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2D Structure
Also known as: 738-70-5, Proloprim, Trimpex, Trimetoprim, Bactramin, Monotrim
Molecular Formula
C14H18N4O3
Molecular Weight
290.32  g/mol
InChI Key
IEDVJHCEMCRBQM-UHFFFAOYSA-N
FDA UNII
AN164J8Y0X

A pyrimidine inhibitor of dihydrofolate reductase, it is an antibacterial related to PYRIMETHAMINE. It is potentiated by SULFONAMIDES and the TRIMETHOPRIM, SULFAMETHOXAZOLE DRUG COMBINATION is the form most often used. It is sometimes used alone as an antimalarial. TRIMETHOPRIM RESISTANCE has been reported.
Trimethoprim is a Dihydrofolate Reductase Inhibitor Antibacterial. The mechanism of action of trimethoprim is as a Dihydrofolate Reductase Inhibitor, and Cytochrome P450 2C8 Inhibitor, and Organic Cation Transporter 2 Inhibitor.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidine-2,4-diamine
2.1.2 InChI
InChI=1S/C14H18N4O3/c1-19-10-5-8(6-11(20-2)12(10)21-3)4-9-7-17-14(16)18-13(9)15/h5-7H,4H2,1-3H3,(H4,15,16,17,18)
2.1.3 InChI Key
IEDVJHCEMCRBQM-UHFFFAOYSA-N
2.1.4 Canonical SMILES
COC1=CC(=CC(=C1OC)OC)CC2=CN=C(N=C2N)N
2.2 Other Identifiers
2.2.1 UNII
AN164J8Y0X
2.3 Synonyms
2.3.1 MeSH Synonyms

