Recognize the complications of Aminoglycosides

Explanation

Aminoglycoside antibiotics are extremely useful in serious infections. Unfortunately they have a very narrow therapeutic index. The most important question asked on them is the adjustment of the dose amount and dose interval based on the Trough and peak levels.

There are 2 levels measured - the peak and the trough. The peak level  is measured 1 hour after the 3rd dose is given and the trough is measured just before the next dose (4th dose) is given.

Higher the amount in each dose, higher will be the peak. The efficacy is related to its peak level.  If it is found to be lower than the recommended value, please increase the dose of each shot to ensure that the person gets the most benefit from the drug (It also improves the post antibiotic effect of Aminoglycosides).

The toxicities of Aminoglycosides are related to its trough level. This is related to the time interval between doses (Shorter the interval, higher the troughs & higher the chances of toxicity therefore if troughs are too high, please increase the interval between the doses to decrease the trough and its related toxicities).

The toxicities of Aminoglycosides are:

Renal failure - due to tubular necrosis that can be reduced in the presence of antipseudomonal penicillins.

Muscle weakness: Direct Neuro muscular junction blockade therefore cautioned in Myasthenia.

Deafness due to cochlear toxicity

Vertigo - vestibular toxicity
Complications can be prevented by good hydration and monitoring the trough levels.