氨基糖苷类与多肽类抗生素（Aminoglycoside and polypeptide antibiotics）.docVIP

氨基糖苷类与多肽类抗生素（Aminoglycoside and polypeptide antibiotics） Aminoglycosides: Common characteristics of aminoglycosides: 1. pharmacokinetics: fat soluble, oral absorption, injection after absorption is not easy to pass through cell membranes, mainly distributed in the extracellular fluid, the concentration in the ear, the renal cortex drug concentration is high, the blood concentration is about 10-50 times. Not metabolized in the body; excreted from urine by a prototype. 2. antibacterial spectrum: a wide range. It has bactericidal effect on aerobic gram negative bacteria and some gram positive bacteria. Streptomycin can kill Mycobacterium tuberculosis. 3. resistance: easy to produce, there is cross drug resistance between the same kind of medicine. The mechanism of production: the inactivation of enzymes mainly by bacteria. 4. mechanism of action: binding with bacterial ribosomes to interfere with the whole process of bacterial protein synthesis. * binding to the 30S subunit and interfering with the initiation stage of protein synthesis by fixing the 30S-50S ribosome complex on the mRNA initiation codon; * mRNA caused by mistranslation in conjunction with the 30S subunit, resulting in premature termination of translation, generating meaningless peptide; * forming erroneous amino acids leading to the production of nonfunctional proteins. These abnormal proteins may be inserted into the cell membrane, resulting in permeability changes and further accelerated aminoglycoside transport. These drugs have antibiotic effect, that is, the serum concentration is below the minimum inhibitory concentration, and the bactericidal activity of the residual drugs remains. 5. adverse reactions: * ototoxicity: because of the high concentration of these drugs in the inner ear in the lymph fluid, and its concentration is increased slowly, and the blood concentration decreased rapidly when the concentration of the inner ear still increased slowly, the half-life of the ear 56 times longer tha