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2D Structure
Also known as: 58-08-2, Guaranine, 1,3,7-trimethylxanthine, Methyltheobromine, Theine, Thein
Molecular Formula
C8H10N4O2
Molecular Weight
194.19  g/mol
InChI Key
RYYVLZVUVIJVGH-UHFFFAOYSA-N
FDA UNII
3G6A5W338E

A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.
Caffeine is a Central Nervous System Stimulant and Methylxanthine. The physiologic effect of caffeine is by means of Central Nervous System Stimulation.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
1,3,7-trimethylpurine-2,6-dione
2.1.2 InChI
InChI=1S/C8H10N4O2/c1-10-4-9-6-5(10)7(13)12(3)8(14)11(6)2/h4H,1-3H3
2.1.3 InChI Key
RYYVLZVUVIJVGH-UHFFFAOYSA-N
2.1.4 Canonical SMILES
CN1C=NC2=C1C(=O)N(C(=O)N2C)C
2.2 Other Identifiers
2.2.1 UNII
3G6A5W338E
2.3 Synonyms
2.3.1 MeSH Synonyms

1. 1,3,7-trimethylxanthine

2. Caffedrine

3. Coffeinum N

4. Coffeinum Purrum

5. Dexitac

6. Durvitan

7. No Doz

8. Percoffedrinol N

9. Percutafine

10. Quick Pep

11. Quick-pep

12. Quickpep

13. Vivarin

2.3.2 Depositor-Supplied Synonyms

1. 58-08-2

2. Guaranine

3. 1,3,7-trimethylxanthine

4. Methyltheobromine

5. Theine

6. Thein

7. Cafeina

8. Koffein

9. Mateina

10. Alert-pep

11. Caffein

12. Cafipel

13. Coffeine

14. Refresh'n

15. Caffedrine

16. Vivarin

17. Anhydrous Caffeine

18. Stim

19. Cafamil

20. Cafecon

21. Caffine

22. Dexitac

23. Nodaca

24. No-doz

25. Eldiatric C

26. 7-methyltheophylline

27. Durvitan

28. Hycomine

29. Organex

30. Nix Nap

31. Methyltheobromide

32. Coffeinum

33. Coffein

34. Phensal

35. 1,3,7-trimethylpurine-2,6-dione

36. 3,7-dihydro-1,3,7-trimethyl-1h-purine-2,6-dione

37. Caffeine, Synthetic

38. Quick-pep

39. Synalgos

40. Tirend

41. 1,3,7-trimethyl-2,6-dioxopurine

42. Theophylline, 7-methyl

43. Dhcplus

44. Tri-aqua

45. 1h-purine-2,6-dione, 3,7-dihydro-1,3,7-trimethyl-

46. Kofein

47. Miudol

48. Caffeine, Anhydrous

49. Theobromine, 1-methyl-

50. Propoxyphene Compound 65

51. 1,3,7-trimethyl-3,7-dihydro-1h-purine-2,6-dione

52. Kofein [czech]

53. Coffein [german]

54. Koffein [german]

55. 1-methyltheobromine

56. Caffeine (natural)

57. Xanthine, 1,3,7-trimethyl

58. Caffeina [italian]

59. Theophylline Me

60. Methylxanthine Theophylline

61. Theobromine Me

62. Nci-c02733

63. Sk-65 Compound

64. Anacin

65. Anacin Maximum Strength

66. Caffeine Anhydrous

67. Fema No. 2224

68. P-a-c Analgesic Tablets

69. C8h10n4o2

70. Hsdb 36

71. Caffeinum

72. Brn 0017705

73. 1,3,7-trimethyl-2,3,6,7-tetrahydro-1h-purine-2,6-dione

74. Nsc 5036

75. A.s.a. And Codeine Compound

76. 1,3,7-trimethyl-1h-purine-2,6(3h,7h)-dione

77. Ai3-20154

78. Nsc-5036

79. Chembl113

80. Caffeine Melting Point Standard

81. Cff

82. Chebi:27732

83. 3g6a5w338e

84. Mfcd00005758

85. Caffenium

86. Sk 65 Compound

87. Caffeina

88. Dsstox_cid_232

89. Caffeine [ban:jan]

90. Caffeine-d3

91. Dsstox_rid_75448

92. Dsstox_gsid_20232

93. Cafeine

94. Teina

95. Cas-58-08-2

96. Caffeine (usp)

97. Smr000326667

98. Ccris 1314

99. Sr-01000075187

100. Anhydrous Caffeine (tn)

101. Einecs 200-362-1

102. Monomethyl Derivative Of Theophylline

103. Caffeine [usp:ban:jan]

104. Anhydrous Caffeine (jp15)

105. Unii-3g6a5w338e

106. Caffeine Hydrous

107. 1gfz

108. Caffeine, Bioxtra

109. Tnp00310

110. Monohydrate Caffeine

111. Respia (tn)

112. 1-methyl-theobromine

113. 7-methyl Theophylline

114. Cafergot (salt/mix)

115. 1,7-trimethylxanthine

116. Spectrum_001301

117. 1l5q

118. 1l7x

119. 2a3b

120. 3g6m

121. 3,7-dihydro-1,3,7-trimethyl-1h-purine

122. Caffeine [fhfi]

123. Caffeine [hsdb]

124. Caffeine [iarc]

125. Caffeine [inci]

126. Caffeine [fcc]

127. Xanthine,3,7-trimethyl

128. Caffeine [ii]

129. Caffeine [mi]

130. Theine, Methyltheobromine

131. Caffeine [vandf]

132. Caffeinum [hpus]

133. 1,3,7-trimethylxantine

134. Spectrum2_001261

135. Spectrum3_000321

136. Spectrum4_001782

137. Spectrum5_000423

138. Lopac-c-0750

139. Caffeine [mart.]

140. Bmse000206

141. Caffeine [usp-rs]

142. Caffeine [who-dd]

143. Caffeine [who-ip]

144. Molmap_000054

145. Probes1_000150

146. Probes2_000128

147. C 0750

148. Ec 200-362-1

149. Schembl5671

150. Anhydrous Caffeine (jp17)

151. Nciopen2_008255

152. Bidd:pxr0172

153. Lopac0_000228

154. 1, 3, 7-trimethylxanthine

155. Bspbio_001921

156. Gtpl407

157. Kbiogr_002325

158. Kbioss_001781

159. 1,3,7-trimethyl-1,3,7-trihydropurine-2,6-dione

160. 5-26-13-00558 (beilstein Handbook Reference)

