Dihydroergotamine Injection and Cobicistat: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cobicistat
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
An increased risk of acute ergot toxicity (peripheral vasospasm, ischemia of the extremities)
Interaction Deep Dive
Concomitant administration of cobicistat with ergot derivatives is contraindicated due to potential for serious and/or life-threatening reactions such as acute ergot toxicity characterized by peripheral vasospasm and ischemia of the extremities and other tissues1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of ergot derivatives
Common questions
Can I take Dihydroergotamine Injection and Cobicistat together?
An increased risk of acute ergot toxicity (peripheral vasospasm, ischemia of the extremities) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dihydroergotamine Injection and Cobicistat 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Dihydroergotamine Injection or Cobicistat 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: SYMTUZA(R) oral tablets, darunavir, cobicistat, emtricitabine, tenofovir alafenamide oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2023. DailyMed
Keep reading about Cobicistat
Keep reading about Dihydroergotamine Injection
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