1. Proloprim

2. Trimpex

2.3.2 Depositor-Supplied Synonyms

1. 738-70-5

2. Proloprim

3. Trimpex

4. Trimetoprim

5. Bactramin

6. Monotrim

7. Monotrimin

8. Trimopan

9. Wellcoprim

10. 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine

11. Monoprim

12. Syraprim

13. Trimanyl

14. Triprim

15. Uretrim

16. 5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4-diamine

17. Trimethoprimum

18. Trimethoprime

19. 5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidine-2,4-diamine

20. Nsc-106568

21. Nih 204

22. Primsol

23. Component Of Bactrim

24. Bw 56-72

25. 2,4-pyrimidinediamine, 5-[(3,4,5-trimethoxyphenyl)methyl]-

26. Infectotrimet

27. Polytrim

28. Tcmdc-125538

29. 5-(3,4,5-trimethoxybenzyl)-2,4-pyrimidinediamine

30. Trimethoprim-d9

31. 5-[(3,4,5-trimethoxyphenyl)methyl]-2,4-pyrimidinediamine

32. Nsc 106568

33. 5-(3,4,5-trimethoxybenzyl)-2,4-diaminopyrimidine

34. Bw-56-72

35. Chebi:45924

36. Chembl22

37. Trimpex (tn)

38. 2,4-pyrimidinediamine, 5-((3,4,5-trimethoxyphenyl)methyl)-

39. Abaprim

40. Mfcd00036761

41. Apo-sulfatrim

42. Bw 5672

43. Pyrimidine, 2,4-diamino-5-(3,4,5-trimethoxybenzyl)-

44. Mls000079023

45. An164j8y0x

46. Briscotrim

47. Novotrimel

48. Streptoplus

49. Sulfoxaprim

50. Trimethioprim

51. Urobactrim

52. Wellcoprin

53. Anitrim

54. Antrima

55. Antrimox

56. Bacidal

57. Bacticel

58. Bactoprim

59. Bencole

60. Bethaprim

61. Biosulten

62. Chemotrin

63. Colizole

64. Conprim

65. Cotrimel

66. Duocide

67. Esbesul

68. Espectrin

69. Euctrim

70. Exbesul

71. Fermagex

72. Fortrim

73. Ikaprim

74. Kombinax

75. Lagatrim

76. Lastrim

77. Metoprim

78. Pancidim

79. Protrin

80. Resprim

81. Salvatrim

82. Setprin

83. Sinotrim

84. Sugaprim

85. Sulfamar

86. Sulthrim

87. Sultrex

88. Trimexol

89. Trimezol

90. Trimono

91. Trisulcom

92. Trisulfam

93. Trisural

94. Utetrin

95. Velaten

96. Xeroprim

97. Zamboprim

98. 2,4-pyrimidinediamine, 5-((3,4,5-trimethoxyphenyl)-methyl)-

99. Bacdan

100. Bacide

101. Deprim

102. Omstat

103. Purbal

104. Roubac

105. Roubal

106. Stopan

107. Toprim

108. Trisul

109. Bacin

110. Bacta

111. Futin

112. Nih-204

113. Trimpex 200

114. Co-trimoxizole

115. Lagatrim Forte

116. Septrin Forte

117. Alcorim-f

118. Colizole Ds

119. Septrin S

120. Septrin Ds

121. Smz-tmp

122. Nsc106568

123. Trimez-ifsa

124. U-prin

125. Component Of Septra

126. Ncgc00016055-05

127. Trimethopriom

128. 5-((3,4,5-trimethoxyphenyl)methyl)-2,4-pyrimidinediamine

129. Bactifor

130. Cas-738-70-5

131. Dosulfin

132. Instalac

133. Smr000035999

134. Trimetoprim [dcit]

135. Trimogal

136. Lescot

137. Tiempe

138. Trimetoprim [polish]

139. Resprim Forte

140. Trimethoprim 100 Microg/ml In Acetonitrile

141. Uro-d S

142. Dsstox_cid_3712

143. Tmp Smx

144. Dsstox_rid_77158

145. Dsstox_gsid_23712

146. 5-(3,4,5-trimethoxy-benzyl)-pyrimidine-2,4-diamine

147. Trimethoprime [inn-french]

148. Trimethoprimum [inn-latin]

149. Trimetoprima [inn-spanish]

150. 2,4-diamino-5-(3',4',5'-trimethoxybenzyl)pyrimidine

151. Bacterial [antibiotic]

152. Nih 204 (van)

153. Trimethoprim D3 (4-methoxy D3)

154. Proloprim (tn)

155. Wr 5949

156. Ccris 2410

157. Hsdb 6781

158. Sr-01000075652

159. Einecs 212-006-2

160. 5-(3, 4, 5-trimethoxybenzyl)-2, 4-pyrimidinediamine

161. Brn 0625127

162. Unii-an164j8y0x

163. Trimethoprim (jan/usp/inn)

164. 5-{[3,4,5-tris(methyloxy)phenyl]methyl}pyrimidine-2,4-diamine

165. Ai3-52594

166. Trimethoprim D3 (4-methoxy D3) 100 Microg/ml In Acetonitrile

167. B-lock

168. Kuc103659n

169. Trimethoprim,(s)

170. Prestwick_485

171. Ksc-4-158

172. Trimethoprim (tmp)

173. Bactrim (salt/mix)

174. Azt + Tmp/smx (mixture) Combination

175. Spectrum_000167

176. Tocris-0650

177. Trimethoprim [usan:usp:inn:ban:jan]

178. 2w9h

179. 3fl9

180. 3n0h

181. 3s3v

182. 4km2

183. Opera_id_1760

184. Prestwick0_000208

185. Prestwick1_000208

186. Prestwick2_000208

187. Prestwick3_000208

188. Spectrum2_000937

189. Spectrum3_000643

190. Spectrum4_000372

191. Spectrum5_001559

192. Lopac-t-7883

193. Trimethoprim [mi]

194. Trimethoprim [inn]

195. Trimethoprim [jan]

196. Epitope Id:119684

197. Upcmld-dp132

198. T 7883

199. Trimethoprim [hsdb]

200. Trimethoprim [usan]

201. Trimethoprim [vandf]

202. Lopac0_001271

203. Oprea1_495058

204. Schembl24506

205. Bspbio_000195

206. Bspbio_002245

207. Kbiogr_000863

208. Kbioss_000647

209. Trimethoprim [mart.]

210. 5-25-13-00429 (beilstein Handbook Reference)

