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Methotrexate, formerly known as amethopterin, is a
chemotherapy agent Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...
and immune-system suppressant. It is used to treat
cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...
,
autoimmune disease An autoimmune disease is a condition that results from an anomalous response of the adaptive immune system, wherein it mistakenly targets and attacks healthy, functioning parts of the body as if they were foreign organisms. It is estimated tha ...
s, and
ectopic pregnancies Ectopic pregnancy is a Complications of pregnancy, complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women ...
. Types of cancers it is used for include
breast cancer Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp ...
,
leukemia Leukemia ( also spelled leukaemia; pronounced ) is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or '' ...
,
lung cancer Lung cancer, also known as lung carcinoma, is a malignant tumor that begins in the lung. Lung cancer is caused by genetic damage to the DNA of cells in the airways, often caused by cigarette smoking or inhaling damaging chemicals. Damaged ...
,
lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). The name typically refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph node ...
, gestational trophoblastic disease, and
osteosarcoma An osteosarcoma (OS) or osteogenic sarcoma (OGS) is a cancerous tumor in a bone. Specifically, it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchyme, mesenchymal origin (and thus a sarcoma) and that exhi ...
. Types of autoimmune diseases it is used for include
psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small localized patches to complete b ...
,
rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects synovial joint, joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and h ...
, and
Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea, fever, abdominal distension, and weight loss. Complications outside of the ...
. It can be given
by mouth Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...
or by injection. Common side effects include nausea, feeling tired, fever, increased risk of infection, low white blood cell counts, and breakdown of the skin inside the mouth. Other side effects may include
liver disease Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common. Liver diseases File:Ground gla ...
,
lung disease The lungs are the primary organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the backbone on either side of the heart. Their function in the respiratory syst ...
, lymphoma, and severe skin rashes. People on long-term treatment should be regularly checked for side effects. It is not safe during
breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...
. In those with kidney problems, lower doses may be needed. It acts by blocking the body's use of
folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...
. Methotrexate was first made in 1947 and initially was used to treat cancer, as it was less toxic than the then-current treatments. In 1956 it provided the first cures of a metastatic cancer. It is on the
World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...
. Methotrexate is available as a
generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...
. In 2022, it was the 132nd most commonly prescribed medication in the United States, with more than 4million prescriptions.


Medical uses


Chemotherapy

Methotrexate was originally developed and continues to be used for
chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...
, either alone or in combination with other agents. It is effective for the treatment of several cancers, including solid tumours of breast, head and neck, lung, bladder, as well as acute lymphocytic leukemias, non-Hodgkin's lymphoma, osteosarcoma, and choriocarcinoma and other trophoblastic neoplasms. It is also used in the treatment of aggressive fibromatosis (desmoid tumor).


