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2D Structure
Also known as: 81103-11-9, Biaxin, 6-o-methylerythromycin, Klaricid, 6-o-methylerythromycin a, Abbott-56268
Molecular Formula
C38H69NO13
Molecular Weight
748.0  g/mol
InChI Key
AGOYDEPGAOXOCK-KCBOHYOISA-N
FDA UNII
H1250JIK0A

A semisynthetic macrolide antibiotic derived from ERYTHROMYCIN that is active against a variety of microorganisms. It can inhibit protein synthesis in bacteria by reversibly binding to the 50S ribosomal subunits. This inhibits the translocation of aminoacyl transfer-RNA and prevents peptide chain elongation.
Clarithromycin is a Macrolide Antimicrobial. The mechanism of action of clarithromycin is as a Cytochrome P450 3A4 Inhibitor, and Cytochrome P450 3A Inhibitor, and P-Glycoprotein Inhibitor.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
(3R,4S,5S,6R,7R,9R,11R,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-7-methoxy-3,5,7,9,11,13-hexamethyl-oxacyclotetradecane-2,10-dione
2.1.2 InChI
InChI=1S/C38H69NO13/c1-15-26-38(10,45)31(42)21(4)28(40)19(2)17-37(9,47-14)33(52-35-29(41)25(39(11)12)16-20(3)48-35)22(5)30(23(6)34(44)50-26)51-27-18-36(8,46-13)32(43)24(7)49-27/h19-27,29-33,35,41-43,45H,15-18H2,1-14H3/t19-,20-,21+,22+,23-,24+,25+,26-,27+,29-,30+,31-,32+,33-,35+,36-,37-,38-/m1/s1
2.1.3 InChI Key
AGOYDEPGAOXOCK-KCBOHYOISA-N
2.1.4 Canonical SMILES
CCC1C(C(C(C(=O)C(CC(C(C(C(C(C(=O)O1)C)OC2CC(C(C(O2)C)O)(C)OC)C)OC3C(C(CC(O3)C)N(C)C)O)(C)OC)C)C)O)(C)O
2.1.5 Isomeric SMILES
CC[C@@H]1[C@@]([C@@H]([C@H](C(=O)[C@@H](C[C@@]([C@@H]([C@H]([C@@H]([C@H](C(=O)O1)C)O[C@H]2C[C@@]([C@H]([C@@H](O2)C)O)(C)OC)C)O[C@H]3[C@@H]([C@H](C[C@H](O3)C)N(C)C)O)(C)OC)C)C)O)(C)O
2.2 Other Identifiers
2.2.1 UNII
H1250JIK0A
2.3 Synonyms
2.3.1 MeSH Synonyms

1. 6-o-methylerythromycin

2. A 56268

3. A-56268

4. A56268

5. Biaxin

6. Te 031

7. Te-031

8. Te031

2.3.2 Depositor-Supplied Synonyms

1. 81103-11-9

2. Biaxin

3. 6-o-methylerythromycin

4. Klaricid

5. 6-o-methylerythromycin A

6. Abbott-56268

7. Clarithromycine

8. Clathromycin

9. Macladin

10. Klacid

11. Veclam

12. Erythromycin, 6-o-methyl-

13. Mavid

14. Naxy

15. A-56268

16. Te-031

17. Clarith

18. Cyllind

19. Kofron

20. Zeclar

21. Clarithromycinum

22. Clarithromycin Identity

23. Biaxin Xl

24. Te031

25. Nsc-758704

26. Prevpac

27. Chebi:3732

28. H1250jik0a

29. (3r,4s,5s,6r,7r,9r,11r,12r,13s,14r)-6-(((2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2h-pyran-2-yl)oxy)-14-ethyl-12,13-dihydroxy-4-(((2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyltetrahydro-2h-pyran-2-yl)oxy)-7-methoxy-3,5,7,9,11,13-hexamethyloxacyclotetradecane-2,10-dione

