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2D Structure
Also known as: 59-05-2, Amethopterin, Rheumatrex, Methylaminopterin, Abitrexate, Trexall
Molecular Formula
C20H22N8O5
Molecular Weight
454.4  g/mol
InChI Key
FBOZXECLQNJBKD-ZDUSSCGKSA-N
FDA UNII
YL5FZ2Y5U1

An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.
Methotrexate is a Folate Analog Metabolic Inhibitor. The mechanism of action of methotrexate is as a Folic Acid Metabolism Inhibitor.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
(2S)-2-[[4-[(2,4-diaminopteridin-6-yl)methyl-methylamino]benzoyl]amino]pentanedioic acid
2.1.2 InChI
InChI=1S/C20H22N8O5/c1-28(9-11-8-23-17-15(24-11)16(21)26-20(22)27-17)12-4-2-10(3-5-12)18(31)25-13(19(32)33)6-7-14(29)30/h2-5,8,13H,6-7,9H2,1H3,(H,25,31)(H,29,30)(H,32,33)(H4,21,22,23,26,27)/t13-/m0/s1
2.1.3 InChI Key
FBOZXECLQNJBKD-ZDUSSCGKSA-N
2.1.4 Canonical SMILES
CN(CC1=CN=C2C(=N1)C(=NC(=N2)N)N)C3=CC=C(C=C3)C(=O)NC(CCC(=O)O)C(=O)O
2.1.5 Isomeric SMILES
CN(CC1=CN=C2C(=N1)C(=NC(=N2)N)N)C3=CC=C(C=C3)C(=O)N[C@@H](CCC(=O)O)C(=O)O
2.2 Other Identifiers
2.2.1 UNII
YL5FZ2Y5U1
2.3 Synonyms
2.3.1 MeSH Synonyms

1. Amethopterin

2. Dicesium Salt Methotrexate

3. Hydrate, Methotrexate

4. Methotrexate Hydrate

5. Methotrexate Sodium

6. Methotrexate, (d)-isomer

7. Methotrexate, (dl)-isomer

8. Methotrexate, Dicesium Salt

9. Methotrexate, Disodium Salt

10. Methotrexate, Sodium Salt

11. Mexate

12. Sodium, Methotrexate

2.3.2 Depositor-Supplied Synonyms

1. 59-05-2

2. Amethopterin

3. Rheumatrex

4. Methylaminopterin

5. Abitrexate

6. Trexall

7. Mexate

8. Metatrexan

9. Hdmtx

10. Methylaminopterinum

11. Mtx

12. (s)-2-(4-(((2,4-diaminopteridin-6-yl)methyl)(methyl)amino)benzamido)pentanedioic Acid

13. Methotrexatum

14. Rasuvo

15. 4-amino-10-methylfolic Acid

16. Metotrexato

17. Maxtrex

18. Nsc-740

19. Mexate-aq

20. N-bismethylpteroylglutamic Acid

21. Folex

22. Nci-c04671

23. Cl-14377

24. Antifolan

25. Methotrexate Lpf

26. Xatmep

27. 133073-73-1

28. Amethopterine

29. Farmitrexat

30. Emt 25,299

31. L-amethopterin

32. Cl 14377

33. Methotrexat-ebewe

34. Tcmdc-125858

35. (2s)-2-[[4-[(2,4-diaminopteridin-6-yl)methyl-methylamino]benzoyl]amino]pentanedioic Acid

36. Abitrexate (methotrexate)

37. R 9985

38. Yl5fz2y5u1

39. Methotextrate

40. Methotrexat

41. Chembl34259

42. Nsc740

43. Chebi:44185

44. Adx-2191

45. N-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-l-glutamic Acid

46. N-[(4-{[(2,4-diaminopteridin-6-yl)methyl](methyl)amino}phenyl)carbonyl]-l-glutamic Acid

47. Cl14377

48. Ncgc00025060-04

49. Nsc 740

50. 4-amino-n(10)-methylpteroylglutamic Acid

51. A-methopterin

52. Dsstox_cid_822

53. A-methpterin

54. Amethopterin L-

55. Folex-pfs

56. R-9985

57. (2s)-2-[(4-{[(2,4-diaminopteridin-6-yl)methyl](methyl)amino}phenyl)formamido]pentanedioic Acid