211. Mls001201740

212. Mls002303068

213. Mls002548881

214. Bidd:gt0190

215. Divk1c_000589

216. Spectrum1500595

217. Trimethoprim [usp-rs]

218. Trimethoprim [who-dd]

219. Spbio_000874

220. Spbio_002116

221. Bpbio1_000215

222. Dtxsid3023712

223. Upcmld-dp132:001

224. Bdbm18069

225. Gtpl10931

226. Hms501n11

227. Kbio1_000589

228. Kbio2_000647

229. Kbio2_003215

230. Kbio2_005783

231. Kbio3_001465

232. Trimethoprim [green Book]

233. Trimethoprim, >=98% (hplc)

234. Ninds_000589

235. 2,4,5-trimethoxybenzyl)pyrimidine

236. Hms1568j17

237. Hms1921i03

238. Hms2090d14

239. Hms2092a10

240. Hms2095j17

241. Hms2230l06

242. Hms3259i11

243. Hms3263p04

244. Hms3371o18

245. Hms3652e03

246. Hms3712j17

247. Pharmakon1600-01500595

248. Trimethoprim [ep Impurity]

249. Trimethoprim [orange Book]

250. Trimethoprim For System Suitability

251. Trimethoprim [ep Monograph]

252. 2,4,5-trimethoxyphenzyl)pyrimidine

253. Albb-028968

254. Bcp12148

255. Cotrim Component Trimethoprim

256. Hy-b0510

257. Septra Component Trimethoprim

258. Zinc6627681

259. Co-trimoxazole Component Trimethoprim

260. Tox21_110291

261. Tox21_200157

262. Tox21_501271

263. Trimethoprim [usp Monograph]

264. Bactrim Component Trimethoprim

265. Bbl005584

266. Ccg-40335

267. Nsc752719

268. Nsc757370

269. S3129

270. Stk177322

271. Stl455117

272. Uroplus Component Trimethoprim

273. Trimethoprimum [who-ip Latin]

274. Akos001650069

275. Sulfatrim Component Trimethoprim

276. Sulmeprim Component Trimethoprim

277. Tox21_110291_1

278. Ac-8427

279. Bw-5672

280. Db00440

281. Ks-1145

282. Lp01271

283. Nc00483

284. Nsc-752719

285. Nsc-757370

286. Sdccgsbi-0051237.p004

287. Trimethoprim Component Of Cotrim

288. Trimethoprim Component Of Septra

289. Bactrim Ds Component Trimethoprim

290. Idi1_000589

291. Smp2_000262

292. Trimethoprim 100 Microg/ml In Methanol

293. Trimethoprim Component Of Bactrim

294. Trimethoprim Component Of Uroplus

295. Ncgc00016055-01

296. Ncgc00016055-02

297. Ncgc00016055-03

298. Ncgc00016055-04

299. Ncgc00016055-06

300. Ncgc00016055-07

301. Ncgc00016055-08

302. Ncgc00016055-09

303. Ncgc00016055-10

304. Ncgc00016055-11

305. Ncgc00016055-12

306. Ncgc00016055-13

307. Ncgc00016055-14

308. Ncgc00016055-16

309. Ncgc00016055-17

310. Ncgc00016055-27

311. Ncgc00024707-01

312. Ncgc00024707-03

313. Ncgc00024707-04

314. Ncgc00024707-05

315. Ncgc00024707-06

316. Ncgc00024707-07

317. Ncgc00024707-08

318. Ncgc00257711-01

319. Ncgc00261956-01

320. Cotrim D.s. Component Trimethoprim

321. Sy031734

322. Trimethoprim Component Of Sulfatrim

323. Trimethoprim Component Of Sulmeprim

324. Trimethoprim/sulfamethoxazole (commercial)

325. Sbi-0051237.p003

326. Db-055812

327. Sulfamethoprim Component Trimethoprim

328. Trimethoprim Component Of Bactrim Ds

329. 2, 5-[(3,4,5-trimethoxyphenyl)methyl]-

330. Ab00052118

331. Bb 0258034

332. Eu-0101271

333. Ft-0601630

334. Ft-0675578

335. Ft-0675579

336. Ft-0675580

337. Sw196690-3

