You're doing lab medicine and get the two blood smears shown above. Your attending tells the team to order a historically important test. The team gives the patient 2mcg oral radio-labeled drug A and 1000 mcg intramuscular non-labeled A. Urine is collected and the excretion of radio-labeled A is low (<8% of the administered dose).
The team then repeats this test but also gives oral drug B along with the oral drug A, followed by the intramuscular non-labeled A. The urine collection now shows normal excretion of the radio-labeled molecule A (8-35%).
Challenge: What is the diagnosis and how is the coin shown above related?
First image is in the public domain (photoshopped by me), second and third images shown under Fair Use.