Interactions between d-h-e-45(dihydroergotamine) and Delavirdine (delavirdine)
dihydroergotamine and delavirdine (Major Drug-Drug)
CONTRAINDICATED: The coadministration with delavirdine may significantly increase the plasma concentrations of ergot derivatives. The mechanism is delavirdine inhibition of CYP450 3A4, the isoenzyme responsible for the metabolic clearance of ergotamine and related drugs. Although the interaction has not been specifically reported with delavirdine, clinical ergotism has occurred in patients receiving ergotamine or dihydroergotamine with other potent 3A4 inhibitors such as macrolide antibiotics and protease inhibitors.
MANAGEMENT: Given the potential for ergot toxicity characterized by peripheral vasospasm, ischemia, thrombosis, tachycardia and hypertension, concomitant use of ergot derivatives with delavirdine is considered contraindicated.
