NUBAIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NUBAIN (NUBAIN).
Nalbuphine is a mixed opioid agonist-antagonist. It acts as an agonist at kappa opioid receptors and as an antagonist at mu opioid receptors, providing analgesia with a ceiling effect for respiratory depression.
| Metabolism | Primarily hepatic via glucuronidation; CYP450 isoenzymes are not significantly involved. |
| Excretion | Primarily renal (83% as unchanged drug and glucuronide conjugate); fecal excretion accounts for <5%. |
| Half-life | 3.5–5 hours (terminal elimination half-life); clinically, in hepatic or renal impairment, half-life may be prolonged, requiring dose adjustment. |
| Protein binding | Approximately 25–30% bound to plasma proteins (mainly albumin). |
| Volume of Distribution | 4–6 L/kg; indicates extensive tissue distribution. |
| Bioavailability | Oral bioavailability is low (<20%) due to extensive first-pass metabolism; IV, IM, and subcutaneous routes provide 100% bioavailability. |
| Onset of Action | IV: 2–3 minutes; IM: within 15 minutes; Subcutaneous: within 15 minutes. |
| Duration of Action | 3–6 hours (analgesic effect); may be longer with higher doses or in patients with renal/hepatic impairment. |
10-20 mg IV, IM, or SC every 3-6 hours as needed for pain; maximum single dose 20 mg, maximum daily dose 160 mg.
| Dosage form | SOLUTION |
| Renal impairment | CrCl 30-50 mL/min: reduce dose by 50% and administer every 6 hours; CrCl <30 mL/min: reduce dose by 75% and administer every 8 hours. |
| Liver impairment | Child-Pugh Class B: reduce dose by 50% and administer every 6 hours; Child-Pugh Class C: reduce dose by 75% and administer every 8 hours. |
| Pediatric use | Children ≥1 year: 0.1-0.2 mg/kg IV, IM, or SC every 3-6 hours as needed; maximum single dose 20 mg. |
| Geriatric use | Initiate at 50% of the usual adult dose (5-10 mg) and titrate cautiously; maximum single dose 15 mg due to increased sensitivity and risk of respiratory depression. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NUBAIN (NUBAIN).
| Breastfeeding | Excreted in breast milk; M/P ratio unknown. Use caution due to potential for infant sedation and respiratory depression. American Academy of Pediatrics considers use compatible but monitor for drowsiness and feeding difficulties. |
| Teratogenic Risk | Pregnancy Category C. First trimester: insufficient human data; animal studies show increased skeletal anomalies at high doses. Second and third trimesters: prolonged use may cause neonatal opioid withdrawal syndrome (NOWS); avoid chronic use due to risk of respiratory depression in neonate. |
■ FDA Black Box Warning
Risk of respiratory depression, particularly in elderly, cachectic, or debilitated patients; risk of opioid addiction, abuse, and misuse; risk of neonatal opioid withdrawal syndrome with prolonged use during pregnancy; risk of interactions with drugs affecting CYP3A4; risk of serotonin syndrome with concurrent use of serotonergic drugs.
| Serious Effects |
["Hypersensitivity to nalbuphine or any component","Current or suspected opioid dependence (may precipitate acute withdrawal)"]
| Precautions | ["Respiratory depression","Increased intracranial pressure","Hepatic or renal impairment","Biliary tract disease","Concurrent CNS depressants","Opioid dependence (may precipitate withdrawal)","Elderly and debilitated patients"] |
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| Fetal Monitoring |
| Monitor maternal respiratory rate, sedation level, and signs of opioid toxicity. Fetal monitoring: assess fetal heart rate variability and movement; monitor for preterm labor if used near term. Neonatal monitoring after delivery: observe for NOWS (irritability, poor feeding, respiratory distress) for 48–72 hours if used chronically. |
| Fertility Effects | May impair fertility in females via disruption of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion, leading to menstrual irregularities and anovulation. In males, may decrease libido and cause erectile dysfunction. Effects are reversible upon discontinuation. |