58. Dsstox_rid_75810

59. Methotrexate, L-

60. Dsstox_gsid_20822

61. X 133

62. Metotressato [dcit]

63. Methotrexate, D-

64. Fauldexato

65. Medsatrexate

66. Methoblastin

67. Metotressato

68. Brimexate

69. Emthexat

70. Emthexate

71. Lantarel

72. Lumexon

73. Metrotex

74. Novatrex

75. Otrexup

76. Tremetex

77. Trexeron

78. Trixilem

79. Metex

80. Texate

81. Mls001401431

82. Methotrexatum [inn-latin]

83. Metotrexato [inn-spanish]

84. [3h]methotrexate

85. Smr000112001

86. [3h]-methotrexate

87. Folic Acid Antagonist

88. Ccris 1109

89. 4-aminomethylpteroylglutamic Acid

90. Hsdb 3123

91. L-(+)-n-(p-(((2,4-diamino-6-pteridinyl)methyl)methylamino)benzoyl)glutamic Acid

92. N-(p-(((2,4-diamino-6-pteridinyl)methyl)methylamino)benzoyl)-l-(+)-glutamic Acid

93. Sr-01000075682

94. Smr000449324

95. Einecs 200-413-8

96. Unii-yl5fz2y5u1

97. Metolate

98. Nordimet

99. Ai3-25299

100. Intradose-mtx

101. 4-amino-n(sup 10)-methylpteroylglutamic Acid

102. 1dhi

103. 1dhj

104. 2drc

105. 4ocx

106. (2s)-2-[[4-[(2,4-diaminopteridin-6-yl)methyl-methyl-amino]benzoyl]amino]pentanedioic Acid

