Aminoglycosides Mnemonic

This aminoglycoside antibiotic is used for gram-negative infections such as Pseudomonas and Proteus but not for Neisseria or Legionella. It can cause ototoxicity and nephrotoxicity, which limits its use clinically. It is not given orally due to its lack of absorption from the small intestine. It is often used to coat surgical implants and tools. It is also often used in combination with beta-lactams for empiric treatment of neonatal sepsis, especially for suspected gram-negative pathogens.

Neomycin is a popular topical aminoglycoside antibiotic. It is highly ototoxic and nephrotoxic and subsequently is not used as a systemic treatment. Since the intestine does not absorb it, it is used as a second-line agent (after rifaximin) to treat hepatic encephalopathy by eliminating ammonia-producing bacteria in the intestine. It is also used to reduce the risk of infection during intestinal surgery by eliminating intestinal bacteria.

This aminoglycoside is mainly used for Pseudomonas, Enterobacter, and Serratia infections, but like the other aminoglycosides, it can cause nephrotoxicity and ototoxicity. This drug cannot be given orally, and dosing should be carefully monitored in patients with renal failure. It is often used in combination with beta-lactams for empiric treatment of neonatal sepsis, especially for suspected Gram-negative pathogens.

Tobramycin is another aminoglycoside antibiotic used for gram-negative infections. It is better than gentamicin when it comes to treating pseudomonal infections of the lung, so it is used in cystic fibrosis patients during pseudomonal infections. It also cannot be given orally but has a special application as an ophthalmic solution (Tobrex) for bacterial conjunctivitis. Just like other aminoglycosides, tobramycin also causes ototoxicity and nephrotoxicity.

Streptomycin was the first aminoglycoside discovered and was used for Mycobacterium tuberculosis infections. This antibiotic is now occasionally used for endocarditis, Yersinia pestis infestation, and tuberculosis. Just like other aminoglycosides, streptomycin also causes ototoxicity and nephrotoxicity. Its use has significantly declined due to resistance and the availability of better alternatives.

Unlike bacteriostatic agents, which simply stop bacteria from reproducing, bactericidal agents actually cause bacterial cell death. Aminoglycosides bind the ribosomal subunit of bacteria and cause misreading of mRNA during protein synthesis. The production of nonfunctional proteins disrupts cell membrane integrity and key metabolic processes. They do not directly affect DNA replication, but inhibiting proper protein synthesis impairs bacterial growth and division. A higher concentration of medication leads to quicker eradication of the infection.

Aminoglycosides bind to the 30S prokaryotic ribosomal subunit and inhibit bacterial protein synthesis. This is performed by inhibiting the formation of the initiation complex required to translate bacterial mRNA.

Aminoglycosides bind to the 30S prokaryotic ribosomal subunit and are known to interfere with the proofreading process, increasing the error rate during synthesis and misreading of bacterial mRNA. This commonly leads to premature termination of protein synthesis.

Aminoglycosides require oxygen for uptake into the bacterial organism. They are ineffective against anaerobic bacteria because they require oxygen-dependent transport to enter bacterial cells. Anaerobic bacteria lack the oxygen-dependent transport system required for aminoglycoside uptake.

Aminoglycosides are typically used for aerobic gram-negative rod infections, including Pseudomonas and Enterobacter. The most frequent use of these antibiotics includes empiric therapy for serious infections, including septicemia, complicated intra-abdominal infections, UTIs, and nosocomial URIs. Gentamicin or amikacin is used in combination with ampicillin in neonates due to coverage of E. coli, Klebsiella, and Listeria monocytogenes.

Aminoglycosides are sometimes used in conjunction with beta-lactam antibiotics in streptococcal infections due to their synergistic effects, especially in the treatment of endocarditis. One of the most frequently used combinations is ampicillin and gentamicin.