Aminoglycosides

Members: Streptomycin, neomycin, kanamycin, amikacin, gentamicin, netilmicin.

Pharmacokinetics: Aminoglycosides are absorbed very poorly from the intact gastrointestinal tract. After intramuscular injection, aminoglycosides are well absorbed. They are highly polar compounds that do not enter cells readily. The kidney clears aminoglycosides, and excretion is directly proportionate to creatinine clearance.

Adverse effects: Aminoglycosides damage the VIII nerve and the kidneys. Ototoxicity can manifest itself either as auditory damage, resulting in tinnitus and high-frequency hearing loss initially; or as vestibular damage, evident by vertigo, ataxia, and loss of balance. Nephrotoxicity results in rising serum creatinine levels or reduced creatinine clearance. Neomycin, kanamycin, and amikacin are the most ototoxic agents. Streptomycin and gentamicin are the most vestibulotoxic.