Methotrexate: Mechanism of Action, Diseases, and Pharmacology

This assignment provides a comprehensive overview of Methotrexate, a drug primarily used in the treatment of specific cancers and rheumatoid arthritis. The document details the drug's mechanism of action, focusing on its role as an antimetabolite that interferes with DNA synthesis by inhibiting enzymes responsible for nucleotide synthesis. It explains how Methotrexate, after entering tissues, is converted to methotrexate polyglutamate, affecting enzymes like thymidylate synthase and dihydrofolate reductase. The assignment also discusses the diseases treated by Methotrexate, including psoriasis, and the adverse effects associated with its use, such as mouth sores, anemia, nausea, and potential infertility. Furthermore, the document emphasizes the importance of understanding the drug's mechanism of action to comprehend its therapeutic benefits and potential risks. The information is supported by references to relevant research, including Drugbank (2020) and Inoue and Yuasa (2013).

Methotrexate is mainly used for the treatment of specific types of cancer and along with this,
sometimes rheumatoid arthritis is also treated with this drug when all other drugs remain
unresponsive to the disease condition. Moreover, it is reported that, this drug can also be
used to treat psoriasis. The action of this drug is exerted by slowing or stopping the growth
of cancer cells and suppression of immune system of the body (Drugbank 2020).
Methotrexate is one of the members of the antimetabolite drugs. Antimetabolite drug refers to
that drug that interferes with the action of one or more enzymes which are associated with the
process of DNA synthesis. This drug class of drugs affects the process DNA synthesis by
working as a substitute component to the original components. As a part of the antimetabolite
drugs, the functionality of methotrexate is discussed briefly (Drugbank 2020).
Functionality of Methotrexate
Hence, it can be concluded that the application of méthotrexate is associated
with the alteration of DNA synthesis process. However, it also works in various
other disease conditions such as rheumatoid arthristis , psoriasis. Its
mechanism of action is exerted by the inhibition process of the enzymes
responsible for nucleotides synthesis in the body. Therefore a few adverse
incidents are also reported by the researchers and they are mainly mouth
sores, anemia, easy bruising/bleeding, black stools, enlarged gland, unusual
pain, dry cough, muscle weakness.
Drugbank, 2020. Methotrexate. Drugbank. Retrieved from-
https://www.drugbank.ca/drugs/DB00563 [Accessed on- 6th March 2020]
Inoue, K. and Yuasa, H., 2013. Molecular basis for pharmacokinetics and
pharmacodynamics of methotrexate in rheumatoid arthritis therapy. Drug metabolism and
pharmacokinetics, pp.DMPK-13.
As a part of the adverse effect of this drug, it can be stated that cases of nausea, stomach,
drowsiness, vomiting are common. Along with this , cases of temporary hair loss, are also
reported. According to the data of Drugbank (2020), it is reported that the adverse incidents
may include mouth sores, anemia, easy bruising/bleeding, black stools, enlarged
gland, unusual pain, dry cough, muscle weakness. Moreover, cases of
infertility is also observed among males and females as well.
Introduction
Disease treatment
Adverse effects
References
Conclusion
While discussing about the mechanism of action of the drug named methotrexate it can be
stated that methotrexate enters into the tissues and then it is converted to a methotrexate
methotrexate polyglutamate by folylpolyglutamate. The mechanism of action of
methotrexate is associated with the inhibition process of the enzymes responsible for
nucleotides synthesis in the body (Drugbank 2020). This process of nucleotide synthesis
includes synthesis of enzymes such as thymidylate synthase, aminoimidazole caboxamide
ribonucleotide transformylase (AICART), dihydrofolate reductase and amido
phosphoribosyltransferase. Inhibition of the synthesis of this neucleotide prevents the
process of cell division. For example it can be mentioned that in case of rheumatoid
arthritis, methotrexate polyglutamates alters the action of AICART more than
methotrexate. This inhibition process leads to accumulation of AICRT ribonucleotide and
thereby causes accumulation of adenosine triphosphate and adenosine in the extracellular
space of the body. As a result, the adenosine receptors are stimulated and anti-
inflammatory action is observed. (Inoue and Yuasa 2013)
Mechanism of action