Amikacin, 1 G

Amikacin, a semi-synthetic aminoglycoside antibiotic derived from kanamycin A. It works by stopping the growth of bacteria. Similar to the other aminoglycosides, amikacin disrupts bacterial protein synthesis by binding to the 30S ribosome of susceptible organisms. Binding interferes with mRNA binding and tRNA acceptor sites leading to the production of non-functional or toxic peptides.
 

The amino group of amikacin at position 1 is acylated by 4-amino-2-hydroxybutyrate. The presence of the aminohydroxybutyryl group in general prevents the enzymatic modification of amikacin at multiple positions. This antibiotic undergoes acetylation by different types of AAC(6′), as well as by a few other aminoglycoside-modifying enzymes such as AAC(2′), APH(2"), and ANT(2"). The activity of the parent antibiotic is not compromised by this synthetic alteration because the aminohydroxybutyryl group does not interfere with binding to the A-site of rRNA.
 

Amikacin is most often used for treating severe infection with multidrug-resistant, aerobic Gram-negative bacteria, especially Pseudomonas, Acinetobacter, Enterobacter, E. coli, Proteus, Klebsiella, and Serratia. The only Gram-positive bacteria that amikacin strongly affects are Staphylococcus and Nocardia.