kill or cure
Either remedy a disease or kill the patient, as in The copy chief did not like her headline for the drug, “Kill or Cure.” This expression dates from the mid-1700s, when it was already being used half-jokingly.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
Examples from the Web for kill or cure
Foxglove, for instance, from which digitalis used as a medicine is extracted, is a good example of these kill-or-cure plants.The Naturalist on the Thames
C. J. Cornish