161. 95789-13-2

162. Mls001055341

163. Mls001056714

164. Mls001066409

165. Bidd:er0554

166. Bidd:gt0632

167. Divk1c_000730

168. Spectrum1500155

169. Cu-01000012617-3

170. Spbio_001222

171. Caffeine [orange Book]

172. Esgic Component Caffeine

173. Triad Component Caffeine

174. Megxp0_001350

175. Zinc1084

176. Caffeine [ep Monograph]

177. Dimenhydrinate Impurity C

178. Femcet Component Caffeine

179. Trezix Component Caffeine

180. 1,3,7-trimethyl-2,6-dioxo-1,2,3,6-tetrahydropurine

181. Anhydrous Caffeine [jan]

182. Caffeine [usp Monograph]

183. Component Of Dilone (salt/mix)

184. Dtxsid0020232

185. 1,7-trimethyl-2,6-dioxopurine

186. Acon1_000085

187. Anoquan Component Caffeine

188. Bdbm10849

189. Hms502e12

190. Kbio1_000730

191. Kbio2_001781

192. Kbio2_004349

193. Kbio2_006917

194. Kbio3_001141

195. Caffeine 1.0 Mg/ml In Methanol

196. Coffeinum [who-ip Latin]

197. Nsc5036

198. Cafergot Component Caffeine

199. Caffeine, Powder, Reagentplus(r)

200. Component Of Percodan (salt/mix)

201. Excedrin Component Caffeine

202. Fioricet Component Caffeine

203. Fiorinal Component Caffeine

204. Migergot Component Caffeine

205. Ninds_000730

206. Norgesic Component Caffeine

207. Wigraine Component Caffeine

208. Bio1_000473

209. Bio1_000962

210. Bio1_001451

211. Caffeine Component Of Esgic

212. Caffeine Component Of Triad

213. Dhc Plus Component Caffeine

214. Hms1920i09

215. Hms2091o11

216. Hms2232m13

217. Hms3260n17

218. Hms3372j18

219. Hms3435f10

220. Hms3715d13

221. Pharmakon1600-01500155

222. Invagesic Component Caffeine

223. Lanorinal Component Caffeine

224. Nodoz Caplets And Chewable Tablets

225. Caffeine 10 Microg/ml In Methanol

226. Caffeine Anhydrous [who-ip]

227. Caffeine Component Of Femcet

228. Cs-m0795

229. Caffeine Component Of Anoquan

230. Tox21_201685

231. Tox21_300010

232. Tox21_500228

233. Caffeine (1,3,7-trimethylxanthine)

234. Caffeine 100 Microg/ml In Methanol

235. Ccg-38825

236. Nsc755917

237. Orphengesic Component Caffeine

238. Pdsp1_001016

239. Pdsp1_001235

240. Pdsp2_001000

241. Pdsp2_001219

242. Stk177283

243. Caffeine Component Of Cafergot

244. Caffeine Component Of Dhc Plus

245. Caffeine Component Of Excedrin

246. Caffeine Component Of Fioricet

247. Caffeine Component Of Fiorinal

248. Caffeine Component Of Migergot

249. Caffeine Component Of Norgesic

250. Caffeine Component Of Wigraine

