Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OXYCONTIN vs OPANA ER
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 with relative selectivity for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia with oxycodone. Clinically, dosage is titrated to provide adequate analgesia and may be limited by adverse reactions, including respiratory and CNS depression.
Opana ER (oxymorphone hydrochloride) is a full opioid agonist with relative selectivity for the mu-opioid receptor, although it can interact with other opioid receptors at higher doses. The principal therapeutic action is analgesia via activation of mu-opioid receptors in the central nervous system, leading to altered perception and response to pain.
Management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate,Off-label: Treatment of opioid dependence (as part of substitution therapy)
Management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate
10 mg orally every 12 hours; titrate based on pain severity and prior opioid exposure.
Initial: 5 mg orally every 12 hours; titrate by 5-10 mg every 12 hours every 3-7 days; maximum 40 mg every 12 hours.
4.5-5.0 hours (immediate-release); controlled-release OXYCONTIN has an apparent half-life of 4.5-8.7 hours. Terminal half-life is ~3.5-4 hours for immediate-release, reflecting context-sensitive elimination.
Terminal elimination half-life: 11.1–13.8 hours; clinically relevant as steady-state achieved in 2–3 days
Oxycodone is metabolized primarily via CYP3A4 to noroxycodone (major metabolite) and via CYP2D6 to oxymorphone (minor metabolite). Both metabolites are active, with oxymorphone having higher potency. Oxycodone and its metabolites are conjugated and excreted in urine.
Oxymorphone is extensively metabolized in the liver via conjugation to oxymorphone-3-glucuronide and, to a lesser extent, via reduction to 6-hydroxy-oxymorphone and conjugation. CYP450-mediated metabolism is minimal.
Primarily renal (90% as metabolites, 10% unchanged). Also biliary/fecal (10%).
Renal (primarily as glucuronide conjugates and unchanged drug): 85-90%; Fecal: <10%
38-45%, primarily bound to albumin.
Protein binding: ~80% bound; primarily to albumin
2.6-3.0 L/kg. Extensive tissue distribution, high Vd indicates penetration into peripheral tissues.
Vd: 2.4–3.5 L/kg; indicates extensive tissue distribution
Oral immediate-release: 60-87% (first-pass metabolism). Oral extended-release (Oxy Contin): 60-87% (similar). Intravenous: 100%.
Oral (extended-release): 80–87% (relative to immediate-release oxymorphone)
Cr Cl 30-60 m L/min: reduce dose by 25%; Cr Cl <30 m L/min: reduce dose by 50% and administer every 12 hours; hemodialysis: avoid use.
GFR 30-59 m L/min: initiate at 50% of usual dose; GFR <30 m L/min: avoid use (not recommended).
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: initiate at 50% of usual dose; Child-Pugh Class C: avoid use.
Not approved for pediatric patients <18 years; for children ≥11 years (opioid-tolerant): 0.2 mg/kg orally every 12 hours, titrate; maximum single dose 10 mg.
Not approved for use in pediatric patients (safety and efficacy not established).
Initiate at 5 mg orally every 12 hours; titrate cautiously; monitor for respiratory depression and constipation.
Initiate at 50% of usual dose; titrate cautiously; monitor for respiratory depression and cognitive impairment.
WARNING: ADDICTION, ABUSE, AND MISUSE; LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; NEONATAL OPIOID WITHDRAWAL SYNDROME; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS
WARNING: ADDICTION, ABUSE, AND MISUSE; LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; NEONATAL OPIOID WITHDRAWAL SYNDROME; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS. See full prescribing information for complete boxed warning.