107. Cas-59-05-2

108. Glutamic Acid, N-(p-(((2,4-diamino-6-pteridinyl)methyl)methylamino)benzoyl)-, L-

109. Kyselina N-(p-((2,4-diamino-6-pteridinylmethyl)methylamino)benzoyl)-l-glutamova

110. Mpi-2505

111. Prestwick_322

112. Otrexup (tn)

113. Xatmep (tn)

114. Reditrex

115. Kyselina 4-amino-n(sup 10)-methylpteroylglutamova [czech]

116. Methylaminopterin; Mtx

117. Methotrexate [usan:usp:inn:ban:jan]

118. Spectrum_001836

119. Tocris-1230

120. 4kn0

121. Wr-19039

122. Prestwick0_000135

123. Prestwick1_000135

124. Prestwick2_000135

125. Spectrum2_001077

126. Spectrum3_000497

127. Spectrum4_000616

128. Spectrum5_000958

129. Methotrexate - Abitrexate

130. Methotrexate [mi]

131. N-(p-(((2,4-diamino-6-pteridyl)methyl)methylamino)benzoyl)glutamic Acid

132. Methotrexate [inn]

133. Methotrexate [jan]

134. L(+)-amethopterin Hydrate

135. Methotrexate [hsdb]

136. Methotrexate [iarc]

137. Methotrexate [inci]

138. Methotrexate [usan]

139. N-(4-(((2,4-diamino-6-pteridinyl)methyl)methylamino)benzoyl)-l-glutamicacid

140. Ncimech_000767

141. Schembl3711

142. Kyselina N-(p-((2,4-diamino-6-pteridinylmethyl)methylamino)benzoyl)-l-glutamova [czech]

143. Methotrexate [vandf]

144. Bidd:pxr0175

145. Lopac0_000020

146. Kbiogr_001172

147. Kbioss_002341

148. Methotrexate [mart.]

149. Kyselina 4-amino-n(sup 10)-methylpteroylglutamova

150. Mls000049968

151. Mls002154208

152. Divk1c_000114

153. Methotrexate [usp-rs]

154. Methotrexate [who-dd]

155. Methotrexate [who-ip]

156. Spbio_001094

157. Spbio_002149

158. Amy235

159. Cid_126941

160. Cid_165528

161. Gtpl4674

162. Gtpl4815

163. Dtxsid4020822

164. Schembl12421860

165. Schembl23111732

166. Bdbm18050

167. Bdbm66082

168. Hms500f16

169. Kbio1_000114

170. Kbio2_002338

171. Kbio2_004906

172. Kbio2_007474

173. Kbio3_001493

174. Methotrexate (jp17/usp/inn)

175. G301

176. Ninds_000114

177. Bio1_000486

178. Bio1_000975

179. Bio1_001464

180. Hms1568k12

181. Hms2095k12

182. Hms2233o18

183. Hms3260c21

184. Hms3414l09

185. Hms3678l07

186. Hms3712k12

187. Methotrexate [orange Book]

188. Methotrexate [ep Monograph]

189. Methotrexate [usp Impurity]

190. Act03341

191. Apc-2002

192. Bcp13701

193. Mpi-5004

194. Zinc1529323

195. Methotrexate [usp Monograph]

196. Tox21_110944

197. Tox21_300269

198. Tox21_500020

199. Ccg-35800

200. Emt-25299

201. Methotrexatum [who-ip Latin]

202. Mfcd00064370

203. S1210

204. Stl535338

205. (4-(((2,4-diaminopteridin-6-yl)methyl)(methyl)amino)benzoyl)-l-glutamic Acid

206. Akos016340329

207. Tox21_110944_1

208. Cs-1732

209. Db00563

210. Ks-5093

211. Lp00020

212. Sdccgsbi-0050009.p003

213. Wr19039

214. Idi1_000114

215. N-(4-{[(2,4-diaminopteridin-6-yl)methyl](methyl)amino}benzoyl)-l-glutamic Acid

216. Smp2_000020

217. (methyl)amino)benzamido)pentanedioic Acid

218. Ncgc00025060-01

219. Ncgc00025060-02

220. Ncgc00025060-03

221. Ncgc00025060-05

222. Ncgc00025060-06

223. Ncgc00025060-07

224. Ncgc00025060-08

225. Ncgc00025060-09

226. Ncgc00025060-10

227. Ncgc00025060-11

228. Ncgc00025060-12

229. Ncgc00025060-13

230. Ncgc00025060-15

231. Ncgc00025060-16

232. Ncgc00254216-01

233. Ncgc00260705-01

234. Hy-14519

235. Eu-0100020

236. G-301

237. Sw198601-3

238. Methotrexate 1.0 Mg/ml In Dimethyl Sulfoxide

239. 73m731

240. A10021

241. C01937

242. D00142

243. Q422232

244. Sr-01000597411

245. W-60383

246. (s)-2-(4-(((2,4-diaminopteridin-6-yl)methyl)

247. Q-201366

248. Sr-01000075682-1

249. Sr-01000075682-2

250. Sr-01000075682-6

251. Sr-01000597411-1

252. W-105347

253. Brd-k59456551-001-09-3

254. Brd-k59456551-001-11-9

255. Wln: T66 Bn Dn Gn Jnj Cz Ez H1n1&r Dvmyvq2vq

256. Z1541638527

257. N,n,n,n-ethylenediaminetetra(methylenephosphonicacid)

258. Methotrexate, European Pharmacopoeia (ep) Reference Standard

259. Methotrexate, United States Pharmacopeia (usp) Reference Standard

260. Glutamic Acid,4-diamino-6-pteridinyl)methyl] Methylamino]benzoyl]-, L-(+)-

261. L-glutamic Acid,4-diamino-6-pteridinyl)methyl]- Methylamino]benzoyl]-

262. (s)-2-(4-(((2,4-diaminopteridin-6-yl)methyl)-(methyl)amino)benzamido)pentanedioic Acid

263. L-glutamic Acid,n-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-,hydrate(9ci)

264. Methotrexate For Peak Identification, European Pharmacopoeia (ep) Reference Standard

265. Methotrexate For System Suitability, European Pharmacopoeia (ep) Reference Standard

266. Methotrexate, Pharmaceutical Secondary Standard; Certified Reference Material

267. N-[4-[[(2,4-diamino-6-pteridinyl)methyl] Methylamino]benzoyl]-l-glutamic Acid

268. (2s)-2-((4-(((2,4-diaminopteridin-6-yl)methyl)(methyl)amino)benzoyl)amino)pentanedioic Acid

