Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OPANA ER vs ACTIQ
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
Opioid agonist; binds to mu-opioid receptors in the CNS, altering pain perception and response.
Management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate
Management of breakthrough pain in cancer patients aged 16 and older who are already receiving and tolerant to opioid therapy for their underlying persistent cancer pain
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.
200 mcg transmucosally, titrated upward as needed; initial dose for opioid-tolerant patients is 200 mcg, with additional doses possible after 15 minutes if needed. Maximum 4 doses per episode. At least 4 hours between episodes.
Terminal elimination half-life: 11.1–13.8 hours; clinically relevant as steady-state achieved in 2–3 days
Terminal half-life 0.83–2 hours (mean 1.3 h) in adults; note that context: transmucosal absorption leads to rapid onset but short duration; half-life is not correlated with clinical effect due to oral transmucosal route and rapid redistribution.
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 hepatic via CYP3A4 to inactive metabolites (norfentanyl, despropionylfentanyl, hydroxyfentanyl) and other metabolites; <7% excreted unchanged in urine.
Renal (primarily as glucuronide conjugates and unchanged drug): 85-90%; Fecal: <10%
Primarily renal as metabolites (about 75% as metabolites, <10% unchanged). Fecal excretion accounts for <9%. Biliary excretion is minor.
Protein binding: ~80% bound; primarily to albumin
Fentanyl is 80–85% bound to plasma proteins (primarily albumin and α1-acid glycoprotein).
Vd: 2.4–3.5 L/kg; indicates extensive tissue distribution
Approximately 4 L/kg (range 3–6 L/kg); large Vd indicates extensive tissue distribution and redistribution contributing to short duration.
Oral (extended-release): 80–87% (relative to immediate-release oxymorphone)
Oral transmucosal: 50% (range 47–54%) relative to IV; variable and enhanced by rapid absorption through buccal mucosa.
GFR 30-59 m L/min: initiate at 50% of usual dose; GFR <30 m L/min: avoid use (not recommended).
No specific GFR-based dose adjustment recommended; use with caution in severe renal impairment (Cr Cl < 30 m L/min) and consider dose reduction due to potential accumulation.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: initiate at 50% of usual dose; Child-Pugh Class C: avoid use.
Child-Pugh Class A/B: No adjustment. Child-Pugh Class C: Reduce initial dose to 100 mcg and titrate slowly; monitor closely for prolonged effects.
Not approved for use in pediatric patients (safety and efficacy not established).
Not approved for pediatric use; safety and efficacy not established in patients under 16 years.
Initiate at 50% of usual dose; titrate cautiously; monitor for respiratory depression and cognitive impairment.
Initiate at 100 mcg transmucosally; titrate slowly due to increased sensitivity and risk of respiratory depression. Monitor for adverse effects.
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.
Risk of respiratory depression, addiction, abuse, and misuse; accidental ingestion can be fatal; concomitant use with benzodiazepines or CNS depressants may cause profound sedation, respiratory depression, coma, and death; not for use in opioid non-tolerant patients; risk of neonatal opioid withdrawal syndrome with prolonged use during pregnancy; serious, life-threatening, or fatal respiratory depression may occur even at recommended doses.
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
Risk of respiratory depression; addiction, abuse, and misuse; interactions with CNS depressants; serotonin syndrome; adrenal insufficiency; severe hypotension; seizures; withdrawal; use in patients with head injuries, increased intracranial pressure, biliary tract disease, pancreatitis; risk of choking with lozenge; oral mucosal irritation; dental caries; hypokalemia; hyponatremia; use in elderly, cachectic, or debilitated patients.
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
Significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment; known or suspected paralytic ileus; hypersensitivity to fentanyl or any component; opioid non-tolerant patients; management of acute or postoperative pain including headache/migraine, dental pain, or emergency department use.
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.
No significant food interactions. Grapefruit juice may increase fentanyl levels, but specific studies with ACTIQ are lacking. Avoid alcohol, as it may increase sedation and respiratory depression risk.
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.
FDA Pregnancy Category C. First trimester: limited human data; animal studies show increased resorptions and fetal growth restriction. Second/third trimester: chronic use may cause neonatal opioid withdrawal syndrome; avoid use during labor due to risk of neonatal respiratory depression.
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.
Excreted in breast milk; M/P ratio not established. Limited data suggest low levels, but risk of infant sedation and respiratory depression. Avoid use while breastfeeding unless potential benefit outweighs risk.
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.
Due to increased plasma volume and hepatic metabolism in pregnancy, dose requirements may increase; adjust based on clinical response and tolerance. Avoid use during labor and delivery due to risk of neonatal respiratory depression; short-term use preferred.
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.
ACTIQ is a transmucosal immediate-release fentanyl formulation indicated for breakthrough cancer pain in opioid-tolerant patients. Initiate with the lowest strength (200 mcg) and titrate upward. Avoid use in opioid-naive patients due to risk of fatal respiratory depression. Place the unit between cheek and lower gum, not sublingually. Instruct patient not to bite or suck the unit. Monitor for sedation and respiratory depression. Multiple units may be used per episode if needed, but wait at least 4 hours before next episode. Dispose of partially used units by flushing down toilet.
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.
Only use ACTIQ if you are already taking regular around-the-clock opioid pain medicine and are tolerant to opioids.,Do not use ACTIQ for short-term pain like after surgery, headache, or dental pain.,Place the unit in your cheek pouch, not under your tongue. Do not chew or suck it.,If you need more than 4 units per day, contact your doctor as your dose may need adjustment.,Store ACTIQ in a safe place away from children, as accidental ingestion can be fatal.,Dispose of unused or partially used units by flushing them down the toilet.
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 OPANA ER vs ACTIQ, answered by our medical review team.
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.. ACTIQ is a Opioid Analgesic that works by Opioid agonist; binds to mu-opioid receptors in the CNS, altering pain perception and response.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between OPANA ER and ACTIQ 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 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.. The standard adult dose of ACTIQ is: 200 mcg transmucosally, titrated upward as needed; initial dose for opioid-tolerant patients is 200 mcg, with additional doses possible after 15 minutes if needed. Maximum 4 doses per episode. At least 4 hours between episodes.. 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 OPANA ER and ACTIQ 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. 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. ACTIQ is classified as Category C. FDA Pregnancy Category C. First trimester: limited human data; animal studies show increased resorptions and fetal growth restriction. Second/third trimester: chronic use may cause. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.