338. T2286

339. Trimethoprim 1000 Microg/ml In Acetonitrile

340. Trimethoprim Component Of Cotrim D.s.

341. Bactrim Pediatric Component Trimethoprim

342. C01965

343. D00145

344. Trimethoprim Component Of Sulfamethoprim

345. Trimethoprim, Crystallized, >=99.0% (hplc)

346. Wln: T6n Cnj Bz Dz E1r Co1 Do1 Eo1

347. 5-(3,5-trimethoxybenzyl)-2,4-diaminopyrimidine

348. Ab00052118-30

349. Ab00052118-32

350. Ab00052118_33

351. Ab00052118_34

352. Trimethoprim, Vetranal(tm), Analytical Standard

353. 738t705

354. Formulated Trimethoprim (nsc 106568) In Ethanol

355. Q422665

356. Trimethoprim Component Of Bactrim Pediatric

357. 2,4-diamino-5-(3,4,5-trimethoxybenzyl) Pyrimidine

358. 2,4-diamino-5-(3,4,5-trimethoxybenzyl)-pyrimidine

359. Pyrimidine,4-diamino-5-(3,4,5-trimethoxybenzyl)-

360. Sr-01000075652-1

361. Sr-01000075652-3

362. Sr-01000075652-6

363. W-104441

364. 5-(3,4,5-trimethoxybenzyl)-2,4-pyrimidinediamine #

365. Brd-k07208025-001-06-5

366. Sr-01000075652-10

367. 2-amino-5-(3,4,5-trimethoxybenzyl)-4-pyrimidinylamine

368. F0914-5266

369. Trimethoprim, Certified Reference Material, Tracecert(r)

370. Z1522566629

371. 5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4(1h,3h)-diimine

372. Trimethoprim, British Pharmacopoeia (bp) Reference Standard

373. Trimethoprim, European Pharmacopoeia (ep) Reference Standard

374. Trimethoprim, United States Pharmacopeia (usp) Reference Standard

375. Trimethoprim For System Suitability, European Pharmacopoeia (ep) Reference Standard

376. Trimethoprim, Pharmaceutical Secondary Standard; Certified Reference Material

2.4 Create Date
2005-03-25
3 Chemical and Physical Properties
Molecular Weight 290.32 g/mol
Molecular Formula C14H18N4O3
XLogP30.9
Hydrogen Bond Donor Count2
Hydrogen Bond Acceptor Count7
Rotatable Bond Count5
Exact Mass290.13789045 g/mol
Monoisotopic Mass290.13789045 g/mol
Topological Polar Surface Area106 Ų
Heavy Atom Count21
Formal Charge0
Complexity307
Isotope Atom Count0
Defined Atom Stereocenter Count0
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 6  
Drug NamePolytrim
PubMed HealthTrimethoprim (By mouth)
Drug ClassesAntibiotic, Antiseptic
Active Ingredienttrimethoprim sulfate; Polymyxin b sulfate
Dosage FormSolution/drops
RouteOphthalmic
Strength10,000 units/ml; eq 1mg base/ml
Market StatusPrescription
CompanyAllergan

2 of 6  
Drug NamePrimsol
PubMed HealthTrimethoprim (By mouth)
Drug ClassesAntibiotic, Antiseptic
Active IngredientTrimethoprim hydrochloride
Dosage FormSolution
RouteOral
Strengtheq 50mg base/5ml
Market StatusPrescription
CompanyFsc

3 of 6  
Drug NameTrimethoprim
Drug LabelTrimethoprim is a synthetic antibacterial available as 100 mg tablets for oral administration.Trimethoprim is 2,4-Diamino-5-(3,4,5-trimethoxybenzyl) pyrimidine. It is a white to cream colored, odorless, bitter compound. The structural formula is repr...
Active IngredientTrimethoprim
Dosage FormTablet
RouteOral
Strength100mg
Market StatusPrescription
CompanyTeva; Novel Labs; Watson Labs