Autoimmune disorders

Although originally designed as a chemotherapy drug, in lower doses methotrexate is a generally safe and well-tolerated drug in the treatment of certain autoimmune diseases. Methotrexate is used as a disease-modifying treatment for several autoimmune diseases in adults, including rheumatoid arthritis,
psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small localized patches to complete b ...
and
psoriatic arthritis Psoriatic arthritis (PsA) is a long-term inflammatory arthritis that may occur in some people affected by the autoimmune disease psoriasis. The classic features of psoriatic arthritis include dactylitis (sausage-like swelling of the fingers ...
,
reactive arthritis Reactive arthritis, previously known as Reiter's syndrome, is a form of inflammatory arthritis that develops in response to an infection in another part of the body (cross-reactivity). Coming into contact with bacteria and developing an infect ...
, enteropathic arthritis, myositis,
systemic sclerosis Systemic scleroderma, or systemic sclerosis, is an autoimmune rheumatic disease characterised by excessive production and accumulation of collagen, called fibrosis, in the skin and internal organs and by injuries to small arteries. There are tw ...
,
lupus Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common ...
,
sarcoidosis Sarcoidosis (; also known as Besnier–Boeck–Schaumann disease) is a disease involving abnormal collections of White blood cell, inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph n ...
,
Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea, fever, abdominal distension, and weight loss. Complications outside of the ...
, and many forms of
vasculitis Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both artery, arteries and veins are affected. Lymphangitis (inflammation of lymphatic vessels) is sometimes considered a type of vasculitis. Vasculitis is primarily c ...
. In children, it can be used for juvenile dermatomyositis,
juvenile idiopathic arthritis Juvenile idiopathic arthritis (JIA), formerly known as juvenile rheumatoid arthritis (JRA), is the most common chronic rheumatic disease of childhood, affecting approximately 3.8 to 400 out of 100,000 children. ''Juvenile'', in this context, ref ...
,
uveitis Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and ...
and localised scleroderma. Methotrexate is one of the first-line therapies for the treatment of rheumatoid arthritis. Weekly doses of 5 to 25mg were found by a Cochrane review to be beneficial for 12–52 weeks duration of therapy, though it is used longer-term in clinical practice. Discontinuation rates are as high as 16% due to adverse effects. Use of low doses of methotrexate together with NSAIDs such as
aspirin Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...
or analgesics such as
paracetamol Paracetamol, or acetaminophen, is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is a widely available over-the-counter drug sold under various brand names, including Tylenol and Panadol. Parac ...
is relatively safe in people being treated for rheumatoid arthritis, with appropriate monitoring. Methotrexate is also sometimes used in combination with other conventional DMARDs, such as sulfasalazine and hydroxychloroquine. Studies and reviews have found that most rheumatoid arthritis patients treated with methotrexate for up to one year had less pain, functioned better, had fewer swollen and tender joints, and had less disease activity overall as reported by themselves and their doctors. X-rays also showed that the progress of the disease slowed or stopped in many people receiving methotrexate, with the progression being completely halted in about 30% of those receiving the drug. Those individuals with rheumatoid arthritis treated with methotrexate have been found to have a lower risk of cardiovascular events such as
myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom ...
s and
stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...
s. Results of a systematic review exploring the comparative effectiveness of treatments of early
rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects synovial joint, joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and h ...
show that treatment efficacy can be improved with combination therapy with anti-TNF or other biologic medications, compared with methotrexate monotherapy. Likewise, a 2016 study found the use of methotrexate, in combination with anti-TNF agents, is effective for the treatment of
ulcerative colitis Ulcerative colitis (UC) is one of the two types of inflammatory bowel disease (IBD), with the other type being Crohn's disease. It is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary sympto ...
. Methotrexate has also been used for
multiple sclerosis Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...
and is used occasionally in
systemic lupus erythematosus Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common ...
, with tentative evidence to support such use.


Atopic dermatitis

Along with other immunosuppressants, methotrexate is used to treat severe
atopic dermatitis Atopic dermatitis (AD), also known as atopic eczema, is a long-term type of inflammation of the skin. Atopic dermatitis is also often called simply eczema but the same term is also used to refer to dermatitis, the larger group of skin conditi ...
(eczema).


During pregnancy

Methotrexate is an
abortifacient An abortifacient ("that which will cause a miscarriage" from Latin: '' abortus'' "miscarriage" and '' faciens'' "making") is a substance that induces abortion. This is a nonspecific term which may refer to any number of substances or medications, ...
and is used to treat
ectopic pregnancies Ectopic pregnancy is a Complications of pregnancy, complication of pregnancy in which the embryo attaches outside the uterus. Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women ...
, provided the
fallopian tube The fallopian tubes, also known as uterine tubes, oviducts or salpinges (: salpinx), are paired tubular sex organs in the human female body that stretch from the Ovary, ovaries to the uterus. The fallopian tubes are part of the female reproduct ...
has not ruptured. Methotrexate with
dilation and curettage Dilation (or dilatation) may refer to: Physiology or medicine * Cervical dilation, the widening of the cervix in childbirth, miscarriage etc. * Coronary dilation, or coronary reflex * Dilation and curettage, the opening of the cervix and s ...
is used to treat molar pregnancy. Rarely, it is used in combination with
misoprostol Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. It is taken by mouth when used ...
to abort intrauterine pregnancies.


