Every year August 13 is observed as World Organ Donation Day to raising awareness about the importance of organ donation. Process in the United States
Organ donors are usually dead at the time of donation, but may be living. For living donors, organ donation typically involves extensive testing before the donation, including psychological evaluation to determine whether the would-be donor understands and consents to the donation. On the day of the donation, the donor and the recipient arrive at the hospital, just like they would for any other major surgery.For dead donors, the process begins with verifying that the person is undoubtedly deceased, determining whether any organs could be donated, and obtaining consent for the donation of any usable organs. Normally, nothing is done until the person has already died, although if death is inevitable, it is possible to check for consent and to do some simple medical tests shortly beforehand, to help find a matching recipient.The verification of death is normally done by a neurologist (a physician specializing in brain function) that is not involved in the previous attempts to save the patients life. This physician has nothing to do with the transplantation process. Verification of death is often done multiple times, to prevent doctors from overlooking any remaining sign of life, however small. After death, the hospital may keep the body on a mechanical ventilator and use other methods to keep the organs in good condition. The donors estate and their families are not charged for any expenses related to the donation.
Drug interactions
Allopurinol inhibits xanthine oxidase, the enzyme that breaks down mercaptopurine. Those taking allopurinol (often used to prevent gout) are at risk for mercaptopurine toxicity. The dose should be reduced or allopurinol should be discontinued. Several published studies have demonstrated that the use of allopurinol in combination with low dose 6-MP helps reduce 6-MP levels, which are toxic to liver tissue, whilst increasing the therapeutic levels of 6-MP for some inflammatory conditions. Mechanisms of action
Official information from the package insert for purinethol:
Mercaptopurine is an antimetabolite antineoplastic, as such it interferes with normal metabolic processes within cells, typically by combining with enzymes, to disrupt DNA and RNA synthesis (cell-cycle S phase-specific) leading to death of rapidly proliferating cells, especially malignant ones. Specifically, Mercaptopurine is a purine antimetabolite or purine antagonist as such inhibits DNA synthesis by inhibiting the production of the purine containing nucleotides, adenine and guanine thus halting DNA synthesis. Mercaptopurine also acts as an immunomodulator by inhibiting of several pathways in nucleic acid biosynthesis preventing proliferation of cells involved in the determination and amplification of the immune response. Mercaptopurine (6-MP) competes with the purine derivatives hypoxanthine and guanine for the enzyme HGPRT and is itself converted to thio inosine monophosphate (TIMP). TIMP inhibits several chemical reactions involving inosinic acid (IMP), including the conversion of IMP to xanthylic acid (XMP) and the conversion of IMP to adenylic acid (AMP) via adenylosuccinate (SAMP). In addition, 6-methylthioinosinate (MTIMP) is formed by the methylation of TIMP.