Aminoglycosides: Very hydrophilic molecules, weak bases.
+
Aminoglycosides are very hydrophilic molecules and weak bases and so aren't very well absorbed in the gastrointestinal tract. They distribute poorly and are confined to mainly extracellular fluid. Elimination is performed by the kidneys and the drugs are excreted unchanged in the urine and so have very short half-lives. They also bind to renal tissue and so shouldn't be used in patients with renal failure.
−
• Not absorbed from GI tract.
−
−
• Distribute poorly (confined to extracellualr fluid mostly – volume of distribution 0.2 l/kg).
−
−
• Renally excreted – accumulate in proximal tubular cells