251. Propoxyphene Compound 65 (salt/mix)

252. Synalgos-dc Component Caffeine

253. Akos000121334

254. Caffeine Component Of Invagesic

255. Caffeine Component Of Lanorinal

256. 5-26-13-00558 (beilstein)

257. Bayer Select Headache Pain (salt/mix)

258. Caffeine, Anhydrous, 99%, Fcc, Fg

259. Db00201

260. Lp00228

261. Nsc-755917

262. Sdccgmls-0064595.p001

263. Sdccgmls-0064595.p002

264. Sdccgsbi-0050216.p005

265. Caffeine Component Of Orphengesic

266. Idi1_000730

267. Medigesic Plus Component Caffeine

268. Synalgos-dc-a Component Caffeine

269. 3,3,7-trimethyl-1h-purine-2,6-dione

270. Caffeine Component Of Synalgos-dc

271. Darvon Compound Component Caffeine

272. Invagesic Forte Component Caffeine

273. Ncgc00015208-01

274. Ncgc00015208-02

275. Ncgc00015208-03

276. Ncgc00015208-04

277. Ncgc00015208-05

278. Ncgc00015208-06

279. Ncgc00015208-07

280. Ncgc00015208-08

281. Ncgc00015208-10

282. Ncgc00015208-11

283. Ncgc00015208-12

284. Ncgc00015208-13

285. Ncgc00015208-14

286. Ncgc00015208-15

287. Ncgc00015208-16

288. Ncgc00015208-17

289. Ncgc00015208-18

290. Ncgc00015208-20

291. Ncgc00015208-29

292. Ncgc00090699-01

293. Ncgc00090699-02

294. Ncgc00090699-03

295. Ncgc00090699-04

296. Ncgc00090699-05

297. Ncgc00090699-06

298. Ncgc00090699-07

299. Ncgc00090699-08

300. Ncgc00090699-09

301. Ncgc00168808-01

302. Ncgc00168808-02

303. Ncgc00254057-01

304. Ncgc00259234-01

305. Ncgc00260913-01

306. Ac-12774

307. As-15340

308. Caffeine, Saj Special Grade, >=98.5%

309. Component Of P-a-c Compound (salt/mix)

310. Caffeine Component Of Synalgos-dc-a

311. Component Of A.s.a. Compound (salt/mix)

312. Orphengesic Forte Component Caffeine

313. Sbi-0050216.p004

314. Caffeine Component Of Medigesic Plus

315. Db-023002

316. Wln: T56 Bn Dn Fnvnvj B1 F1 H1

317. Caffeine Component Of Darvon Compound

318. Caffeine Component Of Invagesic Forte

319. Eu-0100228

320. Ft-0664195

321. N1379

322. N2379

323. Theophylline Impurity A [ep Impurity]

324. Caffeine Component Of Orphengesic Forte

325. Bim-0050216.0001

326. C07481

327. D00528

328. Dimenhydrinate Impurity C [ep Impurity]

329. Pentoxifylline Impurity F [ep Impurity]

330. Q60235

331. 1,3,7-trimethyl-3,7-dihydropurine-2,6-dione

332. 1h-purine-2, 3,7-dihydro-1,3,7-trimethyl-

333. Ab00051930-09

334. Ab00051930_10

335. Caffeine, Purum, Anhydrous, >=99.0% (hplc)

336. 3,7-dihydro-1,3,7-trimethyl-1h-purine (9ci)

337. Caffeine, Anhydrous, Tested According To Ph.eur.

338. L000155

339. 3,7-dihydro-1,3,7-trimethyl-1h-purin-2,6-dion

340. Caffeine, Sigma Reference Standard, Vial Of 250 Mg

341. Sr-01000075187-1

342. Sr-01000075187-4

343. Sr-01000075187-7

344. Sr-01000075187-8

345. Brd-k02404261-001-02-7

346. Brd-k02404261-001-03-5

347. Brd-k02404261-001-07-6

348. Caffeine, Certified Reference Material, Tracecert(r)

349. Caffeine, Meets Usp Testing Specifications, Anhydrous

350. Melting Point Standard 235-237c, Analytical Standard

351. 1,3,7-trimethyl-3,7-dihydro-1h-purine-2,6-dione #

352. Caffeine, British Pharmacopoeia (bp) Reference Standard

353. Caffeine, European Pharmacopoeia (ep) Reference Standard

354. F3371-0262

355. Theophylline Monohydrate Impurity A [ep Impurity]

356. Z112207564

357. Caffeine 2000 Microg/ml In Water:methanol (81:19 G/g)

358. 07e4fb58-fd79-4175-8e3d-05bf96954522

359. 3,7-dihydro-1,3,7-trimethyl-1h-purin-2,6-dion (coffein)

360. Caffeine Solution, Analytical Standard, 1.0 Mg/ml In Methanol

361. Caffeine, United States Pharmacopeia (usp) Reference Standard

362. Caffeine, Pharmaceutical Secondary Standard; Certified Reference Material

363. Caffeine For System Suitability, European Pharmacopoeia (ep) Reference Standard

364. Caffeine Melting Point Standard, United States Pharmacopeia (usp) Reference Standard

365. Caffeine Solution, 1.0 Mg/ml In Methanol, Ampule Of 1 Ml, Certified Reference Material

366. 114303-55-8

367. Caffeine Melting Point Standard, Pharmaceutical Secondary Standard; Certified Reference Material

368. Caffeine, Pharmagrade, Ep, Manufactured Under Appropriate Gmp Controls For Pharma Or Biopharmaceutical Production

369. Mettler-toledo Calibration Substance Me 18872, Caffeine, Analytical Standard, For The Calibration Of The Thermosystem 900, Traceable To Primary Standards (lgc)

2.3.3 Other Synonyms

1. Caffeine Mixture With Ergotamine

2. Ergotamine Mixture With Caffeine

3. Cafergamine

2.4 Create Date
2004-09-16
3 Chemical and Physical Properties
Molecular Weight 194.19 g/mol
Molecular Formula C8H10N4O2
XLogP3-0.1
Hydrogen Bond Donor Count0
Hydrogen Bond Acceptor Count3
Rotatable Bond Count0
Exact Mass194.08037557 g/mol
Monoisotopic Mass194.08037557 g/mol
Topological Polar Surface Area58.4 Ų
Heavy Atom Count14
Formal Charge0
Complexity293
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 NameCafcit
PubMed HealthCaffeine Citrate (By mouth)
Drug ClassesStimulant, Respiratory
Active IngredientCaffeine citrate
Dosage FormSolution
RouteIntravenous; Oral
Strengtheq 30mg base/3ml (eq 10mg base/ml)
Market StatusPrescription
CompanyEurohlth Intl

2 of 6  
Drug NameLanorinal
PubMed HealthAspirin/Caffeine/Dihydrocodeine (By mouth)
Drug ClassesAnalgesic, Opioid/Salicylate, Aspirin Combination
Active Ingredientbutalbital; caffeine; Aspirin
Dosage FormCapsule
RouteOral
Strength50mg; 325mg; 40mg
Market StatusPrescription
CompanyLannett

3 of 6  
Drug NameSynalgos-dc
Active Ingredientdihydrocodeine bitartrate; caffeine; Aspirin
Dosage FormCapsule
RouteOral
Strength30mg; 356.4mg; 16mg
Market StatusPrescription
CompanyCaraco

4 of 6  
Drug NameCafcit
PubMed HealthCaffeine Citrate (By mouth)
Drug ClassesStimulant, Respiratory
Active IngredientCaffeine citrate
Dosage FormSolution
RouteIntravenous; Oral
Strengtheq 30mg base/3ml (eq 10mg base/ml)
Market StatusPrescription
CompanyEurohlth Intl

5 of 6  
Drug NameLanorinal
PubMed HealthAspirin/Caffeine/Dihydrocodeine (By mouth)
Drug ClassesAnalgesic, Opioid/Salicylate, Aspirin Combination
Active Ingredientbutalbital; caffeine; Aspirin
Dosage FormCapsule
RouteOral
Strength50mg; 325mg; 40mg
Market StatusPrescription
CompanyLannett

6 of 6  
Drug NameSynalgos-dc
Active Ingredientdihydrocodeine bitartrate; caffeine; Aspirin
Dosage FormCapsule
RouteOral
Strength30mg; 356.4mg; 16mg
Market StatusPrescription
CompanyCaraco

4.2 Therapeutic Uses

Central Nervous System Stimulants; Phosphodiesterase Inhibitors; Purinergic P1 Receptor Antagonists

National Library of Medicine's Medical Subject Headings. Caffeine. Online file (MeSH, 2014). Available from, as of January 30, 2014: https://www.nlm.nih.gov/mesh/2014/mesh_browser/MBrowser.html


Caffeine is used orally as a mild CNS stimulant to aid in staying awake and to restore mental alertness in fatigued patients.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2567


Apnea of prematurity. Caffeine citrate is used iv or orally in the short-term (10-12 days) treatment of apnea of prematurity in neonates who are between 28 and less than 33 weeks of gestational age. Caffeine is designated an orphan drug by the US Food and Drug Administration (FDA) for use in apnea in premature neonates.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2567


Caffeine is used in combination with ergotamine tartrate to abort vascular headaches such as migraine and cluster headaches (histamine cephalalgia).

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2567


For more Therapeutic Uses (Complete) data for CAFFEINE (11 total), please visit the HSDB record page.


4.3 Drug Warning

Because it has been suggested that caffeine may promote gastric ulceration, the drug should be used cautiously in patients with a history of peptic ulcer. Because of its suspected arrhythmogenic potential, it is generally recommended that caffeine be avoided in patients with symptomatic cardiac arrhythmias and/or palpitations and during the first several days to weeks after an acute myocardial infarction

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2568


Prior to initiation of caffeine citrate therapy, baseline serum concentrations of caffeine should be measured in neonates previously treated with theophylline, since preterm neonates metabolize theophylline to caffeine. Similarly, baseline serum concentrations of caffeine should be measured in infants born to mothers who consumed caffeine prior to delivery since caffeine readily crosses the placenta. Serious toxicity has been reported when serum caffeine concentrations exceed 50 ug/mL. /Caffeine citrate/

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2568


In clinical trials reported in the literature, cases of hypoglycemia and hyperglycemia have been reported in patients receiving caffeine; therefore, blood glucose concentration may need to be monitored periodically in neonates receiving caffeine citrate. /Caffeine citrate/

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2568


During the placebo-controlled trial of caffeine citrate establishing efficacy in the US for apnea of prematurity, 6 cases of necrotizing enterocolitis developed among the 85 neonates studied, 3 cases of which were fatal. Five of the 6 neonates had been randomized to treatment with or had been exposed to caffeine citrate. Reports in the literature have raised the possibility of an association betwen the use of methylxanthines and the development of necrotizing enterocolitis, although a causal relationship between methylxanthine use and the development of necrotizing enterocolitis have not been established. Therefore, as with all premature neonates, patients being treated with caffeine citrate should be monitored carefully for the development of necrotizing enterocolitis. /Caffeine citrate/

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2568


For more Drug Warnings (Complete) data for CAFFEINE (25 total), please visit the HSDB record page.


4.4 Minimum/Potential Fatal Human Dose

In adults, iv doses of 57 mg/kg and oral doses of 18-50 g have been fatal.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


In one 5-year-old patient, death occurred following oral ingestion of approximately 3 g of caffeine.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


4.5 Drug Indication

Caffeine is indicated for the short term treatment of apnea of prematurity in infants and off label for the prevention and treatment of bronchopulmonary dysplasia caused by premature birth. In addition, it is indicated in combination with sodium benzoate to treat respiratory depression resulting from an overdose with CNS depressant drugs. Caffeine has a broad range of over the counter uses, and is found in energy supplements, athletic enhancement products, pain relief products, as well as cosmetic products.