30. Claritromicina

31. Abbotic

32. Astromen

33. Bicrolid

34. Clacine

35. Clambiotic

36. Claribid

37. Claricide

38. Claridar

39. Claripen

40. Fromilid

41. Heliclar

42. Klaciped

43. Mabicrol

44. Clacee

45. Clacid

46. Clarem

47. Crixan

48. Cyllid

49. Klabax

50. Klarid

51. Klarin

52. Maclar

53. Helas

54. Adel

55. Biaxin Filmtab

56. Klax

57. Biaxin Hp

58. Biaxin Xl Filmtab

59. Klaricid Pediatric

60. (3r,4s,5s,6r,7r,9r,11r,12r,13s,14r)-6-[(2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-7-methoxy-3,5,7,9,11,13-hexamethyl-oxacyclotetradecane-2,10-dione

61. Cla

62. Clarithromycin Extended Release

63. Drg-0099

64. Klaricid H.p.

65. Cty

66. Smr000466382

67. Clarithromycine [inn-french]

68. Clarithromycinum [inn-latin]

69. Claritromicina [inn-spanish]

70. Sr-05000001992

71. Clarithromycin (biaxin, Klacid)

72. Clarithromycina

73. Unii-h1250jik0a

74. Clarosip

75. Ccris 8833

76. Klaricid Xl

77. Hsdb 8055

78. (14r)-14-hydroxyclarithromycin

79. (3r,4s,5s,6r,7r,9r,11r,12r,13s,14r)-6-[(2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyl-tetrahydropyran-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyl-tetrahydropyran-2-yl]oxy-7-methoxy-3,5,7,9,11,13-hexamethyl-oxacyclotetradecane-2,10-dione

80. (3r,4s,5s,6r,7r,9r,11r,12r,13s,14r)-6-[(2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-7-methoxy

