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2D Structure
Also known as: 36791-04-5, Tribavirin, Rebetol, Virazole, Copegus, Ribasphere
Molecular Formula
C8H12N4O5
Molecular Weight
244.20  g/mol
InChI Key
IWUCXVSUMQZMFG-AFCXAGJDSA-N
FDA UNII
49717AWG6K

A nucleoside antimetabolite antiviral agent that blocks nucleic acid synthesis and is used against both RNA and DNA viruses.
Ribavirin is a Nucleoside Analog Antiviral.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,2,4-triazole-3-carboxamide
2.1.2 InChI
InChI=1S/C8H12N4O5/c9-6(16)7-10-2-12(11-7)8-5(15)4(14)3(1-13)17-8/h2-5,8,13-15H,1H2,(H2,9,16)/t3-,4-,5-,8-/m1/s1
2.1.3 InChI Key
IWUCXVSUMQZMFG-AFCXAGJDSA-N
2.1.4 Canonical SMILES
C1=NC(=NN1C2C(C(C(O2)CO)O)O)C(=O)N
2.1.5 Isomeric SMILES
C1=NC(=NN1[C@H]2[C@@H]([C@@H]([C@H](O2)CO)O)O)C(=O)N
2.2 Other Identifiers
2.2.1 UNII
49717AWG6K
2.3 Synonyms
2.3.1 MeSH Synonyms

1. Icn 1229

2. Icn-1229

3. Icn1229

4. Rebetol

5. Ribamide

6. Ribamidil

7. Ribamidyl

8. Ribasphere

9. Ribovirin

10. Tribavirin

11. Vilona

12. Viramide

13. Virazide

14. Virazole

2.3.2 Depositor-Supplied Synonyms

1. 36791-04-5

2. Tribavirin

3. Rebetol

4. Virazole

5. Copegus

6. Ribasphere

7. Vilona

8. Ribavirine

9. Viramid

10. Rtca

11. Cotronak

12. Ribamide

13. Ribamidil

14. Ribavirina

15. Ribavirinum

16. Ribavirine [inn-french]

17. Ribavirinum [inn-latin]

18. Icn-1229

19. Ribavirina [inn-spanish]

20. 1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamide

21. Ribavirin Mylan

22. Ribavirin Teva

23. 1-beta-d-ribofuranosyl-1h-1,2,4-triazole-3-carboxamide

24. Ribavirin Biopartners

25. Sch 18908

26. 1-((2r,3r,4s,5r)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)-1h-1,2,4-triazole-3-carboxamide

27. Rbv

28. Ribamidyl

29. Ribavirin (copegus)

30. 1-[(2r,3r,4s,5r)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,2,4-triazole-3-carboxamide

31. 1-[(2r,3r,4s,5r)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1h-1,2,4-triazole-3-carboxamide

32. Rebetron

33. Varazid

34. Nsc-163039

35. Ribavirin Capsules

36. 1h-1,2,4-triazole-3-carboxamide, 1-beta-d-ribofuranosyl-

37. Chebi:63580

38. 49717awg6k

39. Sch-18908

40. 1-(beta-d-ribofuranosyl)-1h-1,2,4-triazole-3-carboxamide

41. Rebretron

42. Virazid

43. Virazide

44. 1h-1,2,4-triazole-3-carboxamide, 1-.beta.-d-ribofuranosyl-

45. Ribav

46. Mfcd00058564

47. Dsstox_cid_3557

48. Dsstox_rid_77081

49. Dsstox_gsid_23557

50. Rtc

51. Ravanex

52. Ribacine

53. C-virin

54. Drg-0028

55. Ribasphere (tn)

56. Virazole (tn)

57. Smr000058315

58. Copegus (tn)

59. Rebetol (tn)

60. Hsdb 6513

61. Sr-01000076112

62. Brn 0892462

63. Ribavirin Teva Pharma B.v.

64. Unii-49717awg6k

65. Ribavirine;

66. Nsc163039

67. Ribavirin [usan:usp:inn:ban]

68. Ribavirin,(s)

69. Ncgc00015904-02

70. Ribavirin, Antiviral

71. Cas-36791-04-5

72. Rg-964

73. Ro-20-9963

74. Spectrum_001826

75. 4pb1

76. Ribavirin [inn]

77. Ribavirin [jan]

78. Ribavirin [mi]

79. Ribofluranosyl Carboxamide

80. Ribavirin [hsdb]

81. Ribavirin [usan]

82. Prestwick3_000993

83. Spectrum3_001876

84. Spectrum4_001252

85. Spectrum5_002075

86. Ribavirin [vandf]

87. R-964

88. Ribavirin [mart.]

89. R 9644

90. Ribavirin [usp-rs]

91. Ribavirin [who-dd]

92. Schembl3727

93. 1-.beta.-d-ribofuranosyl-1h-1,2,4-triazole-3-carboxamide

94. Chembl1643

95. Lopac0_001063

96. Bspbio_001085

97. Bspbio_003352

98. Kbiogr_001804

99. Kbioss_002331

100. Ribavirin [ema Epar]

101. Cid_37542

102. Mls000028486

103. Mls002222317

104. Divk1c_000782

105. Spectrum1503938

106. Ribavirin (jp17/usp/inn)

107. Bpbio1_001195

108. Gtpl6842

109. Ribavirin [orange Book]

110. 1,2,4-triazole-3-carboxamide, 1-beta-d-ribofuranosyl-

111. 1-(beta-d-ribofuranosyl)-1,2,4-triazole-3-carboxamide

112. 1-.beta.-d-ribofuranosyl-1,2,4-triazolo-3-carboxamide

113. Dtxsid8023557

114. Ribavirin [ep Monograph]

115. Hms502h04

116. Kbio1_000782

117. Kbio2_002328

118. Kbio2_004896

119. Kbio2_007464

120. Kbio3_002854

121. Ribavirin [usp Monograph]

122. Ninds_000782

123. Hms2090l15

124. Hms2094o09

125. Hms2098g07

126. Hms2232p07

127. Hms3263e08

128. Hms3715g07

129. Pharmakon1600-01503938

130. 66510-90-5

131. Hy-b0434

132. Zinc1035331

133. Tox21_110259

134. Tox21_200967

135. Tox21_501063

136. Bdbm50154375

137. Ccg-38985

138. Nsc758650

139. S2504

140. Ribavirin 100 Microg/ml In Methanol

141. Akos001715163

142. Tox21_110259_1

143. Db00811

144. Gs-3572

145. Lp01063

146. Nsc-758650

147. Sdccgsbi-0051033.p004

148. Idi1_000782

149. Smp1_000261

150. Ncgc00090726-01

151. Ncgc00090726-03

152. Ncgc00090726-04

153. Ncgc00090726-05

154. Ncgc00090726-06

155. Ncgc00090726-07

156. Ncgc00090726-08

157. Ncgc00090726-09

158. Ncgc00090726-12

159. Ncgc00090726-25

160. Ncgc00090726-30

161. Ncgc00258520-01

162. Ncgc00261748-01

163. 252269-50-4

164. As-34178

165. Bcp0726000138

166. Ribavirin Component Of Peginterferon

167. Sbi-0051033.p003

168. Ab00430481

169. Eu-0101063

170. R0077

171. En300-59237

172. D00423

173. Ab00430481-15

174. Ab00430481-16

175. Ab00430481_17

176. Ab00430481_18

177. 1-beta-ribofuranosyl-1,2,4-triazole-3-carboamide

178. 791r045

179. A823370

180. Q421862

181. Ribavirin 100 Microg/ml In Acetonitrile:methanol

182. Sr-01000721904

183. 1-b-d-ribofuranosyl-1,2,4-triazole-3-carboxamide

184. 1-ss-d-ribofuranosyl-1,2,4-triazole-3-carboxamide

185. Sr-01000076112-2

186. Sr-01000076112-3

187. Sr-01000076112-4

188. Sr-01000721904-2

189. Brd-k60369935-001-02-7

190. Brd-k60369935-001-18-3

191. Sr-01000076112-11

192. 1-?-d-ribofuranosyl-1h-1,2,4-triazole-3-carboxamide

193. Ribavirin, British Pharmacopoeia (bp) Reference Standard

194. Z1522567185

195. 1-(beta -d-ribofuranosyl)-1,2,4-triazole-3-carboxamide

196. Ribavirin, European Pharmacopoeia (ep) Reference Standard

197. Ribavirin, United States Pharmacopeia (usp) Reference Standard

198. Ribavirin, Pharmaceutical Secondary Standard; Certified Reference Material

199. 1-[(2r,3r,4s,5r)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl]-1,2,4-triazole-3-carboxamide

200. 1-[(2r,3s,5r)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl]-1,2,4-triazole-3-carboxamide

2.4 Create Date
2005-06-24
3 Chemical and Physical Properties
Molecular Weight 244.20 g/mol
Molecular Formula C8H12N4O5
XLogP3-1.8
Hydrogen Bond Donor Count4
Hydrogen Bond Acceptor Count7
Rotatable Bond Count3
Exact Mass244.08076950 g/mol
Monoisotopic Mass244.08076950 g/mol
Topological Polar Surface Area144 Ų
Heavy Atom Count17
Formal Charge0
Complexity304
Isotope Atom Count0
Defined Atom Stereocenter Count4
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 10  
Drug NameCopegus
PubMed HealthRibavirin
Drug ClassesAntiviral
Drug LabelCOPEGUS, ribavirin, is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1--D-ribofuranosyl-1H-1,2,4-triazole-3-carboxamide and has the following structural formula:The empirical formula of ribavirin is C8H12N4O5 and...
Active IngredientRibavirin
Dosage FormTablet
RouteOral
Strength200mg
Market StatusPrescription
CompanyRoche

2 of 10  
Drug NameRebetol
PubMed HealthRibavirin
Drug ClassesAntiviral
Drug LabelREBETOL (ribavirin), is a synthetic nucleoside analogue (purine analogue). The chemical name of ribavirin is 1--D-ribofuranosyl-1H-1,2,4-triazole-3-carboxamide and has the following structural formula (see Figure 1).Figure 1: Structural FormulaRiba...
Active IngredientRibavirin
Dosage FormCapsule; Solution
RouteOral
Strength200mg; 40mg/ml; 200mg **indicated for use and comarketed with interferon alfa-2b, recombinant (intron a), as rebetron combination therapy**
Market StatusPrescription
CompanyMerck Sharp Dohme; Schering

3 of 10  
Drug NameRibasphere
PubMed HealthRibavirin
Drug ClassesAntiviral
Drug LabelRIBASPHERE (ribavirin, USP), is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1-and has the following structural formula:The molecular formula of ribavirin is C8H12N4O5 and the molecular weight is 244.2. Ribavirin i...
Active IngredientRibavirin
Dosage FormCapsule
RouteOral
Strength200mg
Market StatusPrescription
CompanyThree Rivers Pharms

4 of 10  
Drug NameRibavirin
Drug LabelRIBASPHERE (ribavirin, USP), is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1-and has the following structural formula:The molecular formula of ribavirin is C8H12N4O5 and the molecular weight is 244.2. Ribavirin i...
Active IngredientRibavirin
Dosage FormTablet; Capsule; Solution
Routeoral; Oral
Strength200mg; 600mg; 500mg; 400mg; 40mg/ml
Market StatusTentative Approval; Prescription
CompanyTeva; Aurobindo Pharma; Sandoz; Teva Pharms; Zydus Pharms Usa; Three Rivers Pharms

5 of 10  
Drug NameVirazole
Drug LabelVIRAZOLE is a brand name for ribavirin, a synthetic nucleoside with antiviral activity. VIRAZOLE for inhalation solution is a sterile, lyophilized powder to be reconstituted for aerosol administration. Each 100 mL glass vial contains 6 grams of rib...
Active IngredientRibavirin
Dosage FormFor solution
RouteInhalation
Strength6gm/vial
Market StatusPrescription
CompanyValeant Pharm Intl

6 of 10  
Drug NameCopegus
PubMed HealthRibavirin
Drug ClassesAntiviral
Drug LabelCOPEGUS, ribavirin, is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1--D-ribofuranosyl-1H-1,2,4-triazole-3-carboxamide and has the following structural formula:The empirical formula of ribavirin is C8H12N4O5 and...
Active IngredientRibavirin
Dosage FormTablet
RouteOral
Strength200mg
Market StatusPrescription
CompanyRoche

7 of 10  
Drug NameRebetol
PubMed HealthRibavirin
Drug ClassesAntiviral
Drug LabelREBETOL (ribavirin), is a synthetic nucleoside analogue (purine analogue). The chemical name of ribavirin is 1--D-ribofuranosyl-1H-1,2,4-triazole-3-carboxamide and has the following structural formula (see Figure 1).Figure 1: Structural FormulaRiba...
Active IngredientRibavirin
Dosage FormCapsule; Solution
RouteOral
Strength200mg; 40mg/ml; 200mg **indicated for use and comarketed with interferon alfa-2b, recombinant (intron a), as rebetron combination therapy**
Market StatusPrescription
CompanyMerck Sharp Dohme; Schering

8 of 10  
Drug NameRibasphere
PubMed HealthRibavirin
Drug ClassesAntiviral
Drug LabelRIBASPHERE (ribavirin, USP), is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1-and has the following structural formula:The molecular formula of ribavirin is C8H12N4O5 and the molecular weight is 244.2. Ribavirin i...
Active IngredientRibavirin
Dosage FormCapsule
RouteOral
Strength200mg
Market StatusPrescription
CompanyThree Rivers Pharms

9 of 10  
Drug NameRibavirin
Drug LabelRIBASPHERE (ribavirin, USP), is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1-and has the following structural formula:The molecular formula of ribavirin is C8H12N4O5 and the molecular weight is 244.2. Ribavirin i...
Active IngredientRibavirin
Dosage FormTablet; Capsule; Solution
Routeoral; Oral
Strength200mg; 600mg; 500mg; 400mg; 40mg/ml
Market StatusTentative Approval; Prescription
CompanyTeva; Aurobindo Pharma; Sandoz; Teva Pharms; Zydus Pharms Usa; Three Rivers Pharms

10 of 10  
Drug NameVirazole
Drug LabelVIRAZOLE is a brand name for ribavirin, a synthetic nucleoside with antiviral activity. VIRAZOLE for inhalation solution is a sterile, lyophilized powder to be reconstituted for aerosol administration. Each 100 mL glass vial contains 6 grams of rib...
Active IngredientRibavirin
Dosage FormFor solution
RouteInhalation
Strength6gm/vial
Market StatusPrescription
CompanyValeant Pharm Intl

4.2 Therapeutic Uses

Antimetabolites; Antiviral Agents

National Library of Medicine, SIS; ChemIDplus Record for Ribavirin (36791-04-5), MESH Heading. Available from, as of March 15, 2006: https://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp


Antiviral

O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. 13th Edition, Whitehouse Station, NJ: Merck and Co., Inc., 2001., p. 1470