Addiction, abuse, and misuse: Oxy Contin exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Assess each patient's risk prior to prescribing, and monitor all patients regularly for the development of these behaviors or conditions.,Life-threatening respiratory depression: Serious, life-threatening, or fatal respiratory depression may occur. Monitor for respiratory depression, especially during initiation of therapy or following a dose increase. Instruct patients to swallow tablets whole; crushing, chewing, or dissolving can cause rapid release and absorption of a potentially fatal dose.,Accidental ingestion: Accidental ingestion of even one dose of Oxy Contin, especially by children, can result in a fatal overdose of oxycodone.,Neonatal opioid withdrawal syndrome: Prolonged use of Oxy Contin during pregnancy can result in withdrawal in the neonate. Neonatal opioid withdrawal syndrome, unlike opioid withdrawal in adults, may be life-threatening if not recognized and treated.,Risks from concomitant use with benzodiazepines or other CNS depressants: Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for use in patients for whom alternative treatment options are inadequate.
Addiction, abuse, and misuse,Life-threatening respiratory depression,Accidental ingestion,Neonatal opioid withdrawal syndrome,Risks from concomitant use with benzodiazepines or other CNS depressants,Adrenal insufficiency,Severe hypotension,Gastrointestinal effects (constipation, ileus),Seizures,Use in patients with head injury or increased intracranial pressure
Significant respiratory depression,Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment,Known or suspected gastrointestinal obstruction, including paralytic ileus,Hypersensitivity (e.g., anaphylaxis) to oxycodone or any other components of the product
Significant respiratory depression,Acute or severe bronchial asthma in an unmonitored setting or in absence of resuscitative equipment,Known or suspected gastrointestinal obstruction, including paralytic ileus,Hypersensitivity to oxymorphone or any other ingredient in the formulation
Avoid alcohol, which can increase oxycodone absorption and central nervous system depression. Grapefruit juice may alter oxycodone metabolism; limit or avoid consumption. No specific food restrictions, but high-fat meals may slow absorption slightly; take with or without food consistently.
Avoid alcohol as it potentiates CNS depression and increases risk of respiratory depression. Grapefruit juice may increase oxymorphone absorption; consumption should be limited. High-fat meals may delay or decrease absorption; take consistently with or without food to maintain stable levels.
FDA Pregnancy Category C prior to 2020; no adequate studies in pregnant women. First trimester: Limited data suggest possible increased risk of neural tube defects (1.8-fold) and oral clefts (1.5-fold) with opioid use, but confounded by underlying conditions. Second and third trimesters: Chronic use may cause fetal opioid dependence and neonatal abstinence syndrome (NAS); maternal withdrawal may precipitate preterm labor. Avoid prolonged use near term due to risk of neonatal respiratory depression.
FDA Pregnancy Category C. First trimester: No adequate studies; animal studies show increased risk of neural tube defects at high doses. Second/third trimester: Prolonged use may cause neonatal opioid withdrawal syndrome (NOWS), respiratory depression, and low birth weight. Avoid during labor to prevent neonatal respiratory depression.
Oxycodone is excreted into breast milk; relative infant dose is approximately 2.7–8.8% of maternal weight-adjusted dose. M/P ratio unknown. Monitor infant for sedation, respiratory depression, and poor feeding. American Academy of Pediatrics considers oxycodone compatible with breastfeeding with caution; avoid rapid accumulation in mothers with impaired metabolism (CYP2D6 poor metabolizers).
Oxymorphone is excreted in breast milk. M/P ratio unknown. Use caution; monitor infant for drowsiness, respiratory depression, and withdrawal symptoms. The American Academy of Pediatrics recommends use only if benefits outweigh risks.
Pregnancy increases oxycodone clearance by 1.3- to 2.5-fold due to enhanced hepatic metabolism (CYP3A4 and CYP2D6 induction) and increased renal blood flow. Dose adjustments may be necessary to maintain analgesia; clinical monitoring for pain control and withdrawal symptoms is essential. Titrate to effect; avoid abrupt discontinuation. Postpartum clearance returns to baseline over 1-2 weeks.
No specific dose adjustments recommended; however, altered pharmacokinetics (increased volume of distribution, decreased clearance) may require dose titration to effect. Monitor for effectiveness and adverse effects. Higher doses may be needed in third trimester due to opioid tolerance, but taper near term to minimize neonatal withdrawal.
