| Item |
Information |
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Drug Groups
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approved |
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Description
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A pyrazine that is used therapeutically as an antitubercular agent. |
| Indication |
For the initial treatment of active tuberculosis in adults and children when combined with other antituberculous agents. |
| Pharmacology |
Pyrazinamide 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 Mycobacterium tuberculosis. 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. |
| Toxicity |
Side effects include liver injury, arthralgias, anorexia, nausea and vomiting, dysuria,malaise and fever, sideroblastic anemia, adverse effects on the blood clotting mechanism or vascular integrity, and hypersensitivity reactions such as urticaria, pruritis and skin rashes. |
| Affected Organisms |
| • |
Mycobacterium tuberculosis |
|
| Biotransformation |
Hepatic. |
| Absorption |
Rapidly and well absorbed from the gastrointestinal tract. |
| Half Life |
9-10 hours (normal conditions) |
| Protein Binding |
~10% (bound to plasma proteins) |
| Elimination |
Approximately 70% of an oral dose is excreted in the urine, mainly by glomerular filtration within 24 hours |
| References |
| • |
Controlled trial of four thrice-weekly regimens and a daily regimen all given for 6 months for pulmonary tuberculosis. Lancet. 1981 Jan 24;1(8213):171-4.
[Pubmed]
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| • |
Controlled clinical trial of 4 short-couse regimens of chemotherapy (three 6-month and one 8-month) for pulmonary tuberculosis. Tubercle. 1983 Sep;64(3):153-66.
[Pubmed]
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| • |
A controlled trial of 6 months' chemotherapy in pulmonary tuberculosis. Final report: results during the 36 months after the end of chemotherapy and beyond. British Thoracic Society. Br J Dis Chest. 1984 Oct;78(4):330-6.
[Pubmed]
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| • |
Yee D, Valiquette C, Pelletier M, Parisien I, Rocher I, Menzies D: Incidence of serious side effects from first-line antituberculosis drugs among patients treated for active tuberculosis. Am J Respir Crit Care Med. 2003 Jun 1;167(11):1472-7. Epub 2003 Jan 31.
[Pubmed]
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| External Links |
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