4 of 6  
Drug NamePolytrim
PubMed HealthTrimethoprim (By mouth)
Drug ClassesAntibiotic, Antiseptic
Active Ingredienttrimethoprim sulfate; Polymyxin b sulfate
Dosage FormSolution/drops
RouteOphthalmic
Strength10,000 units/ml; eq 1mg base/ml
Market StatusPrescription
CompanyAllergan

5 of 6  
Drug NamePrimsol
PubMed HealthTrimethoprim (By mouth)
Drug ClassesAntibiotic, Antiseptic
Active IngredientTrimethoprim hydrochloride
Dosage FormSolution
RouteOral
Strengtheq 50mg base/5ml
Market StatusPrescription
CompanyFsc

6 of 6  
Drug NameTrimethoprim
Drug LabelTrimethoprim is a synthetic antibacterial available as 100 mg tablets for oral administration.Trimethoprim is 2,4-Diamino-5-(3,4,5-trimethoxybenzyl) pyrimidine. It is a white to cream colored, odorless, bitter compound. The structural formula is repr...
Active IngredientTrimethoprim
Dosage FormTablet
RouteOral
Strength100mg
Market StatusPrescription
CompanyTeva; Novel Labs; Watson Labs

4.2 Therapeutic Uses

Anti-Infective Agents, Urinary; Antimalarials; Antimetabolites; Folic Acid Antagonists

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


Trimethoprim given alone has also been effective for urinary tract infections, but the development of resistant organisms limits the usefulness of this treatment.

Gilman, A.G., T.W. Rall, A.S. Nies and P. Taylor (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 8th ed. New York, NY. Pergamon Press, 1990., p. 1056


Trimethoprim is indicated in the treatment of initial, uncomplicated urinary tract infections caused by susceptible strains of Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter species, & coagulase-negative Staphylococcus species, including Staphylococcus saprophyticus. /Included in US product labeling/

MICROMEDEX Thomson Health Care. USPDI - Drug Information for the Health Care Professional. 22nd ed. Volume 1. MICROMEDEX Thomson Health Care, Greenwood Village, CO. 2002. Content Reviewed and Approved by the U.S. Pharmacopeial Convention, Inc., p. 2848


trimethoprim is used in the prophylaxis of bacterial urinary tract infections. /NOT included in US product labeling/

MICROMEDEX Thomson Health Care. USPDI - Drug Information for the Health Care Professional. 22nd ed. Volume 1. MICROMEDEX Thomson Health Care, Greenwood Village, CO. 2002. Content Reviewed and Approved by the U.S. Pharmacopeial Convention, Inc., p. 2848


For more Therapeutic Uses (Complete) data for TRIMETHOPRIM (8 total), please visit the HSDB record page.


4.3 Drug Warning

Because trimethoprim may interfere with folic acid metabolism, the drug should be used with caution in nursing women.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 842


Adverse GI reactions occur in approximately 6% of patients receiving trimethoprim and may include epigastric discomfort, nausea, vomiting, glossitis, and abnormal taste sensation. Elevations in serum aminotransferase (transaminase) and bilirubin concentrations have been reported in patients receiving the drug, but the clinical importance of these findings is not known. Cholestatic jaundice has been reported rarely.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 842


The most frequent adverse effects of trimethoprim are rash and pruritus. Mild to moderate rashes appearing 7-14 days after initiation of trimethoprim therapy reportedly occur in 2.9-6.7% of patients receiving 200 mg of the drug daily. Rashes are generally maculopapular, morbilliform, and pruritic. Rashes have been reported to occur in up to 24% of patients receiving 400 mg or more trimethoprim for 14 days. Photosensitivity (e.g., erythematous phototoxic eruptions with subsequent hyperpigmentation of sun-exposed skin) also has occurred. Exfoliative dermatitis, toxic epidermal necrolysis (Lyell's syndrome), erythema multiforme, and Stevens-Johnson syndrome have been reported rarely in patients receiving the drug. Anaphylaxis also has occurred rarely.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 842


Safety and efficacy of trimethoprim in infants younger than 2 months of age and efficacy of the drug when used as single agent in children younger than 12 years of age have not been established. Trimethoprim should be used with caution in children who have the fragile X chromosome associated with mental retardation, because folate depletion may worsen the psychomotor regression associated with the disorder.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 842


For more Drug Warnings (Complete) data for TRIMETHOPRIM (28 total), please visit the HSDB record page.


