/325, answered by our medical review team.
ROXICET 5/500 is a Opioid Analgesic Combination that works by Oxycodone is a full opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. Acetaminophen inhibits cyclooxygenase (COX) enzymes, primarily in the CNS, reducing prostaglandin synthesis and producing analgesic and antipyretic effects.. ANEXSIA 7.5/325 is a Opioid Analgesic Combination that works by Hydrocodone is a mu-opioid receptor agonist, producing analgesia and euphoria. Acetaminophen inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis and providing analgesic and antipyretic effects.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ROXICET 5/500 and ANEXSIA 7.5/325 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 ROXICET 5/500 is: 1-2 tablets (5-10 mg oxycodone / 325-650 mg acetaminophen) orally every 4-6 hours as needed for pain; maximum 12 tablets per day (60 mg oxycodone / 6000 mg acetaminophen) in 24 hours.. The standard adult dose of ANEXSIA 7.5/325 is: 1 tablet (hydrocodone 7.5 mg / acetaminophen 325 mg) orally every 4 to 6 hours as needed for pain; maximum 6 tablets per day (hydrocodone 45 mg / acetaminophen 1950 mg).. 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 ROXICET 5/500 and ANEXSIA 7.5/325 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. ROXICET 5/500 is classified as Category C. Pregnancy Category C (oxycodone) and D (acetaminophen at high doses). Oxycodone: Risk of neonatal opioid withdrawal syndrome (NOWS) with prolonged use in third trimester; risk of r. ANEXSIA 7.5/325 is classified as Category C. FDA Category C (hydrocodone) and Category D (acetaminophen) in third trimester. First trimester: Acetaminophen associated with rare gastroschisis; hydrocodone risk of neural tube d. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.