Alfentanil and Nalbuphine Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Alfentanil
No brand names on recordNalbuphine Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of CNS depression, profound sedation, respiratory depression, hypotension, coma and death, reduced analgesic effect or precipitation of withdrawal symptoms, and an increased risk of serotonin syndrome
Interaction Deep Dive
Avoid concomitant use of ALfentanil with a serotonergic CNS-mixed opioid agonist/antagonist or a partial agonist opioid analgesic as this may reduce the analgesic effect of ALfentanil and may precipitate withdrawal symptoms may also result in profound sedation, respiratory depression, coma, and/or death. Additionally, observe the patient carefully when using ALfentanil concomitantly with other drugs that affect the serotonergic system, especially during initiation and titration, as risk for serotonin syndrome is increased; discontinue if suspected. Reserve concomitant use to clinical settings where alternative treatment options are inadequate. If combination therapy is required, reduce the initial dose of the newly prescribed medication and titrate to clinical response while monitoring for respiratory depression and sedation. Vasodilation and hypotension caused by concomitant use may delay recovery. If hypotension occurs consider hypovolemia as a cause and manage with parenteral fluids. Consider repositioning the patient to improve venous return to the heart, however, use caution moving the patient due to risk of orthostatic hypotension. If hypotension is not adequately corrected with fluids, consider pressor agents other than EPINEPHrine. Following ALfentanil administration, reduce the dose of other CNS depressants. If the decision is made to manage postoperative pain with ALfentanil concomitantly with or other CNS depressant, start dosing with the lowest effective dosage and titrate based on clinical response. Fluids or other measures to counter hypotension should be available1.
Why it happens (mechanism)
Additive CNS depression; opioid receptor antagonism; additive serotonergic effects
Common questions
Can I take Alfentanil and Nalbuphine Injection together?
An increased risk of CNS depression, profound sedation, respiratory depression, hypotension, coma and death, reduced analgesic effect or precipitation of withdrawal symptoms, and an increased risk of serotonin syndrome Always confirm with your pharmacist or prescriber before making any change.
How serious is the Alfentanil and Nalbuphine Injection interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Alfentanil or Nalbuphine Injection need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: Alfentanil HCl intravenous injection, alfentanil HCl intravenous injection. Rising Pharma Holdings, Inc (per FDA), East Brunswick, NJ, 2025.
Keep reading about Alfentanil
Keep reading about Nalbuphine Injection
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