Oxy Contin is an extended-release formulation of oxycodone, indicated for around-the-clock pain management. Do not crush, chew, or break tablets, as this can lead to rapid release and fatal overdose. Use with caution in patients with respiratory compromise, head injury, or increased intracranial pressure. Monitor for signs of misuse, abuse, or addiction. Abrupt discontinuation may precipitate withdrawal; taper dose gradually. Constipation is common; consider prophylactic laxatives. Contraindicated in severe asthma, paralytic ileus, or hypersensitivity.
OPANA ER is an extended-release formulation of oxymorphone, a mu-opioid agonist. It should only be used for opioid-tolerant patients requiring around-the-clock analgesia. Do not crush, chew, or dissolve tablets, as this leads to rapid release and potential fatal overdose. Conversion from other opioids requires careful dose titration due to incomplete cross-tolerance. Use with caution in elderly, cachectic, or debilitated patients due to increased risk of respiratory depression. Concomitant use with CNS depressants (e.g., benzodiazepines, alcohol) increases risk of profound sedation and respiratory depression.
Take Oxy Contin exactly as prescribed, usually every 12 hours. Do not take more or less than directed.,Swallow the tablet whole with water. Do not crush, chew, or break the tablet, as this can cause a dangerous overdose.,Avoid alcohol and other central nervous system depressants (e.g., benzodiazepines, sedatives) as they increase the risk of severe sedation, respiratory depression, and death.,Do not stop taking Oxy Contin suddenly; ask your doctor how to safely discontinue the medication to avoid withdrawal symptoms.,Common side effects include constipation, nausea, drowsiness, and dizziness. Contact your doctor if you experience severe constipation, difficulty breathing, or signs of allergic reaction.,Store Oxy Contin in a secure place out of sight and reach of children and pets. Dispose of unused medication via a drug take-back program.,Do not drive or operate heavy machinery until you know how Oxy Contin affects you.,Inform all healthcare providers that you are taking Oxy Contin, especially before surgery or emergency treatment.
Take exactly as prescribed; do not alter the tablet's integrity (crushing, chewing, dissolving) as it can cause life-threatening overdose.,Avoid alcohol and other CNS depressants (e.g., sedatives, tranquilizers) while taking this medication.,Do not stop abruptly; withdrawal symptoms may occur. Taper under medical supervision.,Store securely away from children and others; accidental ingestion can be fatal.,Report difficulty breathing, excessive sedation, or signs of allergic reaction immediately.,This medication has abuse potential and should be monitored closely.
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 OXYCONTIN vs OPANA ER, answered by our medical review team.
OXYCONTIN is a Opioid Analgesic that works by Oxycodone is a full opioid agonist with relative selectivity for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia with oxycodone. Clinically, dosage is titrated to provide adequate analgesia and may be limited by adverse reactions, including respiratory and CNS depression.. OPANA ER is a Opioid Analgesic that works by Opana ER (oxymorphone hydrochloride) is a full opioid agonist with relative selectivity for the mu-opioid receptor, although it can interact with other opioid receptors at higher doses. The principal therapeutic action is analgesia via activation of mu-opioid receptors in the central nervous system, leading to altered perception and response to pain.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between OXYCONTIN and OPANA ER depend on the specific clinical indication. These are both Opioid Analgesic agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of OXYCONTIN is: 10 mg orally every 12 hours; titrate based on pain severity and prior opioid exposure.. The standard adult dose of OPANA ER is: Initial: 5 mg orally every 12 hours; titrate by 5-10 mg every 12 hours every 3-7 days; maximum 40 mg every 12 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 OXYCONTIN and OPANA ER 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. OXYCONTIN is classified as Category C. FDA Pregnancy Category C prior to 2020; no adequate studies in pregnant women. First trimester: Limited data suggest possible increased risk of neural tube defects (1.8-fold) and o. OPANA ER is classified as Category C. FDA Pregnancy Category C. First trimester: No adequate studies; animal studies show increased risk of neural tube defects at high doses. Second/third trimester: Prolonged use may c. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.