Product Overview
Generic Name: Oxymorphone hydrochloride
Brand Name: Opana® ER (extended-release)
Manufacturer: Endo Pharmaceuticals Inc.
DEA Schedule: CII (Schedule II Controlled Substance)
Imprint Code: G74 (40mg tablet)
Oxymorphone is a semi-synthetic opioid analgesic derived from thebaine, an alkaloid found in the opium poppy. It is structurally related to morphine, hydromorphone, and oxycodone. The extended-release formulation (Opana ER) was designed for around-the-clock pain management in opioid-tolerant patients only.
Imprint Code Information (G74)
| Property | Information |
|---|---|
| Imprint Code | G74 |
| Strength | 40 mg |
| Color | White |
| Shape | Round |
| Generic Available | Yes |
Potency Comparison
Oxymorphone is approximately:
- 3-5 times more potent than morphine on a milligram basis
- 2-3 times more potent than oxycodone on a milligram basis
- More potent than hydromorphone (Dilaudid) by weight
Indications and Usage
Oxymorphone extended-release (ER) is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.
Limitations of Use:
- Not for use as an as-needed (prn) analgesic for mild to moderate pain
- Not for acute pain, postoperative pain, or breakthrough pain
- Only for opioid-tolerant patients (patients already taking at least 60 mg oral morphine equivalent for at least 7 days)
Dosage and Administration (Educational Reference Only)
Important Safety Limits:
- For opioid-tolerant patients only
- Individualize dosing based on prior opioid experience and response
- Swallow tablets whole. Do not cut, crush, chew, or dissolve
- Crushing or breaking the extended-release tablet can cause rapid release and absorption of a potentially fatal dose of oxymorphone
- Typical starting dose for conversion from other opioids: Individualized based on prior opioid exposure
- Maximum single dose: 40 mg
Mechanism of Action
Oxymorphone is a potent mu-opioid receptor (MOR) agonist. By binding to and activating mu-opioid receptors in the central nervous system (CNS), it inhibits ascending pain pathways, alters pain perception, and produces analgesia, sedation, and euphoria. It has no known ceiling effect for analgesia, meaning higher doses produce increasing pain relief but also increasing risk of respiratory depression and death.
Pharmacokinetics
| Parameter | Information |
|---|---|
| Bioavailability (oral) | Low (approximately 10%) due to first-pass metabolism |
| Time to peak concentration (Tmax) | 2-3 hours (ER formulation) |
| Duration of action (ER) | 12 hours |
| Plasma half-life | 9-11 hours |
BOXED WARNINGS (FDA)
The following boxed warnings apply to oxymorphone (Opana):
- Addiction, Abuse, and Misuse: Oxymorphone exposes users to risks of addiction, abuse, and overdose even at recommended doses.
- Life-Threatening Respiratory Depression: Serious, fatal respiratory depression can occur. Monitor closely, especially during initiation and dose titration.
- Accidental Ingestion: Accidental ingestion of even one dose, especially in children, can be fatal.
- Neonatal Opioid Withdrawal Syndrome (NOWS): Prolonged use during pregnancy can result in life-threatening withdrawal in newborns.
- Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants: Concomitant use can cause profound sedation, respiratory depression, coma, and death.
Contraindications
- 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 to oxymorphone or any component
- Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of MAOI discontinuation
Warnings and Precautions
| Warning/Precaution | Clinical Consideration |
|---|---|
| Respiratory Depression | Monitor for respiratory depression, especially within first 24-72 hours of initiation or dose increase |
| Patient/caregiver education | Educate on safe use, storage, disposal, and overdose reversal with naloxone |
| Adrenal Insufficiency | If diagnosed, treat with corticosteroid replacement; wean opioid if appropriate |
| Severe Hypotension | May cause severe hypotension, including orthostatic hypotension and syncope in ambulatory patients |
| Gastrointestinal Effects | May cause constipation; consider prophylactic laxatives |
Adverse Reactions (Side Effects)
Common (≥5% and greater than placebo):
- Nausea and vomiting
- Constipation (very common)
- Somnolence (drowsiness)
- Dizziness
- Headache
- Pruritus (itching)
- Sweating
- Dry mouth
- Fatigue
- Weakness
Serious Adverse Reactions:
- Respiratory depression: Dose-related, potentially fatal — highest risk during initiation and dose titration
- Severe hypotension: Low blood pressure, especially in patients with impaired ability to maintain blood pressure
- Adrenal insufficiency: Prolonged use may cause secondary adrenal insufficiency
- Serotonin syndrome: When combined with serotonergic drugs (SSRIs, SNRIs, MAOIs)
- Opioid-induced hyperalgesia: Increased pain sensitivity with long-term use
- Androgen deficiency: Low testosterone with long-term use
Tolerance and Dependence
- Tolerance: Higher doses required over time to achieve same analgesic effect
- Physical dependence: Abrupt discontinuation causes withdrawal syndrome
- Addiction (Opioid Use Disorder): Characterized by compulsive use, loss of control, and continued use despite harm
Withdrawal Symptoms:
- Agitation, anxiety, insomnia
- Yawning, tearing, runny nose
- Sweating, chills, piloerection (goosebumps)
- Muscle aches, bone pain
- Nausea, vomiting, diarrhea
- Dilated pupils, tachycardia, hypertension
Withdrawal Management: Abrupt discontinuation should be avoided. Taper dose gradually (10-20% reduction every 2-4 weeks) under medical supervision to prevent withdrawal symptoms.