Oral and intravenous ribavirin are used in the treatment of Lassa fever and as post-exposure prophylaxis in contacts at hgh risk. It may be similarly effective with other viral hemorrhagic fevers, including hemorrhagic fever with renal syndrome, Crimean-Congo hemorrhagic fever, and Rift Valley fever. /NOT included in US product labeling/

Thomson/Micromedex. Drug Information for the Health Care Professional. Volume 1, Greenwood Village, CO. 2006., p. 2584


Ribavirin inhalation solution is used as a secondary agent in the treatment of influenza A and B in young adults when treatment is started early (eg, within 24 hours of initial symptoms) in the course of the disease. /NOT included in US product labeling/

Thomson/Micromedex. Drug Information for the Health Care Professional. Volume 1, Greenwood Village, CO. 2006., p. 2584


Ribavirin inhalation solution is for the treatment of severe lower respiratory tract infections (including bronchiolitis and pneumonia) caused by respiratory syncytial virus (RSV) in hospitalized infants and young children who are at high risk for severe or complicated RSV infection; this category includes premature infants and infants with structural or physiologic cardiopulmonary disorder, bronchopulmonary dysplasia, immunodeficiency, or imminent respiratory failure. Ribavirin is indicated in the treatment of RSV infections in infants requiring mechanical ventilator assistance. /Included in US product labeling/

Thomson/Micromedex. Drug Information for the Health Care Professional. Volume 1, Greenwood Village, CO. 2006., p. 2584


4.3 Drug Warning

FDA Pregnancy Risk Category: X /CONTRAINDICATED IN PREGNANCY. Studies in animals or humans, or investigational or post-marketing reports, have demonstrated positive evidence of fetal abnormalities or risk which clearly outweights any possible benefit to the patient./

Thomson/Micromedex. Drug Information for the Health Care Professional. Volume 1, Greenwood Village, CO. 2006., p. 2585


Evidence of disease progression, such as hepatic inflammation and fibrosis, as well as prognostic factors for response. HCV genotype and viral load, should be considered when deciding to treat a pediatric patient. The benefits of treatment should be weighed against the safety findings observed for pediatric patients in clinical trials.

Thomson/Micromedex. Drug Information for the Health Care Professional. Volume 1, Greenwood Village, CO. 2006., p. 2585


Worsening of respiratory function has occurred, sometimes suddenly, during ribavirin inhalation therapy in infants with RSV infections or in adults with chronic obstructive pulmonary disease (COPD) or asthma. In infants with underlying life-threatening conditions, inhalation of the drug has been associated with aggravation and worsening of respiratory function, apnea, and physical dependence on assisted respiration. In adults with COPD or asthma, therapy with the drug frequently has been associated with deterioration in pulmonary function, and dyspnea and chest soreness have occurred in several adults with asthma. Minor pulmonary function abnormalities have also been observed in healthy adults receiving ribavirin inhalation. Bronchospasm, pulmonary edema, hypoventilation, cyanosis, dyspnea, bacterial pneumonia, pneumothorax, apnea, atelectasis, and ventilator dependence also have been associated with ribavirin inhalation therapy. Several deaths that were characterized as possibly related to ribavirin inhalation therapy by the treating physician occurred in infants who experienced worsening respiratory status related to bronchospasm while receiving the drug.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 805


Rash, erythema of the eyelids, and conjunctivitis have occurred in patients receiving ribavirin inhalation therapy. These effects usually resolve within hours after ribavirin therapy is discontinued. In addition, hearing disorders (e.g., hearing loss, tinnitus), vertigo, hypertriglyceridemia, and fatal and nonfatal pancreatitis have been observed in patients receiving ribavirin in conjunction with interferon alfa-2b.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 806


For more Drug Warnings (Complete) data for RIBAVIRIN (23 total), please visit the HSDB record page.


4.4 Drug Indication

Indicated for the treatment of chronic Hepatitis C virus (HCV) infection in combination with other antiviral agents with the intent to cure or achieve a sustained virologic response (SVR). Typically added to improve SVR and reduce relapse rates. The addition of ribavirin in Technivie therapy indicated for treating HCV genotype 1a and 4 infections is recommended in patients with or without cirrhosis. Resistance: viral genetic determinants resulting in variable response to ribavirin therapy has not been yet determined.


FDA Label


Rebetol is indicated in combination with other medicinal products for the treatment of chronic hepatitis C (CHC) in adults.

Rebetol is indicated in combination with other medicinal products for the treatment of chronic hepatitis C (CHC) for paediatric patients (children 3 years of age and older and adolescents) not previously treated and without liver decompensation.


Ribavirin Mylan is indicated for the treatment of chronic hepatitis C and must only be used as part of a combination regimen with interferon alfa-2b (adults, children (three years of age and older) and adolescents). Ribavirin monotherapy must not be used.

There is no safety or efficacy information on the use of ribavirin with other forms of interferon (i. e. not alfa-2b).

Please refer also to the interferon alfa-2b summary of product characteristics (SmPC) for prescribing information particular to that product.