FDA Label


5 Pharmacology and Biochemistry
5.1 Pharmacology

Caffeine stimulates the central nervous system (CNS), heightening alertness, and sometimes causing restlessness and agitation. It relaxes smooth muscle, stimulates the contraction of cardiac muscle, and enhances athletic performance. Caffeine promotes gastric acid secretion and increases gastrointestinal motility. It is often combined in products with analgesics and ergot alkaloids, relieving the symptoms of migraine and other types of headaches. Finally, caffeine acts as a mild diuretic.


5.2 MeSH Pharmacological Classification

Phosphodiesterase Inhibitors

Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases. (See all compounds classified as Phosphodiesterase Inhibitors.)


Purinergic P1 Receptor Antagonists

Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS. (See all compounds classified as Purinergic P1 Receptor Antagonists.)


Central Nervous System Stimulants

A loosely defined group of drugs that tend to increase behavioral alertness, agitation, or excitation. They work by a variety of mechanisms, but usually not by direct excitation of neurons. The many drugs that have such actions as side effects to their main therapeutic use are not included here. (See all compounds classified as Central Nervous System Stimulants.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
CAFFEINE
5.3.2 FDA UNII
3G6A5W338E
5.3.3 Pharmacological Classes
Central Nervous System Stimulation [PE]; Methylxanthine [EPC]; Xanthines [CS]; Central Nervous System Stimulant [EPC]
5.4 ATC Code

N06BC01

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


D - Dermatologicals

D11 - Other dermatological preparations

D11A - Other dermatological preparations

D11AX - Other dermatologicals

D11AX26 - Caffeine


N - Nervous system

N06 - Psychoanaleptics

N06B - Psychostimulants, agents used for adhd and nootropics

N06BC - Xanthine derivatives

N06BC01 - Caffeine


5.5 Absorption, Distribution and Excretion

Absorption

Caffeine is rapidly absorbed after oral or parenteral administration, reaching peak plasma concentration within 30 minutes to 2 hours after administration. After oral administration, onset of action takes place within 45 to 1 hour. Food may delay caffeine absorption. The peak plasma level for caffeine ranges from 6-10mg/L. The absolute bioavailability is unavailable in neonates, but reaches about 100% in adults.


Route of Elimination

The major metabolites of caffeine can be found excreted in the urine. About 0.5% to 2% of a caffeine dose is found excreted in urine, as it because it is heavily absorbed in the renal tubules.


Volume of Distribution

Caffeine has the ability to rapidly cross the blood-brain barrier. It is water and fat soluble and distributes throughout the body. Caffeine concentrations in the cerebrospinal fluid of preterm newborns are similar to the concentrations found in the plasma. The mean volume of distribution of caffeine in infants is 0.8-0.9 L/kg and 0.6 L/kg in the adult population.


Clearance

The clearance of caffeine varies, but on average, is about 0.078L/kg/h (1.3mL/min/kg).


World-wide, many fetuses and infants are exposed to methylxanthines via maternal consumption of coffee and other beverages containing these substances. Methylxanthines (caffeine, theophylline and aminophylline) are also commonly used as a medication for apnea of prematurity. ... Methylxanthines readily passes the placenta barrier and enters all tissues and thus may affect the fetus/newborn at any time during pregnancy or postnatal life, given that the effector systems are mature. ...

PMID:20859804 Aden U; Handb Exp Pharmacol (200): 373-89 (2011)


Caffeine and citrated caffeine are well absorbed following oral administration. Absorption of caffeine following oral administration may be more rapid than that following IM injection of caffeine and sodium benzoate. Absorption following rectal administration of caffeine in suppositories may be slow and erratic. ... Following oral administration of 100 mg of caffeine (as coffee), peak plasma concentrations of about 1.5-1.8 ug/mL are reached after 50-75 minutes.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


After oral administration of 10 mg caffeine base/kg to preterm neonates, the peak plasma concentration for caffeine ranged from 6-10 mg/L and the mean time to reach peak concentration /Tmax/ ranged from 30 minutes to 2 hours. The /Tmax/ was not affected by formula feeding.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


Caffeine is rapidly distributed into body tissues, readily crossing the placenta and blood-brain barrier. Caffeine concentration in the CSF fluid of preterm neonates approximates the plasma concentration. The mean volume of distribution of caffeine in infants (0.8-0.9 L/kg) is slightly higher than that in adults (0.6 L/kg). ... Caffeine has been shown to distribute into milk in a milk-to-serum concentration ratio of 0.5-0.76.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


For more Absorption, Distribution and Excretion (Complete) data for CAFFEINE (11 total), please visit the HSDB record page.


5.6 Metabolism/Metabolites

Caffeine metabolism occurs mainly in the liver via the cytochrome CYP1A2 enzyme. The products of caffeine metabolism include paraxanthine, theobromine, and theophylline. The first step of caffeine metabolism is demethylation, yielding paraxanthine (a major metabolite), followed by theobromine, and theophylline, which are both minor metabolites. They are then excreted in urine as urates after additional metabolism. The enzymes xanthine oxidase and N-acetyltransferase 2 (NAT2) also participate in the metabolism of caffeine.


Caffeine is metabolized by the cytochrome P-450 (CYP) enzyme system, principally by isoenzyme 1A2. Therefore, caffeine has the potential to interact with drugs that are metabolized by CYP1A2 or with drugs that induce or inhibit this isoenzyme.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


In adults, the drug is rapidly metabolized in the liver to 1-methyluric acid, 1-methylxanthine, and 7-methylxanthine.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


Interconversion between caffeine and theophylline has been reported in preterm neonates...

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


In-vivo and in-vitro experiments showed a progressive increase in the activity of the hepatic microsomal enzymes that metabolize caffeine during neonatal development. In beagle puppies, change in caffeine clearance was determined by the rate of maturation of caffeine-7-demethylase. Caffeine is eliminated in animals by biotransformation in the liver to dimethylxanthines, dimethyl- and monomethyluric acids and uracil derivatives; important quantitative differences have been demonstrated in the formation and elimination of metabolites in rats, mice and Chinese hamsters. These differences are even more important in monkeys, where caffeine is almost completely metabolized to theophylline. ... Some species-dependent metabolites have been identified. Trimethylallantoin was first reported in rats. A ... derivative of paraxanthine was found in mice and identified as the 3-beta-D-glucuronide of paraxanthine. Methylated ureas and sulfur-containing derivatives found in urine in trace amounts are produced by the intestinal flora. In contrast, the acetylated uracil derivative, 5-acetylamino-6-formylamino-3-methyluracil, one of the most important caffeine metabolites in humans, has not been identified in rodents or other animal species. Other uracil derivatives produced from caffeine, theobromine and paraxanthine in rats were found in human urine. In rats, the hepatic demethylation of caffeine shows an age-related decline, resulting in a greatly increased elimination half-time in older adult rats.

IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V51 322 (1991)


Caffeine metabolism is qualitatively relatively similar in animals and humans ... . The main metabolic pathways are: demethylation and hydroxylation of the 8-position leading to the formation of the respective uracil and uric acid derivatives. There are, however, some quantitative differences in the metabolic profile. Humans are characterized by the importance of 3-methyl demethylation leading to the formation of paraxanthine and especially metabolites thereof through subsequent metabolic steps. The main urinary metabolites in humans are 1-methyluric acid, 1-methylxanthine, 5-acetylamino-6-formylamino-3- methyluracil (not found in rats and mice), 1,7-dimethyluric acid and paraxanthin. In rats and mice, the metabolism of caffeine is predominantly via theobromine and theophylline. The main urinary metabolites are 1,3-dimethyluracil, paraxanthine, trimethyluric acid, theophylline, and theobromine. Caffeine metabolism decreases during pregnancy, resulting in higher serum concentrations.

OECD SIDS for Caffeine (CAS 58-08-2); Available from, as of January 9, 2014: https://www.inchem.org/documents/sids/sids/CAFEINE.pdf


Caffeine has known human metabolites that include 1,3,7-Trimethyluric acid, Theobromine, paraxanthine, and theophylline.

S73 | METXBIODB | Metabolite Reaction Database from BioTransformer | DOI:10.5281/zenodo.4056560


5.7 Biological Half-Life

In an average-sized adult or child above the age of 9, the half-life of caffeine is approximately 5 hours. Various characteristics and conditions can alter caffeine half-life. It can be reduced by up to 50% in smokers. Pregnant women show an increased half-life of 15 hours or higher, especially in the third trimester. The half-life in newborns is prolonged to about 8 hours at full-term and 100 hours in premature infants, likely due to reduced ability to metabolize it. Liver disease or drugs that inhibit CYP1A2 can increase caffeine half-life.


