NUBAIN
Clinical safety rating
cautionComprehensive 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. |
| Molecular Weight | 357.45 Da |
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 | Nalbuphine crosses the placenta. Limited human data; associated with respiratory depression in neonates if used near term. Avoid in first trimester unless benefit outweighs risk. |
| 2nd trimester | Similar to t1; use only if clearly needed. Monitor for maternal and fetal effects. |
| 3rd trimester | Use near term may cause neonatal respiratory depression and opioid withdrawal syndrome. Not recommended for prolonged use during labor. |
Clinical note
Comprehensive clinical and safety monograph for NUBAIN (NUBAIN).
| Placental transfer | Nalbuphine crosses the placenta rapidly, with fetal/maternal plasma concentration ratio of approximately 0.7-1.0. |
| Breastfeeding | Nalbuphine is excreted into breast milk in low concentrations. However, potential for infant sedation and respiratory depression exists. Use with caution, especially in preterm or debilitated infants. Monitor for adverse effects. |
| Lactation Rating | L3 (Moderately Safe) |
| 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. |
| 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. |
■ 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 of the formulationConcurrent use or use within 14 days of MAO inhibitors
| 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 |
| Food/Dietary | No specific food interactions. Avoid grapefruit juice as it may affect metabolism of certain opioids, though no direct evidence with nalbuphine. |
| Clinical Pearls | NUBAIN (nalbuphine) is a mixed agonist-antagonist opioid; it can precipitate withdrawal in opioid-dependent patients. It has a ceiling effect for respiratory depression, making it safer than pure agonists in high doses. Onset of action is 2-3 minutes IV, 15 minutes IM/SC; duration is 3-6 hours. Reversal of opioid effects may require higher doses of naloxone due to nalbuphine's strong receptor binding. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency without consulting your doctor. · Avoid alcohol and other central nervous system depressants (e.g., benzodiazepines) as they can increase side effects like drowsiness or slow breathing. · Do not drive or operate machinery until you know how NUBAIN affects you; it may cause dizziness or drowsiness. · Do not stop abruptly; withdrawal symptoms may occur (anxiety, sweating, nausea). · If you have a history of opioid dependence, inform your doctor; NUBAIN may cause withdrawal symptoms. · Report any signs of allergic reaction (rash, itching, swelling) or difficulty breathing immediately. |
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