infectious diseases
Aminoglycosides
Pharmacokinetics
Aminoglycosides are poorly absorbed orally but are well absorbed from the peritoneum, pleural cavity, joints , and from denuded skin. Aminoglycosides are usually given IV but may be given IM if IV access is unavailable. Aminoglycosides are distributed well into extracellular fluid except for vitreous humor, cerebrospinal fluid, respiratory secretions, and bile (particularly in patients with biliary obstruction). Intravitreous injection is required to treat endophthalmitis. Intraventricular injection is often required to reach intraventricular cerebrospinal fluid levels high enough to treat meningitis. Aminoglycosides are excreted by glomerular filtration and have a serum half-life of 2 to 3 hours; the half-life increases exponentially as the glomerular filtration rate falls (eg, in renal insufficiency, in older people). 