After a harrowing investigation, I've come to the conclusion that the poison in the huckleberry pie at the Shelbourne Restaurant & Bakery is the same compound being administered to me intravenously on a daily basis.
According to a white paper I found on arsenic trioxide, the compound has been used for therapeutic purposes for 2,400 years. In the fifteenth century, William Withering made the following argument supporting arsenic-based therapies: "Poisons in small doses are the best medicines; and the best medicines in too large doses are poisonous."
Since I haven't been able to find any references to what makes Trisenox different from a murder weapon, the only conclusion I can make is that it could have something to do with the dosage. Or a slight difference in the formulation that remains the drug company's trade secret.
During the 20th century the medicinal use of arsenic in the U.S. had declined, until the early 1990s when China reported its successful treatment of acute promyelocytic leukemia with the drug. In 2000, the FDA approved its use for APL in the United States.
According to Dr. Bayard Powell in an interview with The Cancer Channel, "We don’t know exactly how it works. It causes cell death. It works on the PML-RAR alpha complex, which is a result of a translocation between material on chromosomes 15 and 17 and that is the hallmark feature of acute promyelocytic leukemia and it attacks that complex and actually causes cell death and can also cause maturation of those cells. So, some of those cells may not even die, they may be rehabilitated or differentiated into normal cells."
In retrospect, the difference between arsenic trioxide as a poison and as a medicine is one mystery that's better left unsolved, at least by me. The only thing I should allow myself to think about with this medicine, and the forthcoming Daunorubicin, is that it's saving my life.