Ribavirin

Athanor · official

C₈H₁₂N₄O₅ · 244.2 g/mol

IUPAC name: 1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,2,4-triazole-3-carboxamide

Also called Rebetol, Copegus, hepatitis C

Drugs Rings

Open in Athanor

Drawn from its SMILES with RDKit

DangerMay cause an allergic skin reaction · Causes serious eye irritation · May cause respiratory irritation · Suspected of causing genetic defects · May damage fertility or the unborn child · Suspected of damaging fertility or the unborn child · May causes damage to organs through prolonged or repeated exposure · Harmful to aquatic life with long lasting effects

Names and identifiers

IUPAC name: 1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,2,4-triazole-3-carboxamide
Synonyms: Rebetol, Copegus, hepatitis C
+ 36 more
Tribavirin, Virazole, Ribamidil, Ribavirine, Vilona, Viramid, Ribasphere, RTCA, Ribavirina, Varazid, Ribavirinum, Cotronak, ICN-1229, 1-beta-D-Ribofuranosyl-1H-1,2,4-triazole-3-carboxamide, Virazid, Ribavirin Mylan, Ribavirin Teva, 1-beta-D-Ribofuranosyl-1,2,4-triazole-3-carboxamide, Ribavirin BioPartners, SCH 18908, DTXSID8023557, 1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1,2,4-triazole-3-carboxamide, Ribavirin Teva Pharma B.V., NSC-163039, 1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1H-1,2,4-triazole-3-carboxamide, CHEBI:63580, 49717AWG6K, ribofluranosyl carboxamide, 1H-1,2,4-Triazole-3-carboxamide, 1-beta-D-ribofuranosyl-, SCH-18908, DTXCID603557, Ribovirin, Viramide, NSC 163039, NSC163039, Ribavarin
Molecular formula: C₈H₁₂N₄O₅
Empirical formula: C₈H₁₂N₄O₅
Molecular weight: 244.2 g/mol
Exact mass: 244.08077
CAS number: 36791-04-5
PubChem CID: 37542
Canonical SMILES: C1=NC(=NN1C2C(C(C(O2)CO)O)O)C(=O)N
Isomeric SMILES: C1=NC(=NN1[C@H]2[C@@H]([C@@H]([C@H](O2)CO)O)O)C(=O)N
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
InChIKey: IWUCXVSUMQZMFG-AFCXAGJDSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: White crystalline powder[2]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Ribavirin is a white powder. Exists in two polymorphic forms. (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–shown White crystalline powder [2] Hazardous Substances Data Bank (HSDB)cites McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug Information 93. Bethesda, MD: American Society of Hospital Pharmacists, Inc., 1993 (Plus Supplements, 1993)., p. 396
Odor: Odorless[2]
Melting point: 174 to 176 °C (345 to 349 °F, NTP 1992)[1]
Solubility in water: Slightly soluble in alcohol.[2]
3 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– greater than or equal to 100 mg/mL at 66 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–shown Slightly soluble in alcohol. [2] Hazardous Substances Data Bank (HSDB)cites McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug Information 93. Bethesda, MD: American Society of Hospital Pharmacists, Inc., 1993 (Plus Supplements, 1993)., p. 396
– In water, 142 mg/mL at 25 °C [2] Hazardous Substances Data Bank (HSDB)cites McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug Information 93. Bethesda, MD: American Society of Hospital Pharmacists, Inc., 1993 (Plus Supplements, 1993)., p. 396
log P: log Kow = -1.85[2]

Value	As written	Source
–	Ribavirin is a white powder. Exists in two polymorphic forms. (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–shown	White crystalline powder	[2] Hazardous Substances Data Bank (HSDB)cites McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug Information 93. Bethesda, MD: American Society of Hospital Pharmacists, Inc., 1993 (Plus Supplements, 1993)., p. 396

Value	As written	Source
–	greater than or equal to 100 mg/mL at 66 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–shown	Slightly soluble in alcohol.	[2] Hazardous Substances Data Bank (HSDB)cites McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug Information 93. Bethesda, MD: American Society of Hospital Pharmacists, Inc., 1993 (Plus Supplements, 1993)., p. 396
–	In water, 142 mg/mL at 25 °C	[2] Hazardous Substances Data Bank (HSDB)cites McEvoy, G.K. (ed.). American Hospital Formulary Service - Drug Information 93. Bethesda, MD: American Society of Hospital Pharmacists, Inc., 1993 (Plus Supplements, 1993)., p. 396

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 17
Rings: 2
Aromatic rings: 1
Fraction sp³ carbons (Fsp3): 0.62
H-bond donors: 4
H-bond acceptors: 7
Rotatable bonds: 3
TPSA (Å²): 143.7 computed here · PubChem 144
Formal charge: 0
XLogP3: -1.8 PubChem
Complexity: 304 PubChem
Stereocenters: 4 definedCIP: C9: R · C11: R · C14: S · C16: R
Double-bond geometry: None specified
Point group: C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C39.35%
H4.95%
N22.94%
O32.76%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: -3.01 Crippen (Wildman and Crippen 1999)
log S (water solubility): 0.52 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 3.87 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 244.21
log P ≤ 5 (Crippen): -3.01
H-bond donors ≤ 5: 4
H-bond acceptors ≤ 10: 7

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Danger

Most widely reported: 114 company reports to ECHA. Source [3].

Harmful or irritant
Health hazard

H317May cause an allergic skin reaction (47.4% of reports)
H319Causes serious eye irritation (49.1% of reports)
H335May cause respiratory irritation (57.9% of reports)
H341Suspected of causing genetic defects (58.8% of reports)
H360May damage fertility or the unborn child (51.8% of reports)
H361Suspected of damaging fertility or the unborn child (48.2% of reports)
H373May causes damage to organs through prolonged or repeated exposure (48.2% of reports)
H412Harmful to aquatic life with long lasting effects (47.4% of reports)

Precautionary statements: P203, P260, P261, P264+P265, P271, P272, P273, P280, P302+P352, P304+P340, P305+P351+P338, P318, P319, P321, P333+P317, P337+P317, P362+P364, P403+P233, P405, P501

First aid

Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. If symptoms (such as redness or irritation) develop, immediately transport the victim to a hospital. Skin: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]

Storage

Commercially available ribavirin powder for inhalation solution should be stored in tight containers in a dry place at 15-25 °C. ... Ribavirin inhalation solutions contain no preservatives and are stable for 24 hours when stored under sterile conditions at a room temperature of 20-30 °C. ... Ribavirin capsules or tablets should be stored at 25 °C, but may be exposed temperatures ranging from 15-30 °C. Ribavirin oral solution should be stored at 2-8 °C or at 25 °C, but may be exposed to temperatures ranging from 15-30 °C.[2]

Safety data sheets on the supplier’s page: LGC Standards, Sigma-Aldrich, Achemtek.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[3]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[4]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[5]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
[6]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[7]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.