Aminoglycosides are a class of antibiotics used mainly in the treatment of aerobic gram-negative bacilli infections, although they are also effective against other bacteria including Staphylococci and Mycobacterium tuberculosis. They are often used in combination with other antibiotics.
What are aminoglycosides used to treat?
Aminoglycosides are a class of antibiotics used mainly in the treatment of aerobic gram-negative bacilli infections, although they are also effective against other bacteria including Staphylococci and Mycobacterium tuberculosis. They are often used in combination with other antibiotics. Aminoglycosides are thought to work by inhibiting protein ...
What is the most common aminoglycoside?
Jan 26, 2020 · The aminoglycosides are broad-spectrum, bactericidal antibiotics that are commonly prescribed for children, primarily for infections caused by Gram-negative pathogens. The aminoglycosides include gentamicin, amikacin, tobramycin, neomycin, and streptomycin. Why do aminoglycosides cause nephrotoxicity?
How can we minimize the toxicity of aminoglycosides?
Apr 02, 2022 · Aminoglycosides are bactericidal antibiotics used primarily in the treatment of gram-negative infections. They irreversibly bind to the 30S subunit of bacterial ribosomes, blocking the recognition...
What do aminoglycosides do to bacteria?
A patient with a gram-negative infection is being treated with an aminoglycoside. What system should the nurse expect to be tested daily while on this medication? Renal system
Why are aminoglycosides administered for serious infections?
Aminoglycosides are a class of antibiotics used to treat serious infections caused by bacteria that either multiply very quickly or are difficult to treat. Aminoglycosides are called bactericidal antibiotics because they kill bacteria directly.Oct 20, 2015
What bacteria do aminoglycosides cover?
Aminoglycosides are useful primarily in infections involving aerobic, Gram-negative bacteria, such as Pseudomonas, Acinetobacter, and Enterobacter. In addition, some Mycobacteria, including the bacteria that cause tuberculosis, are susceptible to aminoglycosides.
What is the action of aminoglycosides?
The aminoglycosides primarily act by binding to the aminoacyl site of 16S ribosomal RNA within the 30S ribosomal subunit, leading to misreading of the genetic code and inhibition of translocation [3,4].Dec 21, 2020
Which is used with aminoglycosides to treat Pseudomonas infections?
Pseudomonas infection can be treated with a combination of an antipseudomonal beta-lactam (eg, penicillin or cephalosporin) and an aminoglycoside. Carbapenems (eg, imipenem, meropenem) with antipseudomonal quinolones may be used in conjunction with an aminoglycoside.Mar 3, 2020
How do aminoglycosides enter bacteria?
Since aminoglycosides require an active electron transport chain to enter a bacterium, anaerobic bacteria are intrinsically resistant.
What are the main indications of aminoglycosides?
Since this drug class has demonstrated effectiveness in multi-drug resistant Gram-negative pathogens, aminoglycosides are indicated for empiric therapy in patients with severe illness; this includes empiric treatment for patients with infective endocarditis, sepsis, complicated intraabdominal infections, and ...Jul 23, 2021
What is aminoglycoside antibiotic?
A substance that works against many types of bacteria and includes streptomycin, gentamicin, and neomycin. An aminoglycoside antibiotic is used to treat bacterial infections.
Are aminoglycosides used for UTI?
Aminoglycosides are an ideal drug class for single-dose treatment of UTI, as they are excreted in high concentrations in the urine, exceeding plasma concentrations by up to 100-fold within an hour after parenteral administration (7).
What is the chemical composition of aminoglycoside?
aminoglycoside, any of several natural and semisynthetic compounds that are used to treat bacterial diseases. The term aminoglycoside is derived from the chemical structure of these compounds, which are made up of amino groups (―NH2) attached to glycosides (derivatives of sugar).
Is azithromycin an aminoglycoside antibiotics?
This nomenclature system is not specific for aminoglycosides, as vancomycin is a glycopeptide antibiotic and erythromycin, clarithromycin, