Nalbuphine

Pronunciation: nal-BYOO-feen.

Generic name
nalbuphine hydrochloride
Brand names
Nubain (historical, US/Canada/UK/EU)
Drug class
Opioid agonist-antagonist analgesic (kappa-receptor agonist, mu-receptor antagonist)
Form
Injection solution, 10 mg/mL and 20 mg/mL
Route
Injection (subcutaneous, intramuscular, or intravenous)
Legal status
Prescription-only, controlled substance (scheduled as an opioid)

Availability and supply rules vary by country

Trade names by country: United States · Canada

Australia: · Full directory

What nalbuphine hydrochloride is and how it works

Nalbuphine is an injectable opioid pain medicine used in hospital and clinical settings for moderate to severe pain, and for pain relief during and after surgery and during labor. It works differently from typical opioids: it activates one type of opioid receptor (kappa) while blocking another (mu). (1)

Because nalbuphine partly blocks the mu opioid receptor, it can trigger sudden withdrawal symptoms in someone who is physically dependent on a full opioid agonist (such as morphine, oxycodone, or fentanyl) -- this is an important difference from typical opioid painkillers that your care team will take into account. Like other opioids, it carries real risks of serious breathing problems, dependence, and dangerous interactions with sedatives or alcohol, so it is given and monitored by trained clinical staff.

Mechanism of action: how nalbuphine hydrochloride works

Nalbuphine is a synthetic opioid agonist-antagonist of the phenanthrene series, acting as an agonist at kappa opioid receptors (providing analgesia) and as an antagonist at mu opioid receptors (blocking typical full-agonist opioid effects at that receptor and capable of precipitating withdrawal in mu-agonist-dependent patients). (1)

What nalbuphine hydrochloride is used for

Moderate to severe pain

Used for the management of moderate to severe pain in situations where an opioid analgesic is appropriate and alternative treatments are inadequate. (1)

Perioperative and obstetric analgesia

Used for preoperative and postoperative pain relief, as a supplement to surgical anesthesia, and for pain relief during labor. (1)

Before taking nalbuphine hydrochloride

Do not take / not appropriate for

  • Nalbuphine should not be given if you have significant respiratory depression without resuscitation equipment and monitoring available. (all countries) (1)
  • Nalbuphine should not be given during an acute or severe asthma attack unless in a monitored setting with resuscitation equipment available. (all countries) (1)
  • Nalbuphine should not be given if you have a known or suspected bowel obstruction, including paralytic ileus. (all countries) (1)
  • Do not use nalbuphine if you have had an allergic reaction to it. (all countries) (1)

Tell your clinician about

  • Whether you regularly take a full opioid agonist (such as morphine, oxycodone, methadone, or fentanyl), since nalbuphine can precipitate withdrawal in someone physically dependent on these medicines.
  • Any history of opioid use disorder, misuse, or addiction.
  • Any breathing problems, asthma, or lung disease.
  • Any head injury or condition causing raised pressure inside the skull.
  • All other medicines you take, especially benzodiazepines, sedatives, or other CNS depressants.
  • Whether you are pregnant, in labor, or breastfeeding.
(1)

How to take nalbuphine hydrochloride

  • Nalbuphine is given by injection (under the skin, into a muscle, or into a vein) by a trained clinician, in a monitored healthcare setting.
  • Your dose and dosing interval are individually determined by your clinical team based on your weight, pain severity, and response -- there is no fixed dose for everyone.
  • A typical adult starting dose described in the label is 10 mg for a 70 kg person, repeated every 3 to 6 hours as needed, with a usual single dose not exceeding 20 mg and a maximum total daily dose of 160 mg, but your own regimen is set individually by your clinical team.
  • If you have been receiving nalbuphine regularly, any change in dose, frequency, or stopping treatment is managed by your clinical team, who may taper the dose gradually to reduce the chance of withdrawal symptoms.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4)

Missed dose

Nalbuphine is given by a clinician in a monitored setting, so dosing timing and any missed dose is managed directly by your clinical team according to your ongoing pain assessment.