* Nave patients:

Adult patients

Ribavirin Mylan is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, with elevated alanine aminotransferase (ALT), who are positive for serum hepatitis-C-virus (HCV) RNA.

Children and adolescents

Ribavirin Mylan is indicated, in a combination regimen with interferon alfa-2b, for the treatment of children and adolescents three years of age and older, who have all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, and who are positive for serum HCV RNA. When deciding to not to defer treatment until adulthood, it is important to consider that the combination therapy induced a growth inhibition. The reversibility of growth inhibition is uncertain. The decision to treat should be made on a case-by-case basis (see section 4. 4).

* Previously treatment-failure patients:

Adult patients

Ribavirin Mylan is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with chronic hepatitis C who have previously responded (with normalisation of ALT at the end of treatment) to interferon alpha monotherapy but who have subsequently relapsed.


Ribavirin Teva Pharma B. V. is indicated in combination with other medicinal products for the treatment of

chronic hepatitis C (CHC) in adults (see sections 4. 2, 4. 4, and 5. 1).

Ribavirin Teva Pharma B. V. is indicated in combination with other medicinal products for the treatment of

chronic hepatitis C (CHC) for paediatric patients (children 3 years of age and older and adolescents) not

previously treated and without liver decompensation (see sections 4. 2, 4. 4 and 5. 1).


Ribavirin Teva is indicated for the treatment of chronic hepatitis C virus (HCV) infection in adults, children 3 years of age and older and adolescents and must only be used as part of a combination regimen with interferon alfa-2b. Ribavirin monotherapy must not be used.

There is no safety or efficacy information on the use of Ribavirin with other forms of interferon (i. e. not alfa-2b).

* Nave patients:

*:

Adult patients

Ribavirin Teva is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, with elevated alanine aminotransferase (ALT), who are positive for hepatitis C viral ribonucleic acid HCV-RNA.

Paediatric patients (children 3 years of age and older and adolescents)

Ribavirin Teva is indicated, in a combination regimen with interferon alfa2b, for the treatment of children and adolescents 3 years of age and older, who have all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, and who are positive for HCV-RNA.

When deciding not to defer treatment until adulthood, it is important to consider that the combination therapy induced a growth inhibition that may be irreversible in some patients. The reversibility of growth inhibition is uncertain. The decision to treat should be made on a case by case basis.

* Previous treatment failure patients:

Adult patients

Ribavirin Teva is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with chronic hepatitis C who have previously responded (with normalisation of ALT at the end of treatment) to interferon alpha monotherapy but who have subsequently relapsed.


Ribavirin BioPartners is indicated for the treatment of chronic hepatitis-C-virus (HCV) infection in adults, children three years of age and older and adolescents and must only be used as part of a combination regimen with interferon alfa-2b. Ribavirin monotherapy must not be used. There is no safety or efficacy information on the use of ribavirin with other forms of interferon (i. e. not alfa-2b).

* Nave patients:

Adult patients

Ribavirin BioPartners is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, with elevated alanine aminotransferase (ALT), who are positive for hepatitis C viral ribonucleic acid (HCV-RNA) (see section 4. 4)

Children three years of age and older and adolescents

Ribavirin BioPartners is intended for use, in a combination regimen with interferon alfa-2b, for the treatment of children three years of age and older and adolescents, who have all types of chronic hepatitis C except genotype 1, not previously treated, without liver decompensation, and who are positive for HCV-RNA.

When deciding to not to defer treatment until adulthood, it is important to consider that the combination therapy induced a growth inhibition. The reversibility of growth inhibition is uncertain. The decision to treat should be made on a case by case basis (see section 4. 4).

* Previous-treatment-failure patients:

Adult patients

Ribavirin BioPartners is indicated, in combination with interferon alfa-2b, for the treatment of adult patients with chronic hepatitis C who have previously responded (with normalisation of ALT at the end of treatment) to interferon alfa monotherapy but who have subsequently relapsed (see section 5. 1).


Cotronak is indicated for the treatment of chronic hepatitis C and must only be used as part of a combination regimen with peginterferon alfa-2b or interferon alfa-2b. Cotronak monotherapy must not be used.

There is no safety or efficacy information on the use of Cotronak with other forms of interferon (i. e. , not alfa-2b).

Please refer also to the peginterferon alfa-2b or interferon alfa-2b Summary of Product Characteristics (SPC) for prescribing information particular to that product.


Treatment of chronic viral hepatitis C


5 Pharmacology and Biochemistry
5.1 Pharmacology

Ribavirin mediates direct antiviral activity against a number of DNA and RNA viruses by increasing the mutation frequency in the genomes of several RNA viruses. It is a member of the nucleoside antimetabolite drugs that interfere with duplication of the viral genetic material. The drug inhibits the activity of the enzyme RNA dependent RNA polymerase, due to its resemblence to building blocks of the RNA molecules.


5.2 MeSH Pharmacological Classification

Antimetabolites

Drugs that are chemically similar to naturally occurring metabolites, but differ enough to interfere with normal metabolic pathways. (From AMA Drug Evaluations Annual, 1994, p2033) (See all compounds classified as Antimetabolites.)