81. Clarithromycin,(s)

82. Biaxin (tn)

83. Spectrum_000089

84. Cpd000466382

85. Clarithromycin [usan:usp:inn:ban:jan]

86. Specplus_000559

87. 6-o-methyl Erythromycin

88. O(6)-methylerythromycin

89. Spectrum2_001668

90. Spectrum3_001667

91. Spectrum4_000629

92. Spectrum5_001729

93. 6-0-methylerythromycin A

94. A56268

95. Clarithromycin [mi]

96. Chembl1741

97. Clarithromycin [inn]

98. Clarithromycin [jan]

99. Schembl38125

100. Bspbio_003453

101. Kbiogr_001218

102. Kbioss_000509

103. Mls000759516

104. Mls001201751

105. Mls001424066

106. Bidd:gt0200

107. Clarithromycin [vandf]

108. Divk1c_006655

109. Spectrum1504231

110. Spbio_001855

111. Clarithromycin [mart.]

112. Lactoferrin B & Clarithromycin

113. Lactoferrin H & Clarithromycin

114. Clarithromycin [usp-rs]

115. Clarithromycin [who-dd]

116. Dtxsid3022829

117. Clarithromycin & Interleukin-12

118. Clm & Il-12

119. Gtpl10903

120. Kbio1_001599

121. Kbio2_000509

122. Kbio2_003077

123. Kbio2_005645

124. Kbio3_002673

125. Anx-015

126. Sdp-015

127. Clarithromycin (jp17/usp/inn)

128. Clarithromycin, >=95% (hplc)

129. Clarithromycin, >=98% (hplc)

130. Hms1922h09

131. Hms2051g18

132. Hms2090o11

133. Hms2094m05

134. Hms2231a08

135. Hms3715j17

136. Pharmakon1600-01504231

137. Clarithromycin [orange Book]

138. Bdbm50404044

139. Ccg-39086

140. Clarithromycin [ep Monograph]

141. Clarithromycin [usp Impurity]

142. Lmpk04000014

143. Nsc758704

144. S2555

145. Zinc85534098

146. Clarithromycin [usp Monograph]

147. Akos015894242

148. Prevpac Component Clarithromycin

149. Cs-2576

150. Db01211

151. Nc00140

152. Nsc 758704

153. Clarithromycin Identity [usp-rs]

154. Ncgc00178054-01

155. Ncgc00178054-06

156. Clarithromycin 100 Microg/ml In Methanol

157. Clarithromycin Component Of Prevpac

158. Hy-17508

159. Sbi-0206716.p001

160. Clarithromycin 100 Microg/ml In Acetonitrile

161. C06912

162. D00276

163. F14975

164. Ab00053394-10

165. Ab00053394-12

166. Ab00053394-13

167. Ab00053394_14

168. Ab00053394_15

169. 103c119

170. A840042

171. Q118551

172. Q-200870

173. Sr-05000001992-1

174. Sr-05000001992-2

175. Brd-k49668410-001-07-1

176. Brd-k49668410-001-18-8

177. Clarithromycin, European Pharmacopoeia (ep) Reference Standard

178. Clarithromycin, United States Pharmacopeia (usp) Reference Standard

179. Clarithromycin Identity, United States Pharmacopeia (usp) Reference Standard

180. Clarithromycin, Ready Made Solution, 50 Mg/ml In Dmso, 0.2 Mum Filtered

181. Clarithromycin For Peak Identification, European Pharmacopoeia (ep) Reference Standard

182. Clarithromycin, Pharmaceutical Secondary Standard; Certified Reference Material

183. (3r,4s,5r,6r,7r,9r,11r,12r,13s,14r)-6-[(2s,3r,4r,6r)-4-(dimethylamino)-3-hydroxy-6-methyl-tetrahydropyran-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyl-tetrahydropyran-2-yl]oxy-7-methoxy-3,5,7,9,11,13-hexamethyl-oxacy

184. (3r,4s,5s,6r,7r,9r,11r,12r,13s,14r)-6-((2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2h-pyran-2-yloxy)-14-ethyl-12,13-dihydroxy-4-((2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyltetrahydro-2h-pyran-2-yloxy)-7-methoxy-3,5,7,9,11,13-hexamethyloxacyclotetradecane-2,10-dione

185. (3r,4s,5s,6r,7r,9r,11r,12r,13s,14r)-6-[(2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-7-methoxy-3,5,7,9,11,13-hexamethyl-oxacyclotetradecane-2,10-dion

186. (3r,4s,5s,6r,7r,9r,11r,12r,13s,14r)-6-{[(2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2h-pyran-2-yl]oxy}-14-ethyl-12,13-dihydroxy-4-{[(2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyltetrahydro-2h-pyran-2-yl]oxy}-7-methoxy-3,5,7,9,11,13-hexamethyloxacyclotetradecane-2,10-dione (non-preferred Name)

187. (3r,4s,5s,6r,7r,9r,11s, 12r,13s,14s)-6-{[(2s,3r,4s,6r)- 4-dimethylamino-3-hydroxy-6-methyloxan-2-yl]oxy}-14-ethyl-12,13-dihydroxy- 4-{[(2r,4s,5s,6s)-5-hydroxy-4-methoxy-4,6- Dimethyloxan-2-yl]oxy}-7-methoxy-3,5,7,9,11,13-hexamethyl-1- Oxacyclotetradecane-2,10-dione

2.4 Create Date
2005-06-24
3 Chemical and Physical Properties
Molecular Weight 748.0 g/mol
Molecular Formula C38H69NO13
XLogP33.2
Hydrogen Bond Donor Count4
Hydrogen Bond Acceptor Count14
Rotatable Bond Count8
Exact Mass747.47689126 g/mol
Monoisotopic Mass747.47689126 g/mol
Topological Polar Surface Area183 Ų
Heavy Atom Count52
Formal Charge0
Complexity1190
Isotope Atom Count0
Defined Atom Stereocenter Count18
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 NameBiaxin
PubMed HealthClarithromycin (By mouth)
Drug ClassesAntibiotic
Drug LabelClarithromycin is a semi-synthetic macrolide antibiotic. Chemically, it is 6-0-methylerythromycin. The molecular formula is C38H69NO13, and the molecular weight is 747.96. The structural formula is: Clarithromycin is a white to off-white crystalline...
Active IngredientClarithromycin
Dosage FormTreatment; Tablet; For suspension
Routemac; Oral
Strength250mg; 125mg/5ml; 500mg; 250mg/5ml
Market StatusPrescription
CompanyAbbott; Abbvie

2 of 6  
Drug NameBiaxin xl
PubMed HealthClarithromycin (By mouth)
Drug ClassesAntibiotic
Drug LabelClarithromycin is a semi-synthetic macrolide antibiotic. Chemically, it is 6-0-methylerythromycin. The molecular formula is C38H69NO13, and the molecular weight is 747.96. The structural formula is:Clarithromycin is a white to off-white crystalline p...
Active IngredientClarithromycin
Dosage FormTablet, extended release
RouteOral
Strength500mg
Market StatusPrescription
CompanyAbbvie