Overdose

Nalbuphine overdose is a medical emergency. Signs can include severe drowsiness, slowed or stopped breathing, pinpoint pupils, and loss of consciousness. This is managed immediately by the clinical team with emergency measures, which may include an opioid antagonist and respiratory support. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Sedation is the most frequently reported side effect.

What to notice: Sedation is the most frequently reported side effect.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Sweating (diaphoresis).

What to notice: Sweating (diaphoresis).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Nausea and vomiting.

What to notice: Nausea and vomiting.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Dizziness, dry mouth, and headache.

What to notice: Dizziness, dry mouth, and headache.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of serious breathing problems (respiratory depression) — boxed_warning

Symptoms: Slow, shallow, or stopped breathing; extreme drowsiness; unresponsiveness.

Action: This is a medical emergency requiring immediate clinical intervention. Risk is highest when nalbuphine treatment is started or the dose is increased, and clinical staff monitor closely, especially in the first 24 to 72 hours. (1)

Signs of opioid withdrawal in a patient dependent on a full opioid agonist — high caution

Symptoms: Agitation, sweating, goosebumps, nausea, vomiting, diarrhea, muscle aches, or a racing heartbeat appearing soon after a nalbuphine dose.

Action: Because of nalbuphine's mu-receptor-blocking action, it can precipitate acute withdrawal in someone physically dependent on a full opioid agonist. Tell your clinical team immediately about any recent or regular use of other opioid medicines so this can be anticipated and managed. (1)

Signs of profound sedation when combined with other CNS depressants — emergency

Symptoms: Extreme drowsiness, confusion, slowed breathing, or unresponsiveness, particularly if benzodiazepines, other sedatives, or alcohol have also been used.

Action: Seek immediate medical attention; this combination carries a serious risk of profound sedation, respiratory depression, coma, and death. (1)

Signs of serotonin syndrome (with serotonergic drugs) — emergency

Symptoms: Agitation, rapid heartbeat, high body temperature, muscle rigidity, or loss of coordination.

Action: Seek immediate medical attention if these symptoms occur, particularly if other serotonergic medicines are also being used. (1)

Interactions

  • Benzodiazepines and other CNS depressants (including alcohol) significantly increase the risk of profound sedation, respiratory depression, coma, and death when combined with nalbuphine. (1)
  • Serotonergic drugs combined with nalbuphine carry a risk of serotonin syndrome. (1)
  • MAO inhibitors are contraindicated with nalbuphine because of toxicity and serotonin syndrome risk. (1)
  • Nalbuphine can enhance the effect of muscle relaxants used during anesthesia. (1)
  • Nalbuphine given to a patient who regularly takes a full opioid agonist can precipitate withdrawal because of its mu-receptor-blocking activity. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Nalbuphine is used during labor for obstetric analgesia, but severe fetal bradycardia (slow heart rate) has been reported with its use during labor. Newborns exposed near the time of delivery are monitored for respiratory depression, apnea, low muscle tone, and slow heart rate or arrhythmias. (1) (2) (3) (4)

Breastfeeding

Nalbuphine passes into breast milk in small amounts (less than 1% of the maternal dose). Breastfed infants should be monitored for sedation and slowed breathing. (1) (2) (3) (4)

Children

Use in children is individually determined by a clinician based on weight and clinical need; not addressed with a standard fixed pediatric regimen in the source reviewed. (1) (2) (3) (4)

Elderly

Older or debilitated patients may be more sensitive to nalbuphine's sedative and respiratory effects and require closer monitoring. (1) (2) (3) (4)

Hepatic_impairment

Tell your clinical team about any liver problems, as this can affect how nalbuphine is processed. (1) (2) (3) (4)

Renal_impairment

Tell your clinical team about any kidney problems, as dosing may need adjustment. (1) (2) (3) (4)

Monitoring

Before starting

  • Assessment of current opioid use/dependence status
  • Baseline respiratory status
  • Screening for risk of misuse or addiction

During treatment

  • Continuous or frequent monitoring of breathing and sedation level, especially in the first 24-72 hours or after a dose increase.
  • Ongoing reassessment of pain control and side effects.
  • Watching for signs of opioid withdrawal or of misuse, abuse, or addiction.
  • Gradual, clinician-directed dose tapering rather than abrupt discontinuation after prolonged use, to reduce the chance of withdrawal symptoms.
(1)

Storage

Stored and handled by clinical staff according to the product label, protected from light, at controlled room temperature, as a controlled substance with appropriate security.