Antiviral Agents

Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly. (See all compounds classified as Antiviral Agents.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
RIBAVIRIN
5.3.2 FDA UNII
49717AWG6K
5.3.3 Pharmacological Classes
Nucleoside Analog [EXT]; Nucleoside Analog Antiviral [EPC]
5.4 ATC Code

J05AP01


J05AB04


J05AP01


J05AB04


J05AB04


J05AB04


J05AP01

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

J05 - Antivirals for systemic use

J05A - Direct acting antivirals

J05AP - Antivirals for treatment of hcv infections

J05AP01 - Ribavirin


5.5 Absorption, Distribution and Excretion

Absorption

Ribavirin is reported to be rapidly and extensively absorbed following oral administration. The average time to reach Cmax was 2 hours after oral administration of 1200 mg ribavirin. The oral bioavailability is 64% following a single oral dose administration of 600mg ribavirin.


Route of Elimination

The metabolites of ribavirin are renally excreted. After the oral administration of 600mg radiolabeled ribavirin, approximately 61% of the drug was detected in the urine and 12% was detected in the feces. 17% of administered dose was in unchanged form.


Volume of Distribution

Ribavirin displays a large volume of distribution.


Clearance

The total apparent clearance rate after a single oral dose administration of 1200 mg ribavirin is 26L/h.


Ribavirin is absorbed systemically from the respiratory tract following nasal and oral inhalation. The bioavailability of ribavirin administered via nasal and oral inhalation has not been determined but may depend on the method of drug delivery during nebulization (eg, oxygen hood, face mask, oxygen tent). At a constant flow rate, the amount of drug delivered to the respiratory tract theoretically is directly related to the concentration of nebulized drug solution and the duration of inhalation therapy. In addition, alterations in the method of aerosol delivery can affect the amount of drug reaching the respiratory tract. The fraction of an inhaled dose of ribavirin that is deposited in the respiratory tract during oral and nasal inhalation of a nebulized solution containing 190 ug/L using a small particle aerosol generator has been estimated to average about 70%, but the actual amount deposited depends on several factors including respiratory rate and tidal volume.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 810


Peak plasma ribavirin concentrations generally appear to occur at the end of the inhalation period when the drug is inhaled orally and nasally using a small particle aerosol generator, and increase with increasing duration of the inhalation period. Following nasal and oral inhalation (via face mask) of 0.82 mg/kg/hr for 2.5 hr daily for 3 days in a limited number of pediatric patients, peak plasma ribavirin concentrations averaged 0.19 (range: 0.11-0.388) ug/mL. Peak plasma ribavirin concentrations averaged 0.275 (range: 0.21-0.35) or 1.1 (range: 0.45-2.18) ug/mL in a limited number of patients inhaling 0.82 mg/kg per hour for 5 or 8 hr daily, respectively, for 3 days, and averaged 1.7 (range: 0.38-3.58) ug/mL in a limited number of pediatric patients inhaling 0.82 mg/kg per hour via face mask, mist tent, or respirator for 20 hr daily for 5 days. Highest plasma concentrations for a given dosage of ribavirin appear to be achieved in patients receiving the drug from the aerosol generator via an endotracheal tube. ... Peak plasma ribavirin concentrations achieved with nasal and oral inhalation of usual dosages of the drug are less than concentrations that reportedly reduce respiratory syncytial virus plaque formation by 85-98%.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 810


Concentrations of ribavirin achieved in respiratory tract secretions in patients inhaling the drug nasally and orally are likely to be substantially greater than those achieved in plasma. In a limited number of pediatric patients who received a nasally and orally inhaled ribavirin dose of 0.82 mg/kg per hour for 8 hr daily for 3 days, peak concentrations of the drug in respiratory tract secretions (from endotracheal tube) ranged from 250-1925 ug/mL. In pediatric patients who received 0.82 mg/kg per hour via nasal and oral inhalation for 20 hr daily for 5 days, ribavirin concentrations in respiratory tract secretions (from endotracheal tube) ranged from 313-28,250 ug/mL during therapy, with peak concentrations averaging 3075 (range: 313-7050) ug/mL at the end of therapy. Concentrations of ribavirin achieved in respiratory tract secretions via nasal and oral inhalation are likely to be substantially greater than concentrations necessary to inhibit plaque formation of susceptible strains of respiratory syncytial virus in vitro; however, because respiratory syncytial virus is found within virus infected cells in the respiratory tract, the manufacturer states that intracellular respiratory tract drug concentrations may be more closely related to plasma ribavirin concentrations than to those measured in respiratory tract secretions.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 810


Ribavirin is rapidly absorbed following oral administration, with peak plasma concentrations of the drug occurring within 1-3 hr after multiple doses. However, the absolute bioavailability of ribavirin averages only 64% following oral administration because the drug undergoes first-pass metabolism.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 810


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


5.6 Metabolism/Metabolites

First and as a step required for activation, ribavirin is phosphorylated intracellularly by adenosine kinase to ribavirin mono-, di-, and triphosphate metabolites. After activation and function, ribavirin undergoes two metabolic pathways where it is reversibly phosphorlyated or degraded via deribosylation and amide hydrolysis to yield a triazole carboxylic acid metabolite. In vitro studies indicate that ribavirin is not a substrate of CYP450 enzymes.