3 of 6  
Drug NameClarithromycin
Active IngredientClarithromycin
Dosage FormTablet, extended release; Tablet; For suspension
RouteOral
Strength250mg; 125mg/5ml; 500mg; 250mg/5ml
Market StatusPrescription
CompanyWockhardt; Ranbaxy; Teva; Actavis Labs Fl; Apotex; Aurobindo; Allied Pharma; Sandoz; Mylan; Roxane

4 of 6  
Drug NameBiaxin
PubMed HealthClarithromycin (By mouth)
Drug ClassesAntibiotic
Drug LabelClarithromycin is a semi-synthetic macrolide antibiotic. Chemically, it is 6-0-methylerythromycin. The molecular formula is C38H69NO13, and the molecular weight is 747.96. The structural formula is: Clarithromycin is a white to off-white crystalline...
Active IngredientClarithromycin
Dosage FormTreatment; Tablet; For suspension
Routemac; Oral
Strength250mg; 125mg/5ml; 500mg; 250mg/5ml
Market StatusPrescription
CompanyAbbott; Abbvie

5 of 6  
Drug NameBiaxin xl
PubMed HealthClarithromycin (By mouth)
Drug ClassesAntibiotic
Drug LabelClarithromycin is a semi-synthetic macrolide antibiotic. Chemically, it is 6-0-methylerythromycin. The molecular formula is C38H69NO13, and the molecular weight is 747.96. The structural formula is:Clarithromycin is a white to off-white crystalline p...
Active IngredientClarithromycin
Dosage FormTablet, extended release
RouteOral
Strength500mg
Market StatusPrescription
CompanyAbbvie

6 of 6  
Drug NameClarithromycin
Active IngredientClarithromycin
Dosage FormTablet, extended release; Tablet; For suspension
RouteOral
Strength250mg; 125mg/5ml; 500mg; 250mg/5ml
Market StatusPrescription
CompanyWockhardt; Ranbaxy; Teva; Actavis Labs Fl; Apotex; Aurobindo; Allied Pharma; Sandoz; Mylan; Roxane

4.2 Therapeutic Uses

Anti-Bacterial Agents

National Library of Medicine's Medical Subject Headings online file (MeSH, 2012)


Oral clarithromycin is used in combination with amoxicillin and lansoprazole or omeprazole (triple therapy) for the treatment of Helicobacter pylori infection and duodenal ulcer disease. Clarithromycin also is used orally in combination with omeprazole (dual therapy) or ranitidine bismuth citrate for the treatment of H. pylori infection in patients with an active duodenal ulcer. Clarithromycin also has been used orally in other multiple-drug regimens (with or without amoxicillin, lansoproprazole, omeprazole, or ranitidine bismuth citrate) for the treatment of H. pylori infection associated with peptic ulcer disease. /Included in US product labeling/

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 242


Clarithromycin is used orally for the treatment of pharyngitis and tonsillitis, mild to moderate respiratory tract infections (acute bacterial exacerbation of chronic bronchitis, acute maxillary sinusitis, community-acquired pneumonia), uncomplicated skin and skin structure infections, and acute otitis media caused by susceptible organisms. Clarithromycin also is used orally in the treatment of disseminated infections caused by Mycobacterium avium complex (MAC) in patients with advanced human immunodeficiency virus (HIV) infection and for prevention of disseminated MAC infection (both primary and secondary prophylaxis) in HIV-infected individuals. /Included in US product labeling/

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 242


Clarithromycin (conventional tablets) is used in conjunction with amoxicillin and lansoprazole or omeprazole (triple therapy) for the treatment of Helicobacter pylori (formerly Campylobacter pylori or C. pyloridis) infection in patients with duodenal ulcer disease (active or up to 1-year history of duodenal ulcer). Clarithromycin also is used in conjunction with omeprazole (dual therapy) or ranitidine bismuth citrate for the treatment of H. pylori infection in patients with an active duodenal ulcer. /Included in US product labeling/