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information; verify against the current full label before prescribing.

United States

Indication: Moderate to severe pain; perioperative/obstetric analgesia

Dose summary: 10 mg (for a 70 kg adult) subcutaneously, intramuscularly, or intravenously, repeated every 3-6 hours as needed; usual single dose not to exceed 20 mg; maximum total daily dose 160 mg; individualised and titrated to the lowest effective dose.

Renal context: Not established as a specific fixed adjustment in the source reviewed; individualised regardless. (1)

Mechanism of action

Hepatic guidance

Hepatic impairment can alter nalbuphine metabolism; monitor closely and adjust dosing individually.

Overdose note

Manage suspected overdose as an emergency with respiratory support and consideration of an opioid antagonist; contact a poison control service for guidance. (1)

Frequently asked questions

Is nalbuphine available in the US, UK, Europe, and Canada?

Yes, nalbuphine hydrochloride injection is available in the US, UK, European Union (nationally authorised in member states), and Canada. Its current marketing status in Australia and New Zealand could not be confirmed and is being checked directly with those countries' regulators. (1) (2) (3) (4)

Why might nalbuphine cause withdrawal symptoms in someone already taking opioids?

Nalbuphine partly blocks the mu opioid receptor, the same receptor that full opioid agonists (like morphine or oxycodone) depend on for their effect. In a person who is physically dependent on a full agonist, this blocking action can suddenly displace the usual opioid effect and trigger withdrawal symptoms -- this is why clinical teams ask about current opioid use before giving nalbuphine. (1)

Is nalbuphine as risky for breathing problems as other opioids?

It carries real risks -- nalbuphine can cause life-threatening respiratory depression, especially when starting treatment or after a dose increase, and this risk is greater when combined with benzodiazepines, alcohol, or other sedating medicines. Unlike some full opioid agonists, nalbuphine has a 'ceiling effect' where doses above 30 mg do not cause further respiratory depression on their own, but this protection disappears if other sedating drugs are also on board. (1)

What is the mechanism of action of nalbuphine hydrochloride?

Nalbuphine is a synthetic opioid agonist-antagonist of the phenanthrene series, acting as an agonist at kappa opioid receptors (providing analgesia) and as an antagonist at mu opioid receptors (blocking typical full-agonist opioid effects at that receptor and capable of precipitating withdrawal in mu-agonist-dependent patients). (1)

What is the generic name of Nalbuphine?

The generic name is nalbuphine hydrochloride. It is sold under brand names including Nubain (historical, US/Canada/UK/EU). (1)

What class of drug is nalbuphine hydrochloride?

Nalbuphine is classed as: Opioid agonist-antagonist analgesic (kappa-receptor agonist, mu-receptor antagonist). (1)

References

  1. NALBUPHINE HYDROCHLORIDE injection -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information · United States · accessed 2026-07-29 · source 1
  2. Nalbuphine -- list of nationally authorised medicinal products (PSUSA/00002110/202305)European Medicines Agency (EMA) -- Periodic Safety Update Report Single Assessment (PSUSA) for nationally authorised products · European Union · accessed 2026-07-29 · source 2
  3. Nalbuphine hydrochloride injection -- UK-licensed parenteral analgesicUnited Kingdom medicines regulation (MHRA) via national product licensing; Nubain/generic nalbuphine injection · United Kingdom · accessed 2026-07-29 · source 3
  4. NUBAIN (Nalbuphine Hydrochloride) Injection, 10 and 20 mg/mL -- Product MonographHealth Canada product monograph · Canada · accessed 2026-07-29 · source 4

Brand names by country

Single-ingredient nalbuphine hydrochloride names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • NALBUPHINE HCI10 mg/mL, 20 mg/mL · hf acquisition co llc, dba healthfirst

Canada

  • NUBAIN
View brands in additional countries.

This page provides general reference information about nalbuphine and is not a substitute for advice from the clinical team administering your treatment. All dosing and treatment decisions are made by your clinical team.

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