Causes 2 Symptoms 2.1 Convulsive symptoms 2.2 Gangrenous symptoms 3 History 4 Salem Witchcraft Accusations 5 References 6 External links [ edit ] Causes The toxic ergoline derivatives are found in ergot-based drugs (such as methylergometrine , ergotamine or, previously, ergotoxine ). The deleterious side-effects occur either under high dose or