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From Richard Harvey (series editor), Lippincott’s Illustrated Reviews: Pharmacology (LWW, 2008):
The tetracyclines are a group of closely related compounds that, as the name implies, consist of four fused rings with a system of conjugated double bonds. Substitutions on these rings are responsible for variation in the drugs’ individual pharmacokinetics, which cause small differences in their clinical efficacy.
Mechanism of action
Entry of these agents into susceptible organisms is mediated both by passive diffusion and by an energy-dependent transport protein mechanism unique to the bacterial inner cytoplasmic membrane. Nonresistant strains concentrate the tetracyclines intracellularly. The drug binds reversibly to the 30S subunit of the bacterial ribosome, thereby blocking access of the amino acyl-tRNA to the mRNA-ribosome complex at the acceptor site. By this mechanism, bacterial protein synthesis is inhibited”
Tetracyclines classification according to source
- Tetracycline (Ala-Tet, Brodspec, Panmycin, Sumycin, Tetracon)
- Demeclocycline (Declomycin)
- Doxycycline (Adoxa, Atridox, Doryx, Monodox, Vibramycin)
- Minocycline (Arestin, Dynacin, Minocin, Vectrin)
Tigecycline may also be considered a tetracycline antibiotic, though it is usually classified as a glycylcycline antibiotic.