4.4 Drug Indication

As a monotherapy, trimethoprim is indicated for the treatment of acute episodes of uncomplicated urinary tract infections caused by susceptible bacteria, including _E. coli._, _K. pneumoniae_, _Enterobacter spp._, _P. mirabilis_, and coagulase-negative _Staphylococcus_ species. In various formulations in combination with [sulfamethoxazole], trimethoprim is indicated for the following infections caused by bacteria with documented susceptibility: urinary tract infections, acute otitis media in pediatric patients (when clinically indicated), acute exacerbations of chronic bronchitis in adults, enteritis caused by susceptible _Shigella_, prophylaxis and treatment of _Pneumocystis jiroveci_ pneumonia, and travelers' diarrhea caused by enterotoxigenic _E. coli_. Trimethoprim is available as an ophthalmic solution in combination with [polymyxin B] for the treatment of acute bacterial conjunctivitis, blepharitis, and blepharoconjunctivitis caused by susceptible bacteria.


FDA Label


5 Pharmacology and Biochemistry
5.1 Pharmacology

Trimethoprim exerts its antimicrobial effects by inhibiting an essential step in the synthesis of bacterial nucleic acids and proteins. It has shown activity against several species of gram-negative bacteria, as well as coagulase-negative _Staphylococcus_ species. Resistance to trimethoprim may arise via a variety of mechanisms, including alterations to the bacterial cell wall, overproduction of dihydrofolate reductase, or production of resistant dihydrofolate reductase. Rarely, trimethoprim can precipitate the development of blood disorders (e.g. thrombocytopenia, leukopenia, etc.) which may be preceded by symptoms such as sore throat, fever, pallor, and or purpura - patients should be monitored closely for the development of these symptoms throught the course of therapy. As antimicrobial susceptibility patterns are geographically distinct, local antibiograms should be consulted to ensure adequate coverage of relevant pathogens prior to use.


5.2 MeSH Pharmacological Classification

Cytochrome P-450 CYP2C8 Inhibitors

Drugs and compounds which inhibit or antagonize the biosynthesis or actions of CYTOCHROME P-450 CYP2C8. (See all compounds classified as Cytochrome P-450 CYP2C8 Inhibitors.)


Anti-Infective Agents, Urinary

Substances capable of killing agents causing urinary tract infections or of preventing them from spreading. (See all compounds classified as Anti-Infective Agents, Urinary.)


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.)


Antimalarials

Agents used in the treatment of malaria. They are usually classified on the basis of their action against plasmodia at different stages in their life cycle in the human. (From AMA, Drug Evaluations Annual, 1992, p1585) (See all compounds classified as Antimalarials.)


Anti-Dyskinesia Agents

Drugs used in the treatment of movement disorders. Most of these act centrally on dopaminergic or cholinergic systems. Among the most important clinically are those used for the treatment of Parkinson disease (ANTIPARKINSON AGENTS) and those for the tardive dyskinesias. (See all compounds classified as Anti-Dyskinesia Agents.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
TRIMETHOPRIM
5.3.2 FDA UNII
AN164J8Y0X
5.3.3 Pharmacological Classes
Dihydrofolate Reductase Inhibitor Antibacterial [EPC]; Dihydrofolate Reductase Inhibitors [MoA]; Organic Cation Transporter 2 Inhibitors [MoA]; Cytochrome P450 2C8 Inhibitors [MoA]
5.4 ATC Code

J01EE01

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


J - Antiinfectives for systemic use

J01 - Antibacterials for systemic use

J01E - Sulfonamides and trimethoprim

J01EA - Trimethoprim and derivatives

J01EA01 - Trimethoprim


5.5 Absorption, Distribution and Excretion

Absorption

Steady-state concentrations are achieved after approximately 3 days of repeat administration. Average peak serum concentrations of approximately 1 g/mL (Cmax) are achieved within 1 to 4 hours (Tmax) following the administration of a single 100mg dose. Trimethoprim appears to follow first-order pharmacokinetics, as a single 200mg dose results in serum concentrations approximately double that of a 100mg dose. The steady-state AUC of orally administered trimethoprim is approximately 30 mg/Lh.