Ribavirin is metabolized principally to deribosylated ribavirin (the 1,2,4-triazole-3-carboxamide), probably in the liver; the antiviral activity of 1,2,4-triazole-3-carboxamide against various RNA and DNA viruses is reportedly similar to ribavirin. The drug is also metabolized to 1,2,4-triazole-3-carboxylic acid. In vitro, ribavirin has been shown to be metabolized to ribavirin-5'-monophosphate, -diphosphate, and -triphosphate, principally by intracellular phosphorylation of the drug via adenosine kinase and other cellular enzymes. It is likely that phosphorylation in vivo is necessary for the antiviral activity of the drug. Ribavirin also undergoes phosphorylation in erythrocytes, principally to ribavirin-5'-triphosphate; approximately 81, 16, and 3% of drug metabolized in erythrocytes is present as ribavirin-5'-triphosphate, -diphosphate, and -monophosphate, respectively. It has been suggested that prolonged distribution of the drug in erythrocytes may result from minimal phosphatase activity in these cells with transit of the drug out of cells dependent on dephosphorylation via phosphatases.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 811


Ribavirin has two pathways of metabolism: (i) a reversible phosphorylation pathway in nucleated cells; and (ii) a degradative pathway involving deribosylation and amide hydrolysis to yield a triazole carboxylic acid metabolite. Ribavirin and its triazole carboxamide and triazole carboxylic acid metabolites are excreted renally.

Physicians Desk Reference 60th ed, Thomson PDR, Montvale, NJ 2006., p. 3083


5.7 Biological Half-Life

The terminal half-life of ribavirin following administration of a single oral dose of 1200 mg is about 120 to 170 hours.


Distribution: Intravenous: Approximately 0.2 hours. Elimination: inhalation: 9.5 hours. Intravenous and oral (single dose): 0.5 to 2 hours. In erythrocytes: 40 days. Terminal: Intravenous and oral: Single dose: 27 to 36 hours. Single oral dose tablet: 120 to 170 hours. Steady state: Approximately 151 hours. Mean :multiple oral dosing, capsule: 298 hours.

Thomson/Micromedex. Drug Information for the Health Care Professional. Volume 1, Greenwood Village, CO. 2006., p. 2585


Based on limited data, the half-life of ribavirin in respiratory tract secretions following nasal and oral inhalation for 3 days reportedly is approximately 1.4-2.5 hr.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 811


Following nasal and oral inhalation in a limited number of pediatric patients, the plasma half-life of ribavirin averaged about 9.5 (range: 6.5-11) hr. Following oral administration of a single dose of the drug in a limited number of healthy adults, plasma ribavirin concentrations declined in a multiphasic manner, with half-lives averaging 24 hr 10-80 hr after the dose and 48 hr or longer in the terminal phase.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 811


5.8 Mechanism of Action

Ribavirin is reported to have several mechanism of actions that lead to inhibition of viral RNA and protein synthesis. After activation by adenosine kinase to ribavirin mono-, di-, and triphosphate metabolites. Ribavirin triphosphate (RTP) is the predominant metabolite which directly inhibits viral mRNA polymerase by binding to the nucleotide binding site of the enzyme. This prevents the binding of the correct nucleotides, leading to a reduction in viral replication or to the production of defective virions. RTP also demonstrates an inhibitory action on viral mRNA guanylyltransferase and mRNA 2-O-methyltransferase of dengue virus. Inhibition of these enzymes disrupts the posttranslational capping of the 5 end of viral mRNA through ribavirin being incorporated at the 5 end in place of guanosine and preventing the cap methylation step. Inhibition of host inosine monophosphate dehydrogenase (IMPDH) and subsequent depletion of GTP pool is proposed to be another mechanism of action of ribavirin. IMPDH catalyzes the rate-limiting step where inosine 5-monophosphate is converted to xanthine monophosphate during guanosine monophosphate (GMP) synthesis. GMP is later converted to guanosine triphoshpate (GTP). Ribavirin monophosphate mimics inosine 5-monophosphate and acts as a competitive inhibitor of IMPDH. Inhibited de novo synthesis of guanine nucleotides and decreased intracellular GTP pools leads to a decline in viral protein synthesis and limit replication of viral genomes. Ribavirin acts as a mutagen in the target virus to cause an 'error catastrophe' due to increased viral mutations. RTP pairs with cytidine triphosphate or uridine triphosphate with equal efficiency and to block HCV RNA elongation. It causes premature termination of nascent HCV RNA and increases mutagenesis by producing defective virions. Ribavirin also exerts an immunomodulatory action of the host to the virus by shifting a Th2 response in favor of a Th1 phenotype. Th2 response and production of type 2 cytokines such as IL-4, IL-5, and IL-10 stimulates the humoral response which enhances immunity toward the virus. Ribavirin enhanced induction of interferon-related genes, including the interferon- receptor, and down-regulation of genes involved in interferon inhibition, apoptosis, and hepatic stellate cell activation in vitro.