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 243


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


4.3 Drug Warning

A total of 38 patients with clarithromycin-induced neurotoxicity have been reported. The average age of patients was 51.3 years (range: 19-87 years) with females comprising 52.6% of patients. Psychiatric illness was the most common comorbidity, while only two patients had renal failure. Clarithromycin had been prescribed for respiratory infections in most patients, and only two patients were receiving more than 1000 mg/day of antibiotic. The symptoms started 1 day to 10 days after starting clarithromycin (mean: 5 days). A total of 71% of patients were under treatment with concomitant medication, and eight patients were undergoing treatment with psychoactive drugs. Patients had a very good outcome after clarithromycin was discontinued, but medication with neuroleptics or benzodiazepine was required for 58% of patients in the acute phase. Only four patients underwent an electroencephalogram (EEG). Our illustrative patient was a 74-year-old woman with clarithromycin-induced delirium due to non-convulsive status epilepticus (NCSE). Her clinical symptoms and electroencephalogram (EEG) readings dramatically improved after discontinuation of clarithromycin. The mechanism underlying the central nervous system side effects remains unclear. We suggest including an EEG in the diagnostic procedures of patients under treatment with clarithromycin who develop features of neurotoxicity because an EEG can help to differentiate patients with psychiatric illness from those with encephalopathy or epilepsy. Because of the widespread use of clarithromycin, clinicians should be aware of its neurotoxicity. Early detection of clarithromycin-induced neurotoxicity and discontinuation of the drug may result in full recovery.

PMID:21269833 Bandettini di Poggio M et al; J Clin Neurosci 18 (3): 313-8 (2011)


/The investigators/ treated 13 elderly patients with chronic mycobacterial lung disease with clarithromycin using 1000 mg b.i.d. as monotherapy. Patients had a mean age of 70 years, and 12 of 13 had creatinine clearances of 31-71 ml/min. Adverse events were seen in 100% of patients, with the most common being bitter taste (92%), nausea (92%), vomiting (54%) and central nervous system symptoms (54%). Elevated liver enzymes developed in five (38%) of 13 patients at weeks 1-6 of therapy. Mean serum levels of clarithromycin plus its 14-OH metabolite were 12.9 +/- 3.6 micrograms/ml (SD). There were 11 patients (85%) who discontinued the high dose within 3 months because of side effects. Serum drug levels of clarithromycin plus its 14-OH metabolite consistently exceeded 12 micrograms/ml in six of six patients who discontinued drug (10 of 10 values) compared with neither of two patients who tolerated the high dose (0 of 6 values). A dose reduction to 500 mg b.i.d. was well tolerated (nine of 10 patients). Future trials with clarithromycin in this population should use lower doses with attention to body mass and renal function to minimize side effects.

PMID:8477575 Wallace RJ Jr et al; Diagn Microbiol Infect Dis 16 (3): 215-21 (1993)


Corneal opacities have occurred in animals at clarithromycin dosages 8- 12 times the maximum recommended human dosage (on a mg/m2 basis).

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 249


Other adverse effects reported with combined clarithromycin-omeprazole therapy that differed from those reported with omeprazole alone included rhinitis (2% of patients), pharyngitis (1% of patients), and flu syndrome (1% of patients).

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 249


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


4.4 Drug Indication

An alternative medication for the treatment of acute otitis media caused by H. influenzae, M. catarrhalis, or S. pneumoniae in patients with a history of type I penicillin hypersensitivity. Also for the treatment of pharyngitis and tonsillitis caused by susceptible Streptococcus pyogenes, as well as respiratory tract infections including acute maxillary sinusitis, acute bacterial exacerbations of chronic bronchitis, mild to moderate community-acquired pneuomia, Legionnaires' disease, and pertussis. Other indications include treatment of uncomplicated skin or skin structure infections, helicobacter pylori infection, duodenal ulcer disease, bartonella infections, early Lyme disease, and encephalitis caused by Toxoplasma gondii (in HIV infected patients in conjunction with pyrimethamine). Clarithromycin may also decrease the incidence of cryptosporidiosis, prevent the occurence of -hemolytic (viridans group) streptococcal endocarditis, as well as serve as a primary prevention for Mycobacterium avium complex (MAC) bacteremia or disseminated infections (in adults, adolescents, and children with advanced HIV infection).


