FDA and Novartis strengthened the labeling, including a new BOXED WARNING
and updates to the CONTRAINDICATIONS, WARNINGS, PRECAUTIONS, and CLINICAL
PHARMACOLOGY sections of the prescribing information for Cafergot.
Serious and/or life-threatening peripheral ischemia has been associated with
the coadministration of Cafergot with potent CYP 3A4 inhibitors including
protease inhibitors and macrolide antibiotics. Because CYP 3A4 inhibition
elevates the serum levels of Cafergot, the risk for vasospasm leading to
cerebral ischemia and/or ischemia of the extremities is increased. Because
of the increased risk of serious vasospastic adverse events, concomitant use
of these medications is contraindicated.