Chemical Component Summary

FormulaC5 H5 N3 O
Molecular Weight123.11
Isomeric SMILESNC(=O)c1cnccn1

Chemical Details

Formal Charge0
Atom Count14
Chiral Atom Count0
Chiral Atomsn/a
Bond Count14
Aromatic Bond Count6
Leaving Atomsn/a

Drug Info: DrugBank

DrugBank IDDB00339 Different stereochemistry
DescriptionA pyrazine that is used therapeutically as an antitubercular agent.
  • 2-carbamylpyrazine
  • 2-pyrazinecarboxamide
  • Aldinamide
  • Pirazinamida
  • Pirazinamide
Brand Names
  • Pdp-pyrazinamide
  • Pyrazinamide
  • Rifater
  • Tebrazid Tab 500mg
  • Piraldina
Affected OrganismMycobacterium tuberculosis
IndicationFor the initial treatment of active tuberculosis in adults and children when combined with other antituberculous agents.
PharmacologyPyrazinamide kills or stops the growth of certain bacteria that cause tuberculosis (TB). It is used with other drugs to treat tuberculosis. It is a highly specific agent and is active only against <i>Mycobacterium tuberculosis</i>. In vitro and in vivo, the drug is active only at a slightly acid pH. Pyrazinamie gets activated to Pyrazinoic acid in the bacilli where it interferes with fatty acid synthase FAS I. This interferes with the bacteriums ability to synthesize new fatty acids, required for growth and replication.
Mechanism of actionPyrazinamide diffuses into M. tuberculosis, where the enzyme pyrazinamidase converts pyrazinamide to the active form pyrazinoic acid. Under acidic conditions, the pyrazinoic acid that slowly leaks out converts to the protonated conjugate acid, which is thought to diffuse easily back into the bacilli and accumulate. The net effect is that more pyrazinoic acid accumulates inside the bacillus at acid pH than at neutral pH. Pyrazinoic acid was thought to inhibit the enzyme fatty acid synthase (FAS) I, which is required by the bacterium to synthesise fatty acids. However, this theory was thought to have been discounted (PMID: 11914348). However, further studies reproduced the results of FAS I inhibition as the putative mechanism first in whole cell assay of replicating M. tuberculosis bacilli which have shown that pyrazinoic acid and its ester inhibit the synthesis of fatty acids (PMID: 17101678). This study was followed by in vitro assay of tuberculous FAS I enzyme that tested the activity with pyrazinamide, pyrazinoic acid and several classes of pyrazinamide analogs. Pyrazinamide and its analogs inhibited the activity of purified FAS I (PMID: 17485499). It has also been suggested that the accumulation of pyrazinoic acid disrupts membrane potential and interferes with energy production, necessary for survival of M. tuberculosis at an acidic site of infection. Pyrazinoic acid has also been shown to bind to the ribosomal protein S1 (RpsA) and inhibit trans-translation. This may explain the ability of the drug to kill dormant mycobacteria (PMID: 21835980).
Route of administrationOral
  • Anti-Bacterial Agents
  • Anti-Infective Agents
  • Antiinfectives for Systemic Use
  • Antimycobacterials
  • Antitubercular Agents
  • J04AM06
  • J04AK01
  • J04AM05
CAS number98-96-4

Drug Targets

NameSequence SearchPharmacological ActionActions
Drug Info/Drug Targets: DrugBank 3.0: a comprehensive resource for 'omics' research on drugs. Knox C, Law V, Jewison T, Liu P, Ly S, Frolkis A, Pon A, Banco K, Mak C, Neveu V, Djoumbou Y, Eisner R, Guo AC, Wishart DS. Nucleic Acids Res. 2011 Jan; 39 (Database issue):D1035-41. | PMID:21059682