Dihydroergotamine and Mifepristone interaction

WARNING: PERIPHERAL ISCHEMIA FOLLOWING COADMINISTRATION WITH POTENT CYP3A4 INHIBITORS Serious and/or life-threatening peripheral ischemia has been associated with the coadministration of dihydroergotamine with potent CYP3A4 inhibitors including protease inhibitors and macrolide antibiotics.

Because CYP3A4 inhibition elevates the serum levels of dihydroergotamine, the risk for vasospasm leading to cerebral ischemia and/or ischemia of the extremities is increased.

CONTRAINDICATIONS There have been a few reports of serious adverse events associated with the coadministration of dihydroergotamine and potent CYP3A4 inhibitors, such as protease inhibitors and macrolide antibiotics, resulting in vasospasm that led to cerebral ischemia and/or ischemia of the extremities.

The use of potent CYP3A4 inhibitors (i.e., ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) with dihydroergotamine is, therefore, contraindicated (see WARNINGS, CYP3A4 Inhibitors ).

The use of potent CYP3A4 inhibitors with dihydroergotamine should therefore be avoided (see CONTRAINDICATIONS ).

…Specific Populations ( 8.1 , 8.3 )] Patients taking drugs metabolized by CYP3A such as simvastatin, lovastatin, and CYP3A substrates with narrow therapeutic ranges, such as cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus, due to an increased risk of adverse events. [See Drug Interactions ( 7.1 ) and Clinical Pharmacology…

…the increased risk of myopathy and rhabdomyolysis. [See Contraindications (4.2), Clinical Pharmacology 12.3 ] The exposure of other substrates of CYP3A with narrow therapeutic ranges, such as cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus, may be increased by concomitant administration with mifepristone.