Mycophenolate is an immunosuppressive drug that is often used in conjunction with other medicines such as cyclosporine or corticoids in organ transplants. It is a complex chemical compound that interferes with nucleic acid metabolism.
As mycophenolate mofetil, the drug was developed by the American pharmaceutical company Synthex. It was launched in the US under the name CellCept® in 1995. It was one of the first drugs to be approved in Europe through a centralized 15-country approval process. As a chemical compound it is present as an almost white crystalline powder. It is insoluble in water. However, it dissolves a little in absolute alcohol. The melting point of the active ingredient is 93 to 94 degrees Celsius.
Mycophenolate mofetil is a so-called prodrug. It is converted in the organism into the active substance mycophenolic acid. In commerce this active substance is also available as sodium salt under the trade name Myfortic®. In this form, the drug represents a water-soluble drug. Also, the sodium salt is converted in the body into the active form mycophenolic acid.
Mycophenolic acid (MPA) is an active substance that inhibits the enzyme inosine monophosphate dehydrogenase (IMPDH). Inosine monophosphate dehydrogenase is responsible for the synthesis of guanosine. Guanosine is in turn a basic building block of the nucleic acids DNA and RNA. It contains the important purine base guanine.
Due to the inhibition of IMPDH also guanosine is no longer synthesized. All processes that are dependent on nucleic acid formation are also suppressed. However, the inhibition of the enzyme is selective and reversible. So no other enzymes are inhibited and after discontinuation of the drug, the synthesis of guanosine takes place immediately again.
However, the selectivity also means that, in contrast to other immunosuppressive agents, the production of B and T lymphocytes is inhibited and selectively increased. The immune cells, like no other cells, rely on the re-synthesis of purine nucleotides because they proliferate and their needs can not be adequately met by the disintegration of old cells.
However, this new synthesis of purine bases, especially guanosine, is completely out of the question here. Other body cells that do not multiply so strongly also have the opportunity to use reprocessed purine bases from the breakdown of old nucleic acids. However, the immune system is largely dependent on the availability of sufficient nucleic acid, as it must form a variety of immune cells. Thus, constantly new T lymphocytes, B lymphocytes, natural killer cells or macrophages must be present in order to ensure adequate immune protection for the organism.
However, these cells are also formed to perform rejection reactions after organ transplantation. In this case, the immune system should be suppressed. However, the efficacy of mycophenolate is so strong that in fact it should only be used after organ transplants. Because the side effects are so serious that the use would have rather adverse consequences, for example in autoimmune diseases.
The main application of mycophenolate, as already mentioned, is the use in organ transplants. It is mainly used in kidney, liver or heart transplants. However, mycophenolate is always used with ciclosporin and corticosteroids to suppress the immune system.
The medication begins two days after transplantation by oral tablets. The effect is selective. Unlike some other immunosuppressants, the metabolite mycophenolic acid is not incorporated into the DNA. Only the new synthesis of purine bases is suppressed. This leads to a normal immune response immediately after stopping the medication. The effect of mycophenolate is very strong. However, the drug can suppress the rejection reactions very well.
This potent immunosuppressive effect of mycophenolate, on the other hand, causes severe side effects. The side effects are often severe and occur in large numbers. Common side effects include anemia, thrombocytopenia, nausea, vomiting, and diarrhea. The anemia is caused by the inhibition of blood formation due to the lack of nucleic acid synthesis.
In addition, the immunosuppressive treatment of common infections such as herpes simplex, herpes zoster, candidiasis or even sepsis is accompanied. Malformations have even been reported in newborn infants whose mothers have been treated with mycophenolate in combination with other immunosuppressants.
In a few cases, life-threatening progressive multifocal leukoencephalopathy (PML) is also associated. PML is an infection of the central nervous system with polyomaviruses, which can only be given to persons with a high degree of immunodeficiency. The disease progresses rapidly and leads to numerous neurological deficits, which can eventually be fatal. Furthermore, as with the other immunosuppressants, there is also the possibility of developing skin cancer. Therefore, it is important not to expose yourself to UV rays during the treatment. Tags: