Had excruciating headaches with sensitivity to light and chills with no slurred speech or weakness or drooping of face. mri confirmed an ischemic stroke in vision center of the brain. Lost left peripheral vision in both eyes. Could this have been caused by azathioprine? Blood tests would clump together in the vials when drawn and after sending out to a different lab Dr. Had me stop taking this drug as it was becoming toxic in my bloodstream.