269. (2s)-2-[[[4-[(2,4-diamino-6-pteridinyl)methyl-methylamino]phenyl]-oxomethyl]amino]pentanedioic Acid;hydrate

270. (2s)-2-[[4-[(2,4-diaminopteridin-6-yl)methyl-methyl-amino]benzoyl]amino]glutaric Acid;hydrate

271. (2s)-2-[[4-[[2,4-bis(azanyl)pteridin-6-yl]methyl-methyl-amino]phenyl]carbonylamino]pentanedioic Acid;hydrate

272. 102613-64-9

273. L-glutamic Acid,n-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-, Hydrate (9ci)

274. Methotrexate, Pharmagrade, Manufactured Under Appropriate Controls For Use As A Raw Material In Pharma Or Biopharmaceutical Production, Meets Ep, Usp Testing Specifications

2.4 Create Date
2005-06-24
3 Chemical and Physical Properties
Molecular Weight 454.4 g/mol
Molecular Formula C20H22N8O5
XLogP3-1.8
Hydrogen Bond Donor Count5
Hydrogen Bond Acceptor Count12
Rotatable Bond Count9
Exact Mass454.17131583 g/mol
Monoisotopic Mass454.17131583 g/mol
Topological Polar Surface Area211 Ų
Heavy Atom Count33
Formal Charge0
Complexity704
Isotope Atom Count0
Defined Atom Stereocenter Count1
Undefined Atom Stereocenter Count0
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently Bonded Unit Count1
4 Drug and Medication Information
4.1 Drug Information
1 of 4  
Drug NameMethotrexate sodium
Drug LabelMethotrexate (formerly Amethopterin) is an antimetabolite used in the treatment of certain neoplastic diseases, severe psoriasis, and adult rheumatoid arthritis. Chemically methotrexate is N-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-...
Active IngredientMethotrexate sodium
Dosage FormTablet; Injectable
RouteInjection; Oral
Strengtheq 200mg base/8ml (eq 25mg base/ml); eq 250mg base/10ml (eq 25mg base/ml); eq 50mg base/2ml (eq 25mg base/ml); eq 2.5mg base; eq 100mg base/4ml (eq 25mg base/ml)
Market StatusPrescription
CompanyHospira; Roxane; Dava Pharms; Fresenius Kabi Usa; Eurohlth Intl; Mylan; Barr

2 of 4  
Drug NameTrexall
PubMed HealthMethotrexate
Drug ClassesAntineoplastic Agent, Antipsoriatic, Antirheumatic, Antirheumatic, Cytotoxic
Drug LabelTrexall (methotrexate tablets USP) (formerly Amethopterin) is an antimetabolite used in the treatment of certain neoplastic diseases, severe psoriasis, and adult rheumatoid arthritis. Chemically methotrexate, USP is N-[4[[(2,4-diamino-6-pteridiny...
Active IngredientMethotrexate sodium
Dosage FormTablet
RouteOral
Strengtheq 5mg base; eq 7.5mg base; eq 15mg base; eq 10mg base
Market StatusPrescription
CompanyBarr

3 of 4  
Drug NameMethotrexate sodium
Drug LabelMethotrexate (formerly Amethopterin) is an antimetabolite used in the treatment of certain neoplastic diseases, severe psoriasis, and adult rheumatoid arthritis. Chemically methotrexate is N-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-...
Active IngredientMethotrexate sodium
Dosage FormTablet; Injectable
RouteInjection; Oral
Strengtheq 200mg base/8ml (eq 25mg base/ml); eq 250mg base/10ml (eq 25mg base/ml); eq 50mg base/2ml (eq 25mg base/ml); eq 2.5mg base; eq 100mg base/4ml (eq 25mg base/ml)
Market StatusPrescription
CompanyHospira; Roxane; Dava Pharms; Fresenius Kabi Usa; Eurohlth Intl; Mylan; Barr

