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Information |
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Drug Groups
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approved |
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Description
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Tetracycline is a broad spectrum polyketide antibiotic produced by the Streptomyces genus of Actinobacteria. It exerts a bacteriostatic effect on bacteria by binding reversible to the bacterial 30S ribosomal subunit and blocking incoming aminoacyl tRNA from binding to the ribosome acceptor site. It also binds to some extent to the bacterial 50S ribosomal subunit and may alter the cytoplasmic membrane causing intracellular components to leak from bacterial cells. |
| Indication |
Used to treat bacterial infections such as Rocky Mountain spotted fever, typhus fever, tick fevers, Q fever, rickettsialpox and Brill-Zinsser disease. May be used to treat infections caused by Chlamydiae spp., B. burgdorferi (Lyme disease), and upper respiratory infections caused by typical (S. pneumoniae, H. influenzae, and M. catarrhalis) and atypical organisms (C. pneumoniae, M. pneumoniae, L. pneumophila). May also be used to treat acne. Tetracycline may be an alternative drug for people who are allergic to penicillin. |
| Pharmacology |
Tetracycline is a short-acting antibiotic that inhibits bacterial growth by inhibiting translation. It binds to the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. It also binds to some extent to the 50S ribosomal subunit. This binding is reversible in nature. Additionally tetracycline may alter the cytoplasmic membrane of bacteria causing leakage of intracellular contents, such as nucleotides, from the cell. |
| Toxicity |
LD50=808mg/kg (orally in mice) |
| Affected Organisms |
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Enteric bacteria and other eubacteria |
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| Biotransformation |
Not metabolized |
| Absorption |
Bioavailability is less than 40% when administered via intramuscular injection, 100% intravenously, and 60-80% orally (fasting adults). Food and/or milk reduce GI absorption of oral preparations of tetracycline by 50% or more. |
| Half Life |
6-12 hours |
| Protein Binding |
20 - 67% protein bound |
| Elimination |
They are concentrated by the liver in the bile and excreted in the urine and feces at high concentrations in a biologically active form. |
| References |
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[Link]
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Griffin MO, Fricovsky E, Ceballos G, Villarreal F: Tetracyclines: a pleitropic family of compounds with promising therapeutic properties. Review of the literature. Am J Physiol Cell Physiol. 2010 Sep;299(3):C539-48. Epub 2010 Jun 30.
[Pubmed]
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| External Links |
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