What is the typical dose and common side effects of nalbuphine (opioid agonist)?

Nalbuphine Dosing and Side Effects

The typical dose of nalbuphine is 0.5-1 mg IV every 6 hours as needed when used as an adjunct for opioid-induced pruritus, with common side effects including sedation (36%), sweating (9%), nausea/vomiting (6%), dizziness (5%), dry mouth (4%), and headache (3%). 1, 2

Dosing Information

Standard Dosing

• Nalbuphine is typically administered at 0.5-1 mg IV every 6 hours as needed when used as an adjunct for managing opioid-induced pruritus 1
• As an analgesic, nalbuphine is approximately equipotent to morphine on a milligram basis 2, 3
• Nalbuphine exhibits a ceiling effect for respiratory depression at doses above 30 mg, making it potentially safer than pure opioid agonists at higher doses 2

Route of Administration

• Nalbuphine can be administered intravenously, with onset of action occurring within 2-3 minutes 2
• Intramuscular or subcutaneous administration results in onset of action within 15 minutes 2
• The duration of analgesic activity typically ranges from 3-6 hours 2

Side Effect Profile

Common Side Effects

• Sedation is the most frequent adverse reaction, occurring in 36% of patients 2, 4
• Other common side effects include:
  • Sweating/clamminess (9%) 2
  • Nausea/vomiting (6%) 2
  • Dizziness/vertigo (5%) 2
  • Dry mouth (4%) 2
  • Headache (3%) 2

CNS Effects

• Nalbuphine has fewer psychotomimetic effects compared to pentazocine 2, 5
• Less common CNS effects (≤1% incidence) include nervousness, depression, restlessness, euphoria, confusion, hallucinations, and dysphoria 2

Cardiovascular Effects

• Nalbuphine generally produces minimal hemodynamic changes at standard doses 3, 4
• Potential cardiovascular effects include hypertension, hypotension, bradycardia, and tachycardia 2
• Unlike morphine, nalbuphine may not produce hypotension in patients with acute myocardial infarction 4, 6

Respiratory Effects

• At equianalgesic doses, nalbuphine produces respiratory depression comparable to morphine 2, 3
• However, nalbuphine demonstrates a ceiling effect for respiratory depression at doses above 30 mg 2
• When used to reverse opioid-induced respiratory depression, nalbuphine may cause hypertension, increased heart rate, and increased pain 7

Other Adverse Effects

• Gastrointestinal: Cramps, dyspepsia, bitter taste 2
• Respiratory: Depression, dyspnea, asthma 2
• Dermatologic: Itching, burning, urticaria 2
• Miscellaneous: Speech difficulty, urinary urgency, blurred vision, flushing 2

Serious Adverse Effects

• Anaphylactic/anaphylactoid reactions requiring immediate medical treatment 2
• Potential for shock, respiratory distress/arrest, bradycardia, cardiac arrest, hypotension, or laryngeal edema 2
• Serotonin syndrome may occur with concomitant use of serotonergic drugs 2
• Adrenal insufficiency has been reported with opioid use lasting more than one month 2

Special Considerations

Opioid Antagonist Properties

• Nalbuphine is primarily a kappa agonist/partial mu antagonist analgesic 2, 5
• Its opioid antagonist activity is one-fourth as potent as nalorphine and 10 times that of pentazocine 2
• May precipitate withdrawal in patients dependent on opioid drugs 2
• Should be used with caution in patients receiving mu opioid analgesics regularly 2

Endocrine Effects

• Chronic use may influence the hypothalamic-pituitary-gonadal axis 2
• May lead to androgen deficiency manifesting as low libido, impotence, erectile dysfunction, amenorrhea, or infertility 2

Use in Specific Conditions

• Can be used to treat opioid-induced pruritus that persists despite antihistamine treatment 1
• Lower abuse potential compared to pure opioid agonists 5, 3, 4