4 of 4  
Drug NameTrexall
PubMed HealthMethotrexate
Drug ClassesAntineoplastic Agent, Antipsoriatic, Antirheumatic, Antirheumatic, Cytotoxic
Drug LabelTrexall (methotrexate tablets USP) (formerly Amethopterin) is an antimetabolite used in the treatment of certain neoplastic diseases, severe psoriasis, and adult rheumatoid arthritis. Chemically methotrexate, USP is N-[4[[(2,4-diamino-6-pteridiny...
Active IngredientMethotrexate sodium
Dosage FormTablet
RouteOral
Strengtheq 5mg base; eq 7.5mg base; eq 15mg base; eq 10mg base
Market StatusPrescription
CompanyBarr

4.2 Therapeutic Uses

Abortifacient Agents, Nonsteroidal; Antimetabolites, Antineoplastic; Antirheumatic Agents; Dermatologic Agents; Enzyme Inhibitors; Folic Acid Antagonists; Immunosuppressive Agents; Nucleic Acid Synthesis Inhibitors

National Library of Medicine's Medical Subject Headings online file (MeSH, 1999)


Methotrexate is indicated for treatment of breast carcinoma, head and neck cancers (epidermoid), non-small cell lung carcinoma (especially squamous cell types), small cell lung carcinoma, and gestational trophoblastic tumors (gestational choriocarcinoma, chorioadenoma destruens, hydatidiform mole). /Included in US product labeling/

Thomson.Micromedex. Drug Information for the Health Care Professional. 24th ed. Volume 1. Plus Updates. Content Reviewed by the United States Pharmacopeial Convention, Inc. Greenwood Village, CO. 2004., p. 1911


Methotrexate is indicated for treatment of cervical carcinoma, ovarian carcinoma, bladder carcinoma, colorectal carcinoma, esophageal carcinoma, gastric carcinoma, pancreatic carcinoma, and penile carcinoma. /NOT included in US product labeling/

Thomson.Micromedex. Drug Information for the Health Care Professional. 24th ed. Volume 1. Plus Updates. Content Reviewed by the United States Pharmacopeial Convention, Inc. Greenwood Village, CO. 2004., p. 1911


Methotrexate is indicated for treatment of acute lymphocytic leukemia and prophylaxis and treatment of meningeal leukemia. /Included in US product labeling/

Thomson.Micromedex. Drug Information for the Health Care Professional. 24th ed. Volume 1. Plus Updates. Content Reviewed by the United States Pharmacopeial Convention, Inc. Greenwood Village, CO. 2004., p. 1911


For more Therapeutic Uses (Complete) data for METHOTREXATE (17 total), please visit the HSDB record page.


4.3 Drug Warning

Methotrexate is a highly toxic drug with a very low therapeutic index and a therapeutic response is not likely to occur without some evidence of toxicity. ... When methotrexate is used in combination with other antineoplastic agents and/or radiation therapy, toxic reactions may be more severe than would occur with methotrexate therapy alone. Although doses of methotrexate used in the management of psoriasis and rheumatoid arthritis are usually lower than those used in antineoplastic chemotherapy, severe toxicity may occur in any patient receiving the drug and deaths have been reported with the use of methotrexate in the management of psoriasis and rheumatoid arthritis.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1111


Methotrexate should be used with extreme caution in patients with infection, peptic ulcer, ulcerative colitis, or debility, and in very young or geriatric patients. Methotrexate should be used with extreme caution, if at all, in patients with malignant disease who have preexisting liver damage or impaired hepatic function, preexisting bone marrow depression, aplasia, leukopenia, thrombocytopenia, or anemia; the drug is usually contraindicated in patients with impaired renal function. In the management of psoriasis, methotrexate is contraindicated in patients with poor nutritional status or severe renal or hepatic disorders, those with overt or laboratory evidence of an immunodeficiency syndrome, and in those with preexisting blood dyscrasias such as bone marrow hypoplasia, leukopenia, thrombocytopenia, or clinically important anemia; relative contraindications also include cirrhosis, active or recent hepatitis, or excessive alcohol consumption. In the management of rheumatoid arthritis, methotrexate is contraindicated in patients with preexisting blood dyscrasias such as bone marrow hypoplasia, leukopenia, thrombocytopenia, or clinically important anemia; those with overt or laboratory evidence of immunodeficiency syndromes; and those with excessive alcohol consumption, alcoholic liver disease, or chronic liver disease.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1112


