Erythromycin and Dihydroergotamine Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Erythromycin
Dihydroergotamine 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 dihydroergotamine exposure and an increased risk of acute ergot toxicity (ergotism)
Interaction Deep Dive
Coadministration of dihydroergotamine and strong CYP3A4 inhibitors, including certain macrolide antibiotics, is contraindicated due to the potential for acute ergot toxicity (ergotism) characterized by vasospasm and ischemia of the extremities1234 and other tissues including the central nervous system 5. Increased dihydroergotamine concentrations have been reported in patients treated with oral dihydroergotamine and certain macrolide antibiotics, presumably due to inhibition of CYP3A4-mediated metabolism of dihydroergotamine 4.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of dihydroergotamine
Literature reports
2 reports — tap to read
a) In patients treated orally with ergot alkaloids (eg, increased levels of ergotamine) and macrolide antibiotics, pharmacokinetic interactions have been reported, principally troleandomycin, presumably due to inhibition of CYP3A4 metabolism of the alkaloids by troleandomycin 4.
b) In a drug interaction study, coadministration of dihydroergotamine with itraconazole (CYP3A4 inhibitor) increased dihydroergotamine plasma exposure by 14% for Cmax and 19% for AUC while the plasma exposures (Cmax and AUC (0-inf)) of 8-beta-hydroxy dihydroergotamine (8-OH-DHE, active metabolite) were increased by approximately 4-fold and 3-fold, respectively 1.
Common questions
Can I take Erythromycin and Dihydroergotamine Injection together?
Increased dihydroergotamine exposure and an increased risk of acute ergot toxicity (ergotism) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Erythromycin 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 "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Erythromycin 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 (5)
- Product Information: ATZUMI(R) nasal powder, dihydroergotamine nasal powder. Satsuma Pharmaceuticals (per Manufacturer), Durham, NC, 2025. DailyMed
- Product Information: BREKIYA(R) subcutaneous injection, dihydroergotamine mesylate subcutaneous injection. Amneal Pharmaceuticals (Per Manufacturer), Bridgewater, NJ, 2025. DailyMed
- Product Information: TRUDHESA(TM) nasal spray, dihydroergotamine mesylate nasal spray. Impel NeuroPharma Inc (per DailyMed), Seattle, WA, 2021. DailyMed
- Product Information: Migranal(R) nasal spray, dihydroergotamine mesylate nasal spray. Bausch Health US LLC (per FDA), Bridgewater, NJ, 2022. DailyMed
- Product Information: BIAXIN(R) Granules oral suspension, clarithromycin oral suspension. AbbVie Inc (per FDA), North Chicago, IL, 2019. DailyMed
Keep reading about Erythromycin
Keep reading about Dihydroergotamine Injection
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