Antibiotics - Aminoglycosides: Nursing pharmacology

Aminoglycosides are a class of antibiotics used to treat severe systemic infections caused by aerobic, Gram negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and the Enterobacter species.

Additionally, aminoglycosides can be effective against certain Gram positive bacteria when used in combination with cell-wall inhibitors, like penicillins or cephalosporins.

Now, aminoglycoside antibiotics used to treat bacterial infections include streptomycin, amikacin, gentamicin, tobramycin, and neomycin. These medications are poorly absorbed in the gastrointestinal tract, so they are primarily administered intramuscularly or intravenously.

Streptomycin and amikacin can be used in the treatment of mycobacterial infections. Gentamicin can also be applied topically to treat eye or ear infections; while tobramycin can be given topically to treat eye infections, or in a nebulized form to treat Pseudomonas infections in clients with cystic fibrosis.

Neomycin can be given orally to treat hepatic encephalopathy and before colorectal surgeries to act directly in the intestinal bacterial flora and reduce the risk of infection after surgery.

Aminoglycosides are powerful bactericidal antibiotics that work by binding to the 30S subunit of the bacterial ribosome. As a result, these medications disrupt bacterial protein synthesis and ultimately kill the bacteria.

Since aminoglycosides need to enter the bacteria in order to be effective, they may be given alongside an antibiotic that inhibits bacterial cell wall synthesis, such as beta-lactams, to facilitate access of the aminoglycoside across the cell wall.

Regarding side effects, one thing to keep in mind is that aminoglycosides have a significant post-antibiotic effect, meaning that their bactericidal activity persists for a period of time even after the antibiotic is stopped.