The exact mechanism of action of the antiviral activity of ribavirin has not been fully elucidated, but the drug appears to exert its antiviral activity by interfering with RNA and DNA synthesis and subsequently inhibiting protein synthesis and viral replication. The antiviral activity of the drug results principally in an intracellular virustatic effect in cells infected with ribavirin sensitive RNA or DNA viruses; however, specific mechanisms of action of the drug may vary depending on the virus. In virus infected cells in vitro, ribavirin generally exhibits a greater affinity for inhibition of viral DNA and RNA synthesis than cellular (host cell) DNA and RNA synthesis. However, in vesicular stomatitis virus infected cells in vitro, the drug appeared to exhibit a greater affinity for inhibition of cellular than viral RNA synthesis. Inhibition of cellular RNA synthesis usually occurs only at in vitro concentrations higher than those necessary for inhibition of cellular DNA synthesis.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 809


The antiviral activity of ribavirin appears to depend principally on intracellular conversion of the drug to ribavirin-5'-triphosphate and -monophosphate. Ribavirin-5'-diphosphate exhibits minimal antiviral activity compared with the monophosphate or triphosphate. Ribavirin is readily absorbed across the cellular plasma membrane, probably via a nucleoside transport mechanism. The drug is then converted via cellular enzymes to deribosylated ribavirin (the 1,2,4-triazole-3-carboxamide) and phosphorylated to ribavirin-5'-monophosphate, -diphosphate, and -triphosphate. Phosphorylation of ribavirin occurs principally in virus infected cells, but also occurs in uninfected cells. Ribavirin is converted to ribavirin-5'-monophosphate via adenosine kinase; the monophosphate is phosphorylated to the diphosphate and triphosphate via other cellular enzymes, including adenosine kinase. The enzyme deoxyadenosine kinase may also participate in the phosphorylation of ribavirin. Formation of ribavirin-5'-monophosphate appears to be the rate limiting step in the formation of ribavirin-5'-triphosphate. The extent of phosphorylation of ribavirin by both uninfected and virus-infected cells in vitro is directly related to the extracellular (eg, in the culture medium) concentration of the drug. Ribavirin-5'-triphosphate is the principal intracellular form of the drug,with only approximately 4 and 12% of the phosphorylated metabolites present as ribavirin-5'-diphosphate and -monophosphate, respectively. Transit of the drug out of cells appears to occur only after dephosphorylation via phosphatases.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 809


In vitro studies with influenza virus indicate that ribavirin-5'-triphosphate functions as a preferential inhibitor of viral RNA polymerase. Ribavirin-5'-triphosphate competes with adenosine-5'-triphosphate and guanosine-5'-triphosphate for viral RNA polymerase. Inhibition of cellular (host cell) RNA polymerase reportedly is minimal and reversible. In vitro studies with influenza virus have shown that ribavirin-5'-triphosphate also inhibits viral replication by inhibiting guanylyltransferase and methyltransferase, enzymes necessary for the addition of guanosine triphosphate to the 5' terminus ("cap") of viral messenger RNA (mRNA), and by competing with guanosine for incorporation into the 5' terminus of viral mRNA. Although the rate of synthesis of mRNA does not appear to be affected, the efficiency of translation of mRNA inviral replication is decreased by about 80%. Viruses in which the 5' mRNA terminus is naturally absent (eg, poliovirus) are generally not substantially inhibited by ribavirin.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 809


In vitro studies indicate that ribavirin inhibits phosphorylation of thymidine at drug concentrations of 2 umol/L (0.5 ug/mL) and that DNA synthesis is inhibited only at drug concentrations of 200 umol/L (50 ug/mL). Unlike acyclovir, ribavirin appears to be incorporated minimally, if at all, into growing chains of DNA and RNA. In vitro studies with vaccinia virus have shown that the virus DNA fails to coat in the presence of ribavirin, resulting in incomplete viral particles.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 809


At lower dosages, stimulation of antibody formation against some viruses has been reported. The drug has been shown to stimulate T cells (T-lymphocytes) indirectly by inhibiting splenic suppressor cells and to produce a dose dependent inhibition of antigen and mitogen induced proliferation of lymphocytes without affecting cell survival. In human infants, antibody formation against respiratory syncytial virus has decreased during therapy with ribavirin, but the clinical importance of this finding is not known. The drug has been shown to have little, if any, effect on antibody formation against influenza A or B or measles virus in infected patients. Decreases in antibody formation during viral infections may result from decreases in antigenic stimulation secondary to ribavirin-induced inhibition of viral replication or from a direct inhibition of antibody formation by the drug. Ribavirin may indirectly inhibit respiratory syncytial virus specific immunoglobulin E and histamine, which are increased in infants who have wheezing in association with respiratory syncytial virus infection, by decreasing respiratory syncytial virus and attendant antigenic stimulation.

McEvoy, G.K. (ed.). American Hospital Formulary Service- Drug Information 2005. Bethesda, MD: American Society of Health-System Pharmacists, Inc. 2005 (Plus Supplements)., p. 809