Administration

Methotrexate can be given by mouth or by injection (
intramuscular Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...
,
intravenous Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutr ...
, subcutaneous, or intrathecal). Doses are usually taken weekly, not daily, to limit toxicity. Routine monitoring of the
complete blood count A complete blood count (CBC), also known as a full blood count (FBC) or full haemogram (FHG), is a set of medical laboratory tests that provide cytometry, information about the cells in a person's blood. The CBC indicates the counts of white blo ...
,
liver function tests Liver function tests (LFTs or LFs), also referred to as a hepatic panel or liver panel, are groups of blood tests that provide information about the state of a patient's liver. These tests include prothrombin time (PT/INR), activated partial ...
, and
creatinine Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass). Biological relevance Serum creatinine (a blood measurement) is an impor ...
are recommended. Measurements of creatinine are recommended at least every two months.
Folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...
is commonly co-prescribed with methotrexate to minimise the risk of adverse effects.


Adverse effects

The most common adverse effects include
hepatotoxicity Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury (DILI) is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdr ...
, stomatitis, blood abnormalities (
leukopenia Leukopenia () is a decrease in the number of white blood cells (leukocytes). It places individuals at increased risk of infection as white blood cells are the body's primary defense against infections. Signs and symptoms Symptoms may include: * s ...
,
anaemia Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin availab ...
and
thrombocytopenia In hematology, thrombocytopenia is a condition characterized by abnormally low levels of platelets (also known as thrombocytes) in the blood. Low levels of platelets in turn may lead to prolonged or excessive bleeding. It is the most common coag ...
), increased risk of infection, hair loss, nausea, reduced appetite, abdominal pain, diarrhea, fatigue, fever, dizziness, drowsiness, headache, acute
pneumonitis Pneumonitis describes general inflammation of lung tissue. Possible causative agents include radiation therapy of the chest, exposure to medications used during chemo-therapy, the inhalation of debris (e.g., animal dander), aspiration, herbicide ...
and renal impairment. Methotrexate can also cause mucositis. Methotrexate pneumonitis is a rare complication of therapy and appears to be reducing in frequency in most recent rheumatoid arthritis treatment trials. In the context of rheumatoid arthritis
interstitial lung disease Interstitial lung disease (ILD), or diffuse parenchymal lung disease (DPLD), is a group of respiratory diseases affecting the interstitium (the tissue) and space around the alveoli (air sacs) of the lungs. It concerns alveolar epithelium, pulm ...
, methotrexate treatment may be associated with a lower incidence of ILD over time. Methotrexate is
teratogenic Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology caused by ...
and it is advised to stop taking it at least 4 weeks before becoming pregnant and it should be avoided during pregnancy ( pregnancy category X) and while breastfeeding. Guidelines have been updated to state that it is safe for a male partner to take at any point while trying to conceive. Central nervous system reactions to methotrexate have been reported, especially when given via the intrathecal route (directly into the
cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ...
), which include myelopathies and leukoencephalopathies. It has a variety of cutaneous side effects, particularly when administered in high doses. Another little-understood but serious possible adverse effect of methotrexate is neurological damage and memory loss. Neurotoxicity may result from the drug crossing the
blood–brain barrier The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...
and damaging neurons in the cerebral cortex. People with cancer who receive the medication often nickname these effects " chemo brain" or "chemo fog".


