The aminoglycosides. Streptomycin, kanamycin, gentamicin, tobramycin, amikacin, netilmicin, sisomicin.

Despite their toxicity, the aminoglycosides remain useful and are often the first choice in the treatment of serious infections due to gram-negative bacilli. Nephrotoxicity has restricted the indications for neomycin to topical and oral use. Emergence of resistant organisms has limited the use of streptomycin to a few specific conditions. Gentamicin, tobramycin, and amikacin are effective against a broad spectrum of gram-negative bacilli including Pseudomonas aeruginosa. Amikacin is the aminoglycoside of choice when gentamicin resistance is prevalent.