ROXICET
Clinical safety rating
cautionComprehensive clinical and safety monograph for ROXICET (ROXICET).
Roxicet is a combination of oxycodone, a full mu-opioid receptor agonist, and acetaminophen, which inhibits cyclooxygenase (COX) enzymes, primarily in the central nervous system, to reduce pain perception and fever.
| Metabolism | Oxycodone is primarily metabolized by CYP3A4 and to a lesser extent by CYP2D6; acetaminophen is metabolized via conjugation (glucuronidation and sulfation) and by CYP2E1 (minor, but produces toxic NAPQI). |
| Excretion | Primarily renal (90% as glucuronide conjugates, <10% unchanged). Biliary/fecal excretion is minor (<5%). |
| Half-life | Oxycodone: 3-5 hours (immediate-release); prolonged in hepatic/renal impairment. Acetaminophen: 2-3 hours. |
| Protein binding | Oxycodone: 45-50% (primarily albumin). Acetaminophen: 10-25% (minimal). |
| Volume of Distribution | Oxycodone: 2.6 L/kg; large Vd indicates extensive tissue distribution. |
| Bioavailability | Oral oxycodone: 60-87%; Acetaminophen: 75-85%. |
| Onset of Action | Oral: 15-30 minutes for oxycodone; peak effect 1 hour. |
| Duration of Action | Immediate-release: 4-6 hours for oxycodone; acetaminophen duration 4-6 hours. |
| Molecular Weight | 351.4 |
1-2 tablets (oxycodone 5-10 mg/acetaminophen 325-650 mg) orally every 4-6 hours as needed for pain; maximum acetaminophen 4000 mg/day (3000 mg/day in high-risk patients).
| Dosage form | TABLET |
| Renal impairment | eGFR 30-60 mL/min: reduce dose to 50-75% of usual. eGFR 10-29 mL/min: reduce dose to 25-50% of usual. eGFR <10 mL/min: avoid use or use with extreme caution; reduce dose to 25% and extend dosing interval to every 8-12 hours. |
| Liver impairment | Child-Pugh Class A: no adjustment necessary. Child-Pugh Class B: reduce starting dose by 50% (e.g., oxycodone 2.5-5 mg) and monitor. Child-Pugh Class C: avoid use or use with extreme caution; reduce dose to 25% and extend interval. |
| Pediatric use | Weight-based: oxycodone 0.05-0.15 mg/kg per dose, acetaminophen 10-15 mg/kg per dose, orally every 4-6 hours as needed; maximum acetaminophen 75 mg/kg/day (not to exceed 4000 mg/day) in children ≥12 years; for children <12 years, max acetaminophen 75 mg/kg/day (max 325 mg per dose in children <6 years). |
| Geriatric use | Start with lowest available dose (oxycodone 2.5-5 mg); consider extended dosing interval (every 6-8 hours); monitor renal and hepatic function; avoid in patients with advanced liver disease or GFR <30 mL/min. |
| 1st trimester | Potential teratogenic risk: case-control studies suggest a small increased risk of congenital malformations (e.g., neural tube defects, oral clefts) with first-trimester exposure to oxycodone, though data are conflicting. Avoid use during organogenesis. |
| 2nd trimester | Associated with neonatal withdrawal syndrome with chronic use; monitor fetal growth and amniotic fluid index due to possible oligohydramnios from oxycodone's antidiuretic effect. |
| 3rd trimester | Risk of neonatal opioid withdrawal syndrome and respiratory depression; avoid prolonged use near term. Use lowest effective dose for shortest duration. |
Clinical note
Comprehensive clinical and safety monograph for ROXICET (ROXICET).
| Placental transfer | Transfers across placenta; fetal/maternal plasma ratio ~0.5-1.0. Detectable in amniotic fluid and fetal tissues. |
| Breastfeeding | Oxycodone passes into breast milk in low levels (relative infant dose ~2-3% maternal weight-adjusted dose). Monitor infant for drowsiness, respiratory depression, and poor feeding. American Academy of Pediatrics considers use compatible with caution; avoid if maternal use is prolonged or high-dose. |
| Lactation Rating | L3 (Moderately Safe) - limited data suggest low risk with short-term use. |
| Teratogenic Risk | Pregnancy Category D (FDA). First trimester: Risk of neural tube defects and congenital anomalies with chronic use; no adequate studies. Second trimester: Continued risk of fetal dependence and withdrawal; growth restriction possible. Third trimester: High risk of neonatal opioid withdrawal syndrome (NOWS), respiratory depression, and preterm birth; avoid prolonged use. |
| Fetal Monitoring | Monitor maternal respiratory rate, sedation level, and bowel function. Fetal monitoring: non-stress test and biophysical profile in third trimester for prolonged use. Neonatal monitoring for NOWS (symptoms: irritability, hypertonia, poor feeding, seizures) for at least 48-72 hours after delivery. |
| Fertility Effects | Chronic opioids may cause hypothalamic-pituitary-adrenal axis suppression leading to decreased libido, anovulation, and amenorrhea in females; in males, reduced testosterone levels and sperm motility. Effect on fertility reversible upon discontinuation. |
■ FDA Black Box Warning
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 associated with acetaminophen.
| Serious Effects |
Hypersensitivity to oxycodone, acetaminophen, or any componentSignificant respiratory depressionAcute or severe bronchial asthma in an unmonitored settingKnown or suspected gastrointestinal obstruction (e.g., paralytic ileus)Moderate to severe hepatic impairment
| Precautions | Respiratory depression; increased intracranial pressure; severe hypotension; hepatotoxicity (acetaminophen); opioid-induced hyperalgesia; adrenal insufficiency; severe hypotension; risks of use in patients with gastrointestinal obstruction; seizures; severe renal impairment. |
| Food/Dietary | Avoid alcohol consumption as it increases the risk of hepatotoxicity from acetaminophen and enhances CNS depression from oxycodone. Grapefruit juice may potentiate oxycodone effects by inhibiting CYP3A4 metabolism; avoid concurrent use. High-fat meals may delay absorption of oxycodone but no specific food restrictions otherwise. |
| Clinical Pearls | ROXICET contains oxycodone (an opioid agonist) and acetaminophen. Always assess pain severity and opioid tolerance before prescribing. Monitor for respiratory depression, especially in opioid-naive patients. The maximum daily acetaminophen dose is 4 g (consider hepatic impairment and alcohol use). Avoid concurrent use of other acetaminophen-containing products. Prescribe naloxone for patients at risk of overdose. Use with caution in elderly, renal impairment, and respiratory conditions. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency without consulting your doctor. · This medication can cause drowsiness or dizziness; avoid driving or operating machinery until you know how you react. · Do not consume alcohol or other central nervous system depressants (e.g., benzodiazepines) while taking this medication. · Risk of dependence; do not share this medication with others. Store securely out of reach of children and pets. · Dispose of unused medication via a drug take-back program or mix with unpalatable substances and seal in a plastic bag before discarding. · Contact your doctor if you experience signs of allergic reaction (rash, itching, swelling), severe constipation, nausea/vomiting, or difficulty breathing. · Avoid taking other acetaminophen-containing products; do not exceed 4,000 mg of acetaminophen per day. |
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