Please note: Any medical or genetic information present in this entry is not intended as a diagnosis of your problem, but rather is provided as a helpful guide for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Information is not necessarily complete. Please see your doctor for diagnosis and treatment.

Please note: DNAtraffic database is the project under construction and information on this page is not finished yet.

Mycophenolic acid


ACCESSION NB: DB01024 (APRD01603, EXPT02208)


TYPE: small molecule


GROUP: approved


DESCRIPTION:
Mycophenolic acid is an an immunosuppresant drug and potent anti-proliferative, and can be used in place of the older anti-proliferative azathioprine. It is usually used as part of triple therapy including a calcineurin inhibitor (ciclosporin or tacrolimus) and prednisolone. It is also useful in research for the selection of animal cells that express the E. coli gene coding for XGPRT (xanthine guanine phosphoribosyltransferase).

VOLUME OF DISTRIBUTION: 54 ± 25 L

CATEGORIES:
Enzyme Inhibitors Antibiotics, Antineoplastic

ABSORPTION: Bioavailability following oral administration of Myfortic delayed-release tablet ranges from 70-95%

INDICATION:
For the prophylaxis of organ rejection in patients receiving allogeneic renal transplants, administered in combination with cyclosporine and corticosteroids.

PHARMACODYNAMICS:
Mycophenolic acid is an antibiotic substance derived from Penicillium stoloniferum. It blocks de novo biosynthesis of purine nucleotides by inhibition of the enzyme inosine monophosphate dehydrogenase. Mycophenolic acid is important because of its selective effects on the immune system. It prevents the proliferation of T-cells, lymphocytes, and the formation of antibodies from B-cells. It also may inhibit recruitment of leukocytes to inflammatory sites.

MECHANISM OF ACTION:
Mycophenolic acid is a potent, selective, uncompetitive, and reversible inhibitor of inosine monophosphate dehydrogenase (IMPDH), and therefore inhibits the de novo pathway of guanosine nucleotide synthesis without incorporation into DNA. Because T- and B-lymphocytes are critically dependent for their proliferation on de novo synthesis of purines, whereas other cell types can utilize salvage pathways, mycophenolic acid has potent cytostatic effects on lymphocytes. Mycophenolic acid inhibits proliferative responses of T- and B-lymphocytes to both mitogenic and allospecific stimulation. Addition of guanosine or deoxyguanosine reverses the cytostatic effects of mycophenolic acid on lymphocytes. Mycophenolic acid also suppresses antibody formation by B-lymphocytes. Mycophenolic acid prevents the glycosylation of lymphocyte and monocyte glycoproteins that are involved in intercellular adhesion to endothelial cells and may inhibit recruitment of leukocytes into sites of inflammation and graft rejection.

PROTEIN BINDING:
>98%

METABOLISM:
Mycophenolic acid is metabolized mainly by glucuronyl transferase to glucuronidated metabolites, predominantly the phenolic glucuronide, mycophenolic acid glucuronide (MPAG). MPAG does not manifest pharmacological activity. The acyl glucuronide minor metabolite has pharmacological activity similar to mycophenolic acid. The AUC ratio of Mycophenolic acid:MPAG:acyl glucuronide is approximately 1:24:0.28 at steady state.

TOXICITY:
Oral (LD50): Acute: 352 mg/kg [Rat], 1000 mg/kg [Mouse], and >6000 mg/kg [Rabbit]. Possible signs and symptoms of acute overdose could include the following: hematological abnormalities such as leukopenia and neutropenia, and gastrointestinal symptoms such as abdominal pain, diarrhea, nausea and vomiting, and dyspepsia.

AFECTED ORGANISMS:
Humans and other mammals