Treating medieval plague: the wonderful virtues of theriac.

This paper examines one of the most popular remedies in medieval plague medicine, namely theriac, and explores possible reasons for its remarkable continuity in the late medieval and early modern medical tradition. Theriac, reputed as a universal antidote since ancient times, was a complex compound, composed of multiple ingredients, difficult to prepare, and subject to strict manufacturing and commercial controls. The paper centers on the therapeutic applications of theriac and on its relative pharmacologic efficacy in treating the symptoms of plague. The consistent use of theriac in plague medicine attests not only to the conservatism of medieval medical practice, but also to an underlying solidly founded rationale that combined humoral doctrine, empiric observation, and pharmacologic effect.