FDA Label


Treatment of Helicobacter spp. infections


Treatment of Helicobacter spp. infections


5 Pharmacology and Biochemistry
5.1 Pharmacology

Clarithromycin is a macrolide antibiotic whose spectrum of activity includes many gram-positive (Staphylococcus aureus, S. pneumoniae, and S. pyogenes) and gram-negative aerobic bacteria (Haemophilus influenzae, H. parainfluenzae, and Moraxella catarrhalis), many anaerobic bacteria, some mycobacteria, and some other organisms including Mycoplasma, Ureaplasma, Chlamydia, Toxoplasma, and Borrelia. Other aerobic bacteria that clarithromycin has activity against include C. pneumoniae and M. pneumoniae. Clarithromycin has an in-vitro activity that is similar or greater than that of erythromycin against erythromycin-susceptible organisms. Clarithromycin is usually bacteriostatic, but may be bactericidal depending on the organism and the drug concentration.


5.2 MeSH Pharmacological Classification

Protein Synthesis Inhibitors

Compounds which inhibit the synthesis of proteins. They are usually ANTI-BACTERIAL AGENTS or toxins. Mechanism of the action of inhibition includes the interruption of peptide-chain elongation, the blocking the A site of ribosomes, the misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins. (See all compounds classified as Protein Synthesis Inhibitors.)


Anti-Bacterial Agents

Substances that inhibit the growth or reproduction of BACTERIA. (See all compounds classified as Anti-Bacterial Agents.)


Cytochrome P-450 CYP3A Inhibitors

Drugs and compounds which inhibit or antagonize the biosynthesis or actions of CYTOCHROME P-450 CYP3A. (See all compounds classified as Cytochrome P-450 CYP3A Inhibitors.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
CLARITHROMYCIN
5.3.2 FDA UNII
H1250JIK0A
5.3.3 Pharmacological Classes
Cytochrome P450 3A4 Inhibitors [MoA]; Macrolide Antimicrobial [EPC]; Macrolides [CS]; P-Glycoprotein Inhibitors [MoA]; Cytochrome P450 3A Inhibitors [MoA]
5.4 ATC Code

J01FA09

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


J01FA09

S66 | EAWAGTPS | Parent-Transformation Product Pairs from Eawag | DOI:10.5281/zenodo.3754448


J - Antiinfectives for systemic use

J01 - Antibacterials for systemic use

J01F - Macrolides, lincosamides and streptogramins

J01FA - Macrolides

J01FA09 - Clarithromycin


5.5 Absorption, Distribution and Excretion

Absorption

Clarithromycin is well-absorbed, acid stable and may be taken with food.


Route of Elimination

After a 250 mg tablet every 12 hours, approximately 20% of the dose is excreted in the urine as clarithromycin, while after a 500 mg tablet every 12 hours, the urinary excretion of clarithromycin is somewhat greater, approximately 30%.


Limited data are available on the distribution of clarithromycin in humans. Clarithromycin and 14-hydroxyclarithromycin appear to be distributed into most body tissues and fluids. Because of high intracellular concentrations of the drug, tissue concentrations are higher than serum concentrations. High concentrations of clarithromycin were present in tissue samples obtained from patients undergoing surgery. In patients who received 250-500 mg of clarithromycin orally every 12 hours for 3 days prior to surgery, peak clarithromycin concentrations in lung, tonsils, and nasal mucosa reportedly were attained 4 hours after administration and averaged 13.5-17.5, 5.3-6.5, and 5.9-8.3 mg/ kg, respectively; however, it has been suggested that these data may represent an overestimate of clarithromycin tissue concentrations because of the microbiologic assay's inability to distinguish between parent drug and its active metabolite. In children receiving clarithromycin suspension for otitis media at a dosage of 7.5 mg/kg every 12 hours for 5 doses, peak clarithromycin and 14- hydroxyclarithromycin concentrations in middle ear fluid were 2.5 and 1.3 ug/ mL, respectively; concomitant serum concentrations were 1.7 and 0.8 ug/mL, respectively. Results of studies in animals given radiolabeled clarithromycin or erythromycin indicate higher and more prolonged activity of clarithromycin in various body tissues, particularly the lung

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 254


Clarithromycin is absorbed rapidly from the GI tract after oral administration; GI absorption of the drug exceeds that of erythromycin.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 254


Clarithromycin is eliminated by both renal and nonrenal mechanisms.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 255