Elevations in serum uric acid concentrations may occur in patients receiving methotrexate as a result of cell destruction and hepatic and renal damage. In some patients, uric acid nephropathy and acute renal failure may result. Tumor lysis syndrome associated with other cytotoxic drugs (e.g., fludarabine, cladribine), also has been reported in patients with rapidly growing tumors who were receiving methotrexate. Pharmacologic and appropriate supportive treatment may prevent or alleviate this complication. Methotrexate also was reported to precipitate acute gouty arthritis in two patients being treated for psoriasis. Administration of large volumes of fluids, alkalinization of the urine, and/or administration of allopurinol may be useful in preventing acute attacks of hyperuricemia and uric acid nephropathy.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1111


Severe nephropathy manifested by azotemia, hematuria, and renal failure may occur in patients receiving methotrexate; fatalities have been reported. In one study, postmortem examination revealed extensive necrosis of the epithelium of the convoluted tubules. In patients with renal impairment, methotrexate accumulation and increased toxicity or additional renal damage may occur.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1111


For more Drug Warnings (Complete) data for METHOTREXATE (22 total), please visit the HSDB record page.


4.4 Drug Indication

Methotrexate oral solution is indicated for pediatric acute lymphoblastic leukemia and pediatric polyarticular juvenile idiopathic arthritis. Methotrexate injections for subcutaneous use are indicated for severe active rheumatoid arthritis, polyarticular juvenile idiopathic arthritis and severe, recalcitrant, disabling psoriasis. Other formulations are indicated to treat gestational choriocarcinoma, chorioadenoma destruens, hydatiform mole, breast cancer, epidermoid cancer of the head and neck, advanced mycosis fungoides, lung cancer, and advanced non-Hodgkin's lymphoma. It is also used in the maintenance of acute lymphocytic leukemia. Methotrexate is also given before treatment with leucovorin to prolong relapse-free survival following surgical removal of a tumour in non-metastatic osteosarcoma.


FDA Label


Nordimet is indicated for the treatment of:

- active rheumatoid arthritis in adult patients,

- polyarthritic forms of severe, active juvenile idiopathic arthritis (JIA), when the response to nonsteroidal anti-inflammatory drugs (NSAIDs) has been inadequate,

- severe recalcitrant disabling psoriasis, which is not adequately responsive to other forms of therapy such as phototherapy, psoralens and ultraviolet A (PUVA), and retinoids, and severe psoriatic arthritis in adult patients,

- induction of remission in moderate steroid-dependent Crohn's disease in adult patients, in combination with corticosteroids and for maintenance of remission, as monotherapy, in patients who have responded to methotrexate.


5 Pharmacology and Biochemistry
5.1 Pharmacology

Methotrexate inhibits enzymes responsible for nucleotide synthesis which prevents cell division and leads to anti-inflammatory actions. It has a long duration of action and is generally given to patients once weekly. Methotrexate has a narrow therapeutic index. Do not take methotrexate daily.


5.2 MeSH Pharmacological Classification

Abortifacient Agents, Nonsteroidal

Non-steroidal chemical compounds with abortifacient activity. (See all compounds classified as Abortifacient Agents, Nonsteroidal.)


Enzyme Inhibitors

Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction. (See all compounds classified as Enzyme Inhibitors.)


Antimetabolites, Antineoplastic

Antimetabolites that are useful in cancer chemotherapy. (See all compounds classified as Antimetabolites, Antineoplastic.)


Immunosuppressive Agents

Agents that suppress immune function by one of several mechanisms of action. Classical cytotoxic immunosuppressants act by inhibiting DNA synthesis. Others may act through activation of T-CELLS or by inhibiting the activation of HELPER CELLS. While immunosuppression has been brought about in the past primarily to prevent rejection of transplanted organs, new applications involving mediation of the effects of INTERLEUKINS and other CYTOKINES are emerging. (See all compounds classified as Immunosuppressive Agents.)


Antirheumatic Agents

Drugs that are used to treat RHEUMATOID ARTHRITIS. (See all compounds classified as Antirheumatic Agents.)


Dermatologic Agents

Drugs used to treat or prevent skin disorders or for the routine care of skin. (See all compounds classified as Dermatologic Agents.)