Route of Elimination

Approximately 10-20% of an ingested trimethoprim dose is metabolized, primarily in the liver, while a large portion of the remainder is excreted unchanged in the urine. Following oral administration, 50% to 60% of trimethoprim is excreted in the urine within 24 hours, approximately 80% of which is unchanged parent drug.


Volume of Distribution

Trimethoprim is extensively distributed into various tissues following oral administration. It distributes well into sputum, middle ear fluid, and bronchial secretions. Trimethoprim distributes efficiently into vaginal fluids, with observed concentrations approximately 1.6-fold higher than those seen in the serum. It may pass the placental barrier and into breast milk. Trimethoprim is also sufficiently excreted in the feces to markedly reduce and/or eliminate trimethoprim-susceptible fecal flora.


Clearance

Following oral administration, the renal clearance of trimethoprim has been variably reported between 51.7 - 91.3 mL/min.


Trimethoprim is widely distributed into body tissues & fluids including the aqueous humor, middle ear fluid, saliva, lung tissue, sputum, seminal fluid, prostatic tissue & fluid, vaginal secretions, bile, bone, & /cerebrospinal fluid/. The apparent volume of distribution of trimethoprim in adults with normal renal function ranges from 100-120 l. ... Trimethoprim is 42-46% bound to plasma proteins. Trimethoprim readily crosses the placenta, & amniotic fluid concns are reported to be 80% of concurrent maternal serum concns.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 843


Only small amounts of trimethoprim are excreted in feces via biliary elimination. Trimethoprim may be moderately removed by hemodialysis.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 844


Trimethoprim is readily & almost completely absorbed from the GI tract. Peak serum concns of approx 1, 1.6, & 2 ug/ml are reached in 1-4 hr after single 100-, 160-, & 200 mg oral doses of trimethoprim. Following multiple-dose oral admin, steady-state peak serum concns of trimethoprim usually are 50% greater than those obtained after single-dose admin of the drug. Steady-state serum concns range from 1.2-3.2 ug/ml following oral admin of 160 mg of trimethoprim every 12 hr in adults with renal function.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 843


Rapidly and widely distributed to various tissues and fluids, including kidneys, liver, spleen, bronchial secretions, saliva, and seminal fluid. Trimethoprim has also been demonstrated in bile; aqueous humor; bone marrow and spongy, but not compact, bone.

MICROMEDEX Thomson Health Care. USPDI - Drug Information for the Health Care Professional. 22nd ed. Volume 1. MICROMEDEX Thomson Health Care, Greenwood Village, CO. 2002. Content Reviewed and Approved by the U.S. Pharmacopeial Convention, Inc., p. 2849


For more Absorption, Distribution and Excretion (Complete) data for TRIMETHOPRIM (12 total), please visit the HSDB record page.


5.6 Metabolism/Metabolites

Trimethoprim undergoes oxidative metabolism to a number of metabolites, the most abundant of which are the demethylated 3'- and 4'- metabolites, accounting for approximately 65% and 25% of the total metabolite formation, respectively. Minor products include N-oxide metabolites (<5%) and benzylic metabolites in even smaller quantities. The parent drug is considered to be the therapeutically active form. The majority of trimethoprim biotransformation appears to involve CYP2C9 and CYP3A4 enzymes, with CYP1A2 contributing to a lesser extent.


Trimethoprim is metabolized in the liver to oxide and hydroxylated metabolites ... .

