Tetracyclines Ergot derivatives

ERGOT DERIVATIVES TETRACYCLINES Cases of ergotism with tetracyclines and ergotamine Uncertain Avoid co-administration. If absolutely necessary, advise patients to discontinue treatment immediately if numbness and tingling of the extremities are felt... 

Information is very limited indeed. The incidence and general importance of this interaction is uncertain, but it would clearly be prudent to be on the alert for signs of ergotism in any patient given ergot derivatives and a tetracycline. However, note that one of the manufacturers of ergotamine actually recommends that the concurrent use of tetracycline should be avoided. Impairment of liver function may possibly be a contributory factor in this interaction. 

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