Aminoglycosides administration route

WARNING Systemic absorption of oral route may cause neuro/oto/nephrotox may result resp paralysis possible w/ any route of administration Uses Hepatic coma, bowel prq) Action Aminoglycoside, poorly absorbed PO -1- GI bacterial flora Dose Adults. 3-12 g/24- h PO in 3-4 doses Peds. 50-1 (X) mg/kg/24 h PO in 3-4 doses Caution [C, /-] Renal failure, neuromuscular disorders, hearing impair Contra Intestinal obst Disp Tabs, PO soln SE Hearing loss w/ long-term use rash, NA EMS Use neuromuscular blockers w/ caution, reduced dose may be necessary t bleeding risk w/ concurrent anticoagulant use OD May cause neuromuscular block and kidney failure calcium salts can be used to revise neuromuscular block... 

Following intramuscular (IM) administration, drugs must cross one or more biological membranes in order to enter the systemic circulation. Intramuscular injection is used mainly for drugs and vaccines that are not absorbed orally, for example, aminoglycosides, insulin, and hepatitis vaccine. The IM route is often used for sustained medication and specialized vehicles, such as aqueous suspensions, oily vehicles, complexes and microencapsulation, which has been developed for slow delivery of drugs by this route. ... 

The most common route of administration of aminoglycosides is intravenous, though aminoglycosides can be given intramuscularly. After an intravenous infusion of an aminoglycoside, the peak serum concentration occurs after 30 minutes. Peak serum concentrations for intramuscular injections occur after 30 to 90 minutes. An intravenous dose of 1.5 mg/kg of gentamicin, tobramycin or netilmicin will result in a peak serum concentration of from 4 to 12 ug/ ml a 7.5 mg/kg dose of amikacin will produce a peak serum concentration of 20 to 35 ug/ml. 

Concentrations of aminoglycosides in secretions and tissues are low. High concentrations are found only in the renal cortex and the inner ear, likely contributing to the aminoglycosides nephrotoxicity and ototoxicity. Due to active hepatic secretion, concentrations in bile approach 30% of those found in plasma, but this represents a very minor excretory route. Penetration into respiratory secretions is poor. Diffusion into pleural and synovial fluid is relatively slow, but concentrations that approximate those in the plasma may be achieved after repeated administration. Inflammation increases aminoglycoside penetration into peritoneal and pericardial cavities. 

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