Among the several courses open to them to try to blunt the rejection mechanism, Washkansky's doctors chose to use two drugs, azathioprine (Imuran) and cortisone, plus radiation.
To counter this intolerance, the physicians on Barnard's team at Groote Schuur Hospital tried to suppress lymphocyte (and therefore antibody) production with drugs: azathioprine .
The drugs used, mainly azathioprine (Imuran) and prednisone, are so highly potent that by themselves they can seriously weaken or help to kill a patient.