Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OXYCONTIN vs ULTRAM 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.
Tramadol is a centrally acting synthetic opioid analgesic that binds to μ-opioid receptors and inhibits serotonin and norepinephrine reuptake.
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 moderate to moderately severe chronic pain in adults requiring around-the-clock treatment
10 mg orally every 12 hours; titrate based on pain severity and prior opioid exposure.
100 mg orally once daily initially, titrate up to 100 mg twice daily as needed; maximum 200 mg/day.
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.
The terminal elimination half-life of tramadol is approximately 6.3 hours (range 5-9 hours), while its active metabolite M1 has a half-life of about 7.4 hours. Clinically, this supports dosing every 24 hours for the extended-release formulation.
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.
Metabolized primarily via CYP2D6 and CYP3A4; O-desmethyltramadol (M1) is the active metabolite formed by CYP2D6; tramadol and metabolites undergo further conjugation.
Primarily renal (90% as metabolites, 10% unchanged). Also biliary/fecal (10%).
Renal excretion of tramadol and its metabolites accounts for approximately 90% of total elimination. About 10% is excreted unchanged, 30% as O-desmethyltramadol (M1), and the remainder as other minor metabolites. Biliary/fecal excretion is minimal (<10%).
38-45%, primarily bound to albumin.
Approximately 20% bound to plasma proteins, primarily albumin.
2.6-3.0 L/kg. Extensive tissue distribution, high Vd indicates penetration into peripheral tissues.
Volume of distribution is approximately 2.6-3.0 L/kg, indicating extensive tissue distribution beyond plasma volume.
Oral immediate-release: 60-87% (first-pass metabolism). Oral extended-release (Oxy Contin): 60-87% (similar). Intravenous: 100%.
Oral bioavailability of tramadol is approximately 75% after a single dose, increasing to 90-100% upon multiple dosing due to saturable first-pass metabolism. For ULTRAM ER, bioavailability is comparable to immediate-release formulations.
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 30-80 m L/min: no adjustment; GFR <30 m L/min: avoid or extend dosing interval to 12 hours; not recommended in GFR <15 m L/min.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use.
Child-Pugh Class A or B: use with caution, consider reducing total daily dose by 50%; Child-Pugh Class C: contraindicated.
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 recommended for use in pediatric patients <18 years due to risk of respiratory depression and lack of safety data.
Initiate at 5 mg orally every 12 hours; titrate cautiously; monitor for respiratory depression and constipation.
Start at lowest dose (100 mg once daily); titrate cautiously; monitor for CNS and respiratory depression; consider reduced clearance in elderly.
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
Risk of addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion in children can be fatal; neonatal opioid withdrawal syndrome; risk of medication errors with other tramadol products; interactions with CNS depressants; serotonin syndrome; contraindicated in patients with significant respiratory depression; contraindicated in patients with acute or severe bronchial asthma; contraindicated in patients with known or suspected gastrointestinal obstruction; contraindicated in patients with previous hypersensitivity to tramadol.
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.
Risk of respiratory depression; risk of serotonin syndrome with serotonergic drugs; risk of seizures especially in patients with epilepsy or risk factors; risk of adrenal insufficiency; risk of severe hypotension; risk of abuse and dependence; avoidance of abrupt discontinuation; use in renal or hepatic impairment; use in elderly; use in pregnancy and breastfeeding.
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
Hypersensitivity to tramadol or any formulation component; significant respiratory depression; acute or severe bronchial asthma in unmonitored settings; known or suspected gastrointestinal obstruction; concurrent use of MAOIs or within 14 days; use in children <12 years; use in children <18 years after tonsillectomy/adenoidectomy; use in patients with severe hepatic impairment.
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. No specific food restrictions; however, taking with food may reduce nausea. Grapefruit juice may increase tramadol levels; consider limiting grapefruit intake.
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.
Pregnancy category C. First trimester: Limited data; avoid unless benefit outweighs risk due to potential neural tube defects. Second and third trimesters: Fetal dependence, neonatal withdrawal syndrome (seizures, irritability, respiratory depression) if used >7 days. Increased risk of preterm birth and low birth weight.
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).
Ultram ER has an M/P ratio of 0.7-1.3. Small amounts excreted; can cause infant sedation and constipation. Use caution; monitor infant for drowsiness or feeding difficulties.
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 established dose adjustments; pharmacokinetics may change in pregnancy (increased clearance, distribution volume). Use lowest effective dose; avoid sustained release if possible. Caution in third trimester due to risk of 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.
ULTRAM ER contains tramadol, an opioid agonist with SNRI properties. Do not crush or chew extended-release tablets; this can cause rapid release and fatal overdose. Use with caution in patients with seizure disorders or those taking SSRIs, SNRIs, MAOIs, or other drugs that lower seizure threshold. Avoid concurrent use with alcohol or CNS depressants. Monitor for serotonin syndrome when combined with serotonergic drugs. Do not discontinue abruptly after prolonged use; taper to avoid withdrawal symptoms. Not recommended for patients under 18. Crushing extended-release tablets is a safety hazard.
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 ULTRAM ER exactly as prescribed, usually once daily. Swallow tablets whole; do not crush, chew, or break them.,Avoid alcohol and other CNS depressants (e.g., benzodiazepines, sedatives) while taking this medication.,This medication has a risk of addiction, abuse, and misuse. Store securely and dispose of unused tablets properly.,Do not stop taking this medicine suddenly; withdrawal symptoms may occur. Follow your doctor's instructions for tapering.,Seek emergency medical help if you have trouble breathing, severe drowsiness, or slow heartbeat.,Inform your doctor if you have a history of seizures, head injury, or are taking antidepressants like MAOIs, SSRIs, or SNRIs.,ULTRAM ER may cause constipation, nausea, dizziness, or drowsiness. Increase fluid intake and fiber to prevent constipation.,Keep out of reach of children and pets. Accidental ingestion can be fatal.,Do not drive or operate heavy machinery until you know how ULTRAM ER affects you.
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 ULTRAM 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.. ULTRAM ER is a Opioid Analgesic that works by Tramadol is a centrally acting synthetic opioid analgesic that binds to μ-opioid receptors and inhibits serotonin and norepinephrine reuptake.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between OXYCONTIN and ULTRAM 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 ULTRAM ER is: 100 mg orally once daily initially, titrate up to 100 mg twice daily as needed; maximum 200 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 OXYCONTIN and ULTRAM 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. ULTRAM ER is classified as Category C. Pregnancy category C. First trimester: Limited data; avoid unless benefit outweighs risk due to potential neural tube defects. Second and third trimesters: Fetal dependence, neonat. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.