Following oral administration of a single 250-mg dose of radiolabeled clarithromycin in healthy men, approximately 38% of the dose (18% as clarithromycin) was excreted in urine, and 40% in feces (4% as clarithromycin), over 5 days. With oral administration of 250 or 500 mg of clarithromycin as tablets every 12 hours, approximately 20 or 30% of the respective dose is excreted unchanged in urine within 12 hours. After an oral clarithromycin dosage of 250 mg every 12 hours as the suspension, approximately 40% of the administered dose is excreted unchanged in urine. The principal metabolite found in urine is 14-hydroxyclarithromycin, which accounts for approximately 10-15% of the dose following administration of 250 or 500 mg of clarithromycin as tablets.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 255


For more Absorption, Distribution and Excretion (Complete) data for Clarithromycin (6 total), please visit the HSDB record page.


5.6 Metabolism/Metabolites

Hepatic - predominantly metabolized by CYP3A4 resulting in numerous drug interactions.


The principal metabolite found in urine is 14-hydroxyclarithromycin, which accounts for approximately 10-15% of the dose following administration of 250 or 500 mg of clarithromycin as tablets.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 255


Clarithromycin is extensively metabolized in the liver, principally by oxidative N- demethylation and hydroxylation at the 14 position; hydrolytic cleavage of the cladinose sugar moiety also occurs in the stomach to a minor extent. Although at least 7 metabolites of clarithromycin have been identified, 14-hydroxyclarithromycin is the principal metabolite in serum and the only one with substantial antibacterial activity. While both the R- and S-epimers of 14-hydroxyclarithromycin are formed in vivo, the R-epimer is present in greater amounts and has the greatest antimicrobial activity. Metabolism of clarithromycin appears to be saturable since the amount of 14-hydroxyclarithromycin after an 800-mg dose of the parent drug is only marginally greater than that after a 250-mg dose.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 255


Following oral administration of a single 250-mg dose of radiolabeled clarithromycin in healthy men, approximately 38% of the dose (18% as clarithromycin) was excreted in urine, and 40% in feces (4% as clarithromycin), over 5 days. ... The principal metabolite found in urine is 14-hydroxyclarithromycin, which accounts for approximately 10-15% of the dose following administration of 250 or 500 mg of clarithromycin as tablets.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 255


5.7 Biological Half-Life

3-4 hours


Following oral administration of single 250-mg or 1.2-g doses of clarithromycin conventional tablets in healthy men, the elimination half-life averaged 4 or 11 hours, respectively. During multiple dosing every 12 hours, the elimination half-life of clarithromycin reportedly increased from 3-4 hours following a 250-mg dose (conventional tablets) every 12 hours to 5-7 hours following a 500-mg dose every 8-12 hours; the half-life of 14-hydroxyclarithromycin increased from 5-6 hours with a 250-mg dose to 7-9 hours with a 500-mg dose. When clarithromycin is administered as the oral suspension, the elimination half-life of the drug and of its 14-hydroxy metabolite appear to be similar to those observed at steady-state following administration of equivalent doses of clarithromycin as tablets.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 254


5.8 Mechanism of Action

Clarithromycin is first metabolized to 14-OH clarithromycin, which is active and works synergistically with its parent compound. Like other macrolides, it then penetrates bacteria cell wall and reversibly binds to domain V of the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome, blocking translocation of aminoacyl transfer-RNA and polypeptide synthesis. Clarithromycin also inhibits the hepatic microsomal CYP3A4 isoenzyme and P-glycoprotein, an energy-dependent drug efflux pump.


Clarithromycin usually is bacteriostatic, although it may be bactericidal in high concentrations or against highly susceptible organisms. Bactericidal activity has been observed against Streptococcus pyogenes, S. pneumoniae, Haemophilus influenzae, and Chlamydia trachomatis. Clarithromycin inhibits protein synthesis in susceptible organisms by penetrating the cell wall and binding to 50S ribosomal subunits, thereby inhibiting translocation of aminoacyl transfer-RNA and inhibiting polypeptide synthesis. The site of action of clarithromycin appears to be the same as that of erythromycin, clindamycin, lincomycin, and chloramphenicol.

American Society of Health-System Pharmacists 2012; Drug Information 2012. Bethesda, MD. 2012, p. 255