Drug interactions

Penicillins Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by '' P. chrysogenum'' ...
may decrease the elimination of methotrexate and increase the risk of methotrexate toxicity. While they may be used together, increased monitoring is recommended. The
aminoglycoside Aminoglycoside is a medicinal and bacteriologic category of traditional Gram-negative antibacterial medications that inhibit protein synthesis and contain as a portion of the molecule an amino-modified glycoside (sugar). The term can also refer ...
s
neomycin Neomycin, also known as framycetin, is an aminoglycoside antibiotic that displays bactericidal activity against Gram-negative aerobic bacilli and some anaerobic bacilli where resistance has not yet arisen. It is generally not effective against ...
and paromomycin have been found to reduce gastrointestinal (GI) absorption of methotrexate.
Probenecid Probenecid, also sold under the brand name Probalan, is a medication that increases uric acid excretion in the urine. It is primarily used in treating gout and hyperuricemia. Probenecid was developed as an alternative to caronamide to competitive ...
inhibits methotrexate excretion, which increases the risk of methotrexate toxicity. Likewise,
retinoid The retinoids are a class of chemical compounds that are natural derivatives of vitamin A or are chemically related to it. Synthetic retinoids are utilized in cosmetic formulations, clinical dermatology, and the treatment of some forms of cancer ...
s and trimethoprim have been known to interact with methotrexate to produce additive hepatotoxicity and haematotoxicity, respectively. Other immunosuppressants like cyclosporins may potentiate methotrexate's haematologic effects, hence potentially leading to toxicity. NSAIDs have also been found to fatally interact with methotrexate in numerous case reports.
Nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or factitious air, among others, is a chemical compound, an Nitrogen oxide, oxide of nitrogen with the Chemical formula, formula . At room te ...
potentiating the haematological toxicity of methotrexate has also been documented. Proton-pump inhibitors such as omeprazole and the
anticonvulsant Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatme ...
valproate Valproate (valproic acid, VPA, sodium valproate, and valproate semisodium forms) are medications primarily used to treat epilepsy and bipolar disorder and prevent migraine headaches. They are useful for the prevention of seizures in those with ...
have been found to increase the plasma concentrations of methotrexate, as have nephrotoxic agents such as
cisplatin Cisplatin is a chemical compound with chemical formula, formula ''cis''-. It is a coordination complex of platinum that is used as a chemotherapy medication used to treat a number of cancers. These include testicular cancer, ovarian cancer, c ...
, the GI drug colestyramine, and
dantrolene Dantrolene sodium, sold under the brand name Dantrium among others, is a postsynaptic muscle relaxant that lessens excitation-contraction coupling in muscle cells. It achieves this by inhibiting Ca2+ ions release from sarcoplasmic reticul ...
.


Vaccine interactions

Taking methotrexate can reduce the effectiveness of vaccinations against various diseases, such as
influenza Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These sympto ...
and
hepatitis A Hepatitis A is an infectious liver disease caused by Hepatitis A virus (HAV); it is a type of viral hepatitis. Many cases have few or no symptoms, especially in the young. The time between infection and symptoms, in those who develop them, is ...
. It does this by blunting the
immune response An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellula ...
of the body to the vaccine. Methotrexate also dampens the immune response to
COVID-19 vaccines A COVID19 vaccine is a vaccine intended to provide acquired immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 ( COVID19). Knowledge about the structure and func ...
, making them less effective. Pausing methotrexate for two weeks following COVID-19 vaccination may result in improved immunity. Not taking the medicine for two weeks might result in a minor increase of inflammatory disease flares in some people.


