Nefazodone and Dihydroergotamine Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Nefazodone
No brand names on recordDihydroergotamine 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
Increased ergot derivatives exposure and an increased risk of ergotism (nausea, vomiting, vasospastic ischemia)
Interaction Deep Dive
The concurrent use of nefazodone (CYP3A4 inhibitor) and ergot derivatives is contraindicated due to the potential risk for serious toxicity including vasospasm. Pharmacokinetic interactions have been reported in patients treated orally with ergot alkaloids (eg, increased levels of ergotamine) and troleandomycin, presumably due to inhibition of CYP3A metabolism of the alkaloids by troleandomycin1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism by nefazodone
Literature reports
1 report — tap to read
a) Pharmacokinetic interactions have been reported in patients treated orally with ergot alkaloids (eg, increased levels of ergotamine) and troleandomycin, presumably due to inhibition of CYP3A metabolism of the alkaloids by troleandomycin 1.
Common questions
Can I take Nefazodone and Dihydroergotamine Injection together?
Increased ergot derivatives exposure and an increased risk of ergotism (nausea, vomiting, vasospastic ischemia) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nefazodone and Dihydroergotamine Injection interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Nefazodone or Dihydroergotamine 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: CAFERGOT(R) oral tablets, caffeine and ergotamine tartrate oral tablets. Novartis Pharmaceuticals Corporation, East Hanover, NJ, 2003. DailyMed
Keep reading about Nefazodone
Keep reading about Dihydroergotamine Injection
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