Overdose Signs and Treatment
Overdose Signs:
- Pinpoint pupils (miosis)
- Respiratory depression (slow, shallow, or stopped breathing)
- Extreme somnolence or unresponsiveness
- Cold, clammy skin
- Cyanosis (blue lips/fingertips)
- Bradycardia, hypotension
- Coma
Overdose Treatment (Emergency):
- Naloxone (Narcan): Opioid antagonist — may require multiple doses due to oxymorphone’s long duration of action
- Call 911 or local emergency services immediately
- Rescue breathing and CPR as needed
- Supportive care (airway management, oxygen, IV fluids)
Drug Interactions
| Drug Class | Interaction | Risk Level |
|---|---|---|
| Benzodiazepines | Additive CNS depression, increased overdose risk | High |
| Alcohol | Profound sedation, respiratory depression, death | High |
| Other opioids | Additive effects, overdose risk | High |
| MAO inhibitors | Potentially fatal reaction | Life-threatening |
| CYP3A4 inhibitors (erythromycin, ketoconazole, grapefruit juice) | Increased oxymorphone levels | Moderate to High |
| CYP3A4 inducers (rifampin, carbamazepine, St. John’s wort) | Decreased oxymorphone levels | Moderate |
Use in Specific Populations
| Population | Consideration |
|---|---|
| Pregnancy | May cause neonatal withdrawal syndrome (NOWS); use only if benefit outweighs risk |
| Breastfeeding | Not recommended — oxymorphone is excreted in human milk |
| Geriatric (≥65 years) | Start with lower doses; increased sensitivity to side effects (dizziness, sedation, constipation) |
| Renal impairment | Dose adjustment recommended — use lower starting doses |
| Hepatic impairment | Significant dose reduction required — contraindicated in severe impairment |
Storage and Disposal
- Storage: Store securely in a locked cabinet at room temperature (59-86°F / 15-30°C). Protect from light and moisture. Keep out of reach of children.
- Disposal: FDA recommends immediate flushing down toilet when no take-back option is available (immediate risk from accidental exposure). Alternatively, use authorized drug take-back program or DEA-registered collector.
Product Identification for G74 40mg Tablet
| Property | Description |
|---|---|
| Imprint Code | G74 |
| Strength | 40 mg |
| Color | White |
| Shape | Round |
| Score | None |
| Manufacturer | Endo Pharmaceuticals |
| Generic Available | Yes |
Legal Status (United States)
Oxymorphone is a Schedule II (CII) controlled substance under the Controlled Substances Act. Key restrictions:
- Prescription required — no refills permitted
- DEA registration required for prescribing and dispensing
- Records must be maintained separately from non-controlled prescriptions
- Illegal to possess without a valid prescription
- Penalties for illegal possession: up to 1 year imprisonment + fines (first offense)
Diversion and Counterfeit Warning (Educational)
Oxymorphone (Opana) has been subject to significant diversion and abuse. Counterfeit tablets, including those imprinted with “G74,” have been found in the illicit market containing fentanyl or other dangerous adulterants. Patients should only obtain oxymorphone from licensed pharmacies with a valid prescription and verify the appearance and imprint of tablets.
Educational Summary
Oxymorphone 40mg tablets (G74) are a Schedule II extended-release opioid analgesic indicated for around-the-clock pain management in opioid-tolerant patients only. The medication carries multiple boxed warnings including addiction, abuse, life-threatening respiratory depression, accidental ingestion, neonatal withdrawal, and fatal interactions with benzodiazepines and other CNS depressants. Oxymorphone is 3-5 times more potent than morphine. The G74 imprint identifies the 40mg strength manufactured by Endo Pharmaceuticals. Only for use in opioid-tolerant patients under strict medical supervision. Illegal possession is a criminal offense.
Note: This information is for educational and awareness purposes only. Oxymorphone is a Schedule II controlled substance with high potential for abuse, addiction, overdose, and death. It is illegal to possess, sell, or distribute without a valid prescription. Nothing here is medical advice or an endorsement of use. If you or someone you know is experiencing a medical emergency, call 911 immediately. If you need help for substance use, contact SAMHSA at 1-800-662-4357.