Folic Acid Antagonists

Inhibitors of the enzyme, dihydrofolate reductase (TETRAHYDROFOLATE DEHYDROGENASE), which converts dihydrofolate (FH2) to tetrahydrofolate (FH4). They are frequently used in cancer chemotherapy. (From AMA, Drug Evaluations Annual, 1994, p2033) (See all compounds classified as Folic Acid Antagonists.)


Nucleic Acid Synthesis Inhibitors

Compounds that inhibit cell production of DNA or RNA. (See all compounds classified as Nucleic Acid Synthesis Inhibitors.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
METHOTREXATE
5.3.2 FDA UNII
YL5FZ2Y5U1
5.3.3 Pharmacological Classes
Copper-containing Intrauterine Device [EPC]; Decreased Embryonic Implantation [PE]; Decreased Sperm Motility [PE]; Inhibit Ovum Fertilization [PE]; Copper [CS]
5.4 ATC Code

L04AX03


L04AX03

S76 | LUXPHARMA | Pharmaceuticals Marketed in Luxembourg | Pharmaceuticals marketed in Luxembourg, as published by d'Gesondheetskeess (CNS, la caisse nationale de sante, www.cns.lu), mapped by name to structures using CompTox by R. Singh et al. (in prep.). List downloaded from https://cns.public.lu/en/legislations/textes-coordonnes/liste-med-comm.html. Dataset DOI:10.5281/zenodo.4587355


L - Antineoplastic and immunomodulating agents

L01 - Antineoplastic agents

L01B - Antimetabolites

L01BA - Folic acid analogues

L01BA01 - Methotrexate


L - Antineoplastic and immunomodulating agents

L04 - Immunosuppressants

L04A - Immunosuppressants

L04AX - Other immunosuppressants

L04AX03 - Methotrexate


5.5 Absorption, Distribution and Excretion

Absorption

Methotrexate has a bioavailability of 64-90%, though this decreases at oral doses above 25mg due to saturation of the carrier mediated transport of methotrexate.. Methotrexate has a Tmax of 1 to 2 hours. oral doses of 10-15g reach serum levels of 0.01-0.1M.


Route of Elimination

Methotrexate is >80% excreted as the unchanged drug and approximately 3% as the 7-hydroxylated metabolite. Methotrexate is primarily excreted in the urine with 8.7-26% of an intravenous dose appearing in the bile.


Volume of Distribution

The volume of distribution of methotrexate at steady state is approximately 1L/kg.


Clearance

Methotrexate clearance varies widely between patients and decreases with increasing doses. Currently, predicting clearance of methotrexate is difficult and exceedingly high serum levels of methotrexate can still occur when all precautions are taken.


In adults, oral absorption of methotrexate appears to be dose dependent. Peak serum levels are reached within one to two hours. At doses of 30 mg/sq m or less, methotrexate is generally well absorbed with a mean bioavailability of about 60%. The absorption of doses greater than 80 mg/sq m is significantly less, possibly due to a saturation effect.

Physicians Desk Reference. 58th ed. Thomson PDR. Montvale, NJ 2004., p. 806


After intravenous administration, the initial volume of distribution is approximately 0.18 L/kg (18% of body weight) and steady-state volume of distribution is approximately 0.4 to 0.8 L/kg (40% to 80% of body weight).

Physicians Desk Reference. 58th ed. Thomson PDR. Montvale, NJ 2004., p. 806


Protein binding: Moderate (approximately 50%), primarily to albumin.

Thomson.Micromedex. Drug Information for the Health Care Professional. 24th ed. Volume 1. Plus Updates. Content Reviewed by the United States Pharmacopeial Convention, Inc. Greenwood Village, CO. 2004., p. 1912


At serum methotrexate concentrations exceeding 0.1 umol/mL passive diffusion becomes a major means of intracellular transport of the drug. The drug is widely distributed into body tissues with highest concn in the kidneys, gallbladder, spleen, liver, and skin.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1113


For more Absorption, Distribution and Excretion (Complete) data for METHOTREXATE (10 total), please visit the HSDB record page.


