Dihydroergotamine and nelfinavir
Desk tier: Avoid together
Mechanism: strong CYP3A4 inhibition of clearance (↑ exposure)
“The use of potent CYP3A4 inhibitors (i.e., ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) with dihydroergotamine is, therefore contraindicated”
Why this grade
Dihydroergotamine mesylate injection label, Contraindications
The Dihydroergotamine mesylate injection label lists this combination under Contraindications. CONTRAINDICATIONS: "The use of potent CYP3A4 inhibitors (i.e., ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) with dihydroergotamine is, therefore contraindicated" Named in the label: "nelfinavir" Retrieved from DailyMed 2026-10-12.
Dihydroergotamine mesylate injection label on DailyMedFDA interaction table
FDA's example-interaction table lists nelfinavir as a strong CYP3A inhibitor. FDA grades the roles; the severity tier on this row is the desk's rule. Table content current as of 2026-05-29.
FDA interaction tableAll pairs for Dihydroergotamine · nelfinavir
Enzyme behind this pair: CYP3A4
Educational reference only. Not FDA-cleared. The Prescribing Information governs.
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