Elimination 1/2 life in adults = 2.5-4.5 hours; [Reference #1]


Caffeine has a plasma half-life (t1/2) of 3 to 5 hours in adults. In one study, when administered to pregnant women prior to delivery, caffeine had a prolonged mean half-life of 80 hours in neonates after delivery.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


Mean half-life /T 1/2/ and fraction excreted unchanged in urine of caffeine in infants have been shown to be inversely related to gestational/postconceptual age. In neonates, the /T 1/2/ is approximately 3-4 days...

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


The half-time for caffeine is 0.7-1.0 hr in rats and mice, 1-1.6 hr in rabbits, 3-5 hr in monkeys, 4-4.3 hr in dogs and 11-12 hr in baboons.

IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work). Available at: https://monographs.iarc.fr/ENG/Classification/index.php, p. V51 321 (1991)


/The authors/ studied 17 preterm infants receiving caffeine, and measured their plasma levels of caffeine and the theophylline metabolite by high-pressure liquid chromatography. The half-life was calculated by computer analysis using the least-square method. The mean gestational age of our patients was 29.7 +/- 1.9 weeks (mean +/- SD) and they were studied at 20.7 +/- 6.6 days (mean +/- SD) postnatal age. The caffeine half-life was 52.03 +/- 23.87 hr (means +/- SD) and the theophylline half-life was 77.04 +/- 65.01 hr (mean +/- SD).

PMID:2714159 Pearlman SA et al; Dev Pharmacol Ther 12 (2): 65-9 (1989)


5.8 Mechanism of Action

The mechanism of action of caffeine is complex, as it impacts several body systems, which are listed below. The effects as they relate to various body systems are described as follows: **General and cellular actions** Caffeine exerts several actions on cells, but the clinical relevance is poorly understood. One probable mechanism is the inhibition of nucleotide phosphodiesterase enzymes, adenosine receptors, regulation of calcium handling in cells, and participates in adenosine receptor antagonism. Phosphodiesterase enzymes regulate cell function via actions on second messengers cAMP and cGMP. This causes lipolysis through activation of hormone-sensitive lipases, releasing fatty acids and glycerol. **Respiratory** The exact mechanism of action of caffeine in treating apnea related to prematurity is unknown, however, there are several proposed mechanisms, including respiratory center stimulation in the central nervous system, a reduced threshold to hypercapnia with increased response, and increased consumption of oxygen, among others. The blocking of the adenosine receptors enhances respiratory drive via an increase in brain medullary response to carbon dioxide, stimulating ventilation and respiratory drive, while increasing contractility of the diaphragm. **Central nervous system** Caffeine demonstrates antagonism of all 4 adenosine receptor subtypes (A1, A2a, A2b, A3) in the central nervous system. Caffeine's effects on alertness and combatting drowsiness are specifically related to the antagonism of the A2a receptor. **Renal system** Caffeine has diuretic effects due to is stimulatory effects on renal blood flow, increase in glomerular filtration, and increase in sodium excretion. **Cardiovascular system** Adenosine receptor antagonism at the A1 receptor by caffeine stimulates inotropic effects in the heart. Blocking of adenosine receptors promotes catecholamine release, leading to stimulatory effects occurring in the heart and the rest of the body. In the blood vessels, caffeine exerts direct antagonism of adenosine receptors, causing vasodilation. It stimulates the endothelial cells in the blood vessel wall to release nitric oxide, potentiating blood vessel relaxation. Catecholamine release, however, antagonizes this and exerts inotropic and chronotropic effects on the heart, ultimately leading to vasoconstriction. Finally, caffeine is shown to raise systolic blood pressure measurements by 5 to 10 mmHg when it is not taken regularly, versus no effect in those who consume it regularly. The vasoconstricting effects of caffeine are beneficial in migraines and other types of headache, which are normally caused by vasodilation in the brain.


Caffeine competitively inhibits phosphodiesterase, the enzyme that degrades cyclic 3',5'-adenosine monophosphate (AMP). Increased levels of intracellular cyclic AMP mediate most of caffeine's pharmacologic actions.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


Caffeine stimulates all levels of the CNS... Caffeine's cortical effects are milder and of shorter duration than those of amphetamines. In slightly larger doses, caffeine stimulates medullary, vagal, vasomotor, and respiratory centers, promoting bradycardia, vasoconstriction, and increased respiratory rate.

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569


Caffeine constricts cerebral vasculature. In contrast, the drug directly dilates peripheral blood vessels...

American Society of Health-System Pharmacists 2013; Drug Information 2013. Bethesda, MD. 2013, p. 2569