Mechanism of action

Methotrexate is an antimetabolite of the antifolate type. It is thought to affect cancer and rheumatoid arthritis by two different pathways. For cancer, methotrexate competitively inhibits dihydrofolate reductase (DHFR), an
enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that participates in the tetrahydrofolate synthesis. The affinity of methotrexate for DHFR is about 1000-fold that of dihydrofolate. DHFR catalyses the conversion of dihydrofolate to the active tetrahydrofolate. Tetrahydrofolate is needed for the ''de novo'' synthesis of the
nucleoside Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotid ...
thymidine Thymidine (nucleoside#List of nucleosides and corresponding nucleobases, symbol dT or dThd), also known as deoxythymidine, deoxyribosylthymine, or thymine deoxyriboside, is a pyrimidine nucleoside, deoxynucleoside. Deoxythymidine is the DNA nuc ...
, required for DNA synthesis. Also, folate is essential for de-novo
purine Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted puri ...
base biosynthesis, so synthesis will be inhibited. Methotrexate, therefore, inhibits the synthesis of
DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
,
RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...
, thymidylates, and
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
s. For the treatment of rheumatoid arthritis, inhibition of DHFR is not thought to be the main mechanism, but rather multiple mechanisms appear to be involved, including the inhibition of enzymes involved in purine metabolism, leading to accumulation of
adenosine Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9- glycosidic bond. Adenosine is one of the four nucleoside build ...
; inhibition of
T cell T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell ...
activation and suppression of
intercellular adhesion molecule In molecular biology, intercellular adhesion molecules (ICAMs) and vascular cell adhesion molecule-1 (VCAM-1) are part of the immunoglobulin superfamily. They are important in inflammation, immune responses and in intracellular signalling event ...
expression by T cells; selective down-regulation of
B cell B cells, also known as B lymphocytes, are a type of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or inserted into the plasm ...
s; increasing
CD95 The Fas receptor, also known as Fas, FasR, apoptosis antigen 1 (APO-1 or APT), cluster of differentiation 95 (CD95) or tumor necrosis factor receptor superfamily member 6 (TNFRSF6), is a protein that in humans is encoded by the ''FAS'' gene. Fas ...
sensitivity of activated T cells; and inhibition of methyltransferase activity, leading to deactivation of enzyme activity relevant to immune system function. Another mechanism of MTX is the inhibition of the binding of interleukin 1-beta to its cell surface receptor. Thereby, it acts as anticytokine.


History

In 1947, a team of researchers led by Sidney Farber showed aminopterin, a chemical analogue of
folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...
developed by Yellapragada Subbarao of Lederle, could induce remission in children with
acute lymphoblastic leukemia Acute lymphoblastic leukemia (ALL) is a cancer of the Lymphocyte, lymphoid line of blood cells characterized by the development of large numbers of lymphoblast, immature lymphocytes. Symptoms may include feeling tired, pale skin color, fever, ...
. The development of folic acid analogues had been prompted by the discovery that the administration of folic acid worsened leukaemia, and that a diet deficient in folic acid could, conversely, produce improvement; the
mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...
behind these effects was still unknown at the time. Other analogues of folic acid were in development, and by 1950, methotrexate (then known as amethopterin) was being proposed as a treatment for leukemia. Animal studies published in 1956 showed the
therapeutic index The therapeutic index (TI; also referred to as therapeutic ratio) is a quantitative measurement of the relative safety of a drug with regard to risk of overdose. It is a comparison of the amount of a therapeutic agent that causes toxicity to the ...
of methotrexate was better than that of aminopterin, and clinical use of aminopterin was thus abandoned in favor of methotrexate. In 1951, Jane C. Wright demonstrated the use of methotrexate in solid tumors, showing remission in breast cancer. Wright's group was the first to demonstrate use of the drug in solid tumors, as opposed to leukemias, which are a cancer of the marrow. Min Chiu Li and his collaborators then demonstrated complete remission in women with choriocarcinoma and chorioadenoma in 1956, and in 1960 Wright et al. produced remissions in mycosis fungoides.


References


External links


Methotrexate Injection
MedlinePlus article from NIH {{Authority control Antifolates Antineoplastic and immunomodulating drugs Benzamides Chemotherapy Disease-modifying antirheumatic drugs Folates Hepatotoxins IARC Group 3 carcinogens Immunosuppressants Mammalian dihydrofolate reductase inhibitors Medication abortion Abortifacients Nephrotoxins Orphan drugs Wikipedia medicine articles ready to translate World Health Organization essential medicines