Main Article on Poisoning Question: What have you been poisoned by? Submit Your Comment Comment from: Principal, 75 or over Male (Patient) Published: November 15 I have reacted to warfarin since the first day I have taken it; extreme tiredness, very short of breath, low blood, walking is difficult, etc. All tests have concentrated on blood loss somewhere in the body. All negative findings. REFERENCES: "Poisoning First Aid." RedCross. "Poisoning." U.S. National Library of Medicine. Updated Sept 21, 2016.