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 844


The pharmacokinetics were studied of sulfadimethoxine (SDM) or sulfamethoxazole (SMX) in combination with trimethoprim (TMP) administered as a single oral dose (25 mg + 5 mg/kg bw) to 2 groups of 6 healthy pigs. The elimination half-lives of SMX & TMP were quite similar (2-3 hr); SDM had a relatively long half-life of 13 hr. Both sulfonamides (S) were exclusively metabolized to N4-acetyl derivatives but to different extents. The main metabolic pathway for TMP was O-demethylation & subsequent conjugation. In addition, the plasma concns of these drugs & their main metabolites after medication with different in-feed concns were determined. The drug (S:TMP) concns in the feed were 250:50, 500:100, & 1000:200 mg/kg. Steady-state concns were achieved within 48 hr of feed medication, twice daily (SDM+TMP) or 3 times/day (SMX+TMP). Protein binding of SDM & its metabolite was high (>93%), whereas SMX, TMP & their metabolites showed moderate binding (48-75%). Feed medication with 500 ppm sulfonamide combined with 100 ppm TMP provided minimum steady-state plasma concns (C(ss,min)) higher than the concn required for inhibition of the growth of 90% of Actinobacillus pleuropneumoniae strains (n=20).

Mengelers MF, et al; Vet Res Commun 25 (6): 461-481. 2001.


5.7 Biological Half-Life

Trimethoprim half-life ranges from 8-10 hours, but may be prolonged in patients with renal dysfunction.


Trimethoprim has a serum half-life of approx 8-11 hr in adults with normal renal function. In adults with creatinine clearances of 10-30 or 0-10 ml/min, serum half-life of the drug may incr to 15 hr or >26 hr, respectively. Trimethoprim serum half-lives of about 7.7 & 5.5 hr have been reported in children <1 yr of age & between 1 & 10 yr of age, respectively.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2002. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2002 (Plus Supplements)., p. 843


5.8 Mechanism of Action

Trimethoprim is a reversible inhibitor of dihydrofolate reductase, one of the principal enzymes catalyzing the formation of tetrahydrofolic acid (THF) from dihydrofolic acid (DHF). Tetrahydrofolic acid is necessary for the biosynthesis of bacterial nucleic acids and proteins and ultimately for continued bacterial survival - inhibiting its synthesis, then, results in bactericidal activity. Trimethoprim binds with a much stronger affinity to bacterial dihydrofolate reductase as compared to its mammalian counterpart, allowing trimethoprim to selectively interfere with bacterial biosynthetic processes. Trimethoprim is often given in combination with sulfamethoxazole, which inhibits the preceding step in bacterial protein synthesis - given together, sulfamethoxazole and trimethoprim inhibit two consecutive steps in the biosynthesis of bacterial nucleic acids and proteins. As a monotherapy trimethoprim is considered bacteriostatic, but in combination with sulfamethoxazole is thought to exert bactericidal activity.


Trimethoprim is a bacteriostatic lipophilic weak base structurally related to pyrimethamine. It binds to and reversibly inhibits the bacterial enzyme dihydrofolate reductase, selectively blocking conversion of dihydrofolic acid to its functional form, tetrahydrofolic acid. This depletes folate, an essential cofactor in the biosynthesis of nucleic acids, resulting in interference with bacterial nucleic acid and protein production. Bacterial dihydrofolate reductase is approximately 50,000 to 60,000 times more tightly bound by trimethoprim than is the corresponding mammalian enzyme.

US Pharmacopeial Convention; US Pharmacopeia Dispensing Information (USP DI); Drug Information for the Health Care Professional 12th ed, V.IB p.2531 (1992)


To determine the incidence & severity of hyperkalemia during trimethoprim therapy, 30 consecutive patients with acquired immunodeficiency syndrome receiving high-dose (20 mg/kg/day) trimethoprim were studied; in addition, the mechanism of trimethoprim-induced hyperkalemia was investigated in rats. Trimethoprim increased serum potassium concn by 0.6 mmol/l despite normal adrenocortical function & glomerular filtration rate. Serum potassium levels >5 mmol/l were observed during trimethoprim treatment in 15 of 30 patients. In rats, iv trimethoprim inhibited renal potassium excretion by 40% & increased sodium excretion by 46%. It was concluded that trimethoprim blocks apical membrane sodium channels in the mammalian distal nephron. As a consequence, the transepithelial voltage is reduced & potassium secretion is inhibited. Decreased renal potassium excretion secondary to these direct effects on kidney tubules leads to hyperkalemia in a substantial number of patients being treated with trimethoprim-containing drugs.

PMID:8328738 Velazquez H, et al; Ann. Intern. Med. 119 (Aug 15): 296-301 (1993)