5.6 Metabolism/Metabolites

Methotrexate is metabolized by folylpolyglutamate synthase to methotrexate polyglutamate in the liver as well as in tissues. Gamma-glutamyl hydrolase hydrolyzes the glutamyl chains of methotrexate polyglutamates converting them back to methotrexate. A small amount of methotrexate is also converted to 7-hydroxymethotrexate.


After absorption, methotrexate undergoes hepatic and intracellular metabolism to form methotrexate polyglutamate, metabolites which by hydrolysis may be converted back to methotrexate. Methotrexate polyglutamates inhibit dihydrofolate reductase and thymidylate synthetase. Small amounts of these polyglutamate metabolites may remain in tissues for extended periods; the retention and prolonged action of these active metabolites vary among different cells, tissues, and tumors. In addition, small amounts of methotrexate polyglutamate may be converted to 7-hydroxymethotrexate; accumulation of this metabolite may become substantial following administration of high doses of methotrexate, since the aqueous solubility of 7-hydroxymethotrexate is threefold to fivefold lower than that of the parent compound. Following oral administration of methotrexate, the drug also is partially metabolized by the intestinal flora.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1113


5.7 Biological Half-Life

The half life of low dose methotrexate is 3 to 10 hours in adults. The half life for high dose methotrexate is 8 to 15 hours. Pediatric patients taking methotrexate for acute lymphoblastic anemia experience a terminal half life of 0.7 to 5.8 hours. Pediatric patients taking methotrexate for juvenile idiopathic arthritis experience a half life of 0.9 to 2.3 hours.


Terminal: Low doses: 3 to 10 hours. High doses: 8 to 15 hours. Note: There is wide interindividual variation in clearance rates. Small amounts of methotrexate and its metabolites are protein-bound and may remain in tissues (kidneys, liver) for weeks to months; the presence of fluid loads, such as ascites or pleural effusion, and renal function impairment will also delay clearance.

Thomson.Micromedex. Drug Information for the Health Care Professional. 24th ed. Volume 1. Plus Updates. Content Reviewed by the United States Pharmacopeial Convention, Inc. Greenwood Village, CO. 2004., p. 1912


5.8 Mechanism of Action

Methotrexate enters tissues and is converted to a methotrexate polyglutamate by folylpolyglutamate. Methotrexate's mechanism of action is due to its inhibition of enzymes responsible for nucleotide synthesis including dihydrofolate reductase, thymidylate synthase, aminoimidazole caboxamide ribonucleotide transformylase (AICART), and amido phosphoribosyltransferase. Inhibtion of nucleotide synthesis prevents cell division. In rheumatoid arthritis, methotrexate polyglutamates inhibit AICART more than methotrexate. This inhibition leads to accumulation of AICART ribonucleotide, which inhibits adenosine deaminase, leading to an accumulation of adenosine triphosphate and adenosine in the extracellular space, stimulating adenosine receptors, leading to anti-inflammatory action.


Methotrexate and its polyglutanate metabolites reversibly inhibits dihydrofolate reductase, the enzyme that reduces folic acid to tetrahydrofolic acid. Inhibition of tetrahydrofolate formation limits the availability of one-carbon fragments necessary for synthesis of purines and the conversion of deoxyuridylate to thymidylate in the synthesis of DNA and cell reproduction. The affinity of dihydrofolate reductase for methotrexate is far greater than its affinity for folic acid or dihydrofolic acid. and, therefore, even very large doses of folic acid given simultaneously will not reverse the effects of methotrexate. Leucovorin calcium, a derivative of tetrahydrofolic acid, may block the effects of methotrexate if given shortly after the antineoplastic agent. Results of one study indicate that methotrexate also causes an increase in intracellular deoxyadenosine triphosphate, which is thought to inhibit ribonucleotide reduction, and polynucleotide ligase, an enzyme concerned in DNA synthesis and repair. Tissues with high rates of cellular proliferation such as neoplasms, psoriatic epidermis, bone marrow, the lining of the GI tract, hair matrix, and fetal cells are most sensitive to the effects of methotrexate.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1113


Methotrexate ... has immunosuppressive activity, in part possibly as a result of inhibition of lymphocyte multiplication. The mechanism(s) of action in the management of rheumatoid arthritis of the drug is not known, although suggested mechanisms have included immunosuppressive and/or antiinflammatory effects.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 1113