KANAMYCIN

Описание

Kanamycin A belongs to the family on aminoglycoside antibiotics which consist of two or more aminosugars linked by glycosidic bonds to an aminocyclitol ring. It was isolated in Japan from Streptomyces kanamyceticus. Clinically, kanamycin is used as a sulfate. Currently, kanamycin is only rarely used; its main place is for the treatment of tuberculosis caused by multidrug-resistant Myobacterium tuberculosis strains .

Химические свойства

solid

Показания

Kanamycin A is similar to streptomycin and neomycines and has a broad spectrum of antimicrobial action. It is active with respect to most Gram-positive as well as Gram-negative microorganisms (staphylococci, gastric bacilli, rabbit fever, Fridlender’s bacillus, proteus, shigella, salmonella).
It is used for treating sepsis, meningitis, osteomyelitis, periotonitis, pneumonia, pyelonephritis, pyelocystitis, infected wounds, and post-operational purulent complications caused by microorganisms sensitive to the drug. Synonyms of this drug are karmycin, kamaxin, resistomycin, and many others.

Биологическая активность

Kanamycin is considerably broader in spectrum than streptomycin, kanamycin is more effective against gram-negative bacilli (other than Pseudomonas) and also is effective to a degree against Staph. aureus. However, it is ineffective against streptococci and pneumococci. The availability of penicillinase-resistant penicillins and cephalosporins essentially obsoleted kanamycin as the primary drug in the treatment of staphylococcal infections. Kanamycin has been essentially replaced by gentamicin and other aminoglycosides which are less ototoxic (adverse to hearing), and which also have a wider range of antibacterial activity.

Механизм действия

Kanamycin and other aminoglycoside antibiotics interfere with bacterial protein synthesis. The drug binds to a particular protein or proteins of the 30S subunit of bacterial ribosomes. This results in a misreading (or miscoding) of mRNA codons. Consequently, wrong amino acids are incorporated into growing peptide chains and nonsense bacterial proteins are formed. This effect alone may not be lethal to bacteria, yet kanamycin and other aminoglycosides are rapidly bactericidal. Numerous hypotheses have been put forward over the years to explain this. The bactericidal property may be related to the very tight binding of aminoglycosides to the ribsomes, which is essentially irreversible. The most likely explanation seems to be that kanamycin also leads to the production of abnormal membrane proteins of the bacterial cell, which cause alterations in membrane permeability, and this plays an essential role in the bactericidal action.

взаимодействия лекарств

All aminoglycosides are partially inactivated by high concentrations of any of the penicillins. In vitro, the penicillins inactivate kanamycin to about the same degree as gentamicin and tobramycin, but this occurs less readily with amikacin. Studies with gentamicin and amikacin have shown that heparin reversibly inhibits aminoglycoside activity in a dose-dependent way. This may also apply to kanamycin. Specimens for kanamycin measurements should not be obtained in heparinized tubes. Kanamycin excretion is not affected by probenecid.