Acute upper extremity ischemia during concomitant use of ergotamine tartrate and ampicillin.

Individual hypersensitivity to the vasoconstrictor effects of ergotamine tartrate has been observed even at doses within recommended limits. Hypersensitivity can be induced by concomitant use with other drugs. The best-documented example of drug-induced hypersensitivity to ergotamine tartrate involves antibiotics of the macrolides class. The mechanism underlying this interaction appears to be interference with metabolism of ergotamine tartrate by the liver. In the present report we describe a case of upper extremity ischemia during concomitant use of ergotamine tartrate and ampicillin. The fact that the effect was not dose-dependent, disappeared when administration of ampicillin was discontinued, and reappeared when administration of ampicillin was resumed suggests that the underlying mechanism in our patient was immunologic. Since immunologic hypersensitivity to the vasoconstrictor effects of ergotamine tartrate is unpredictable, great caution and close surveillance is advisable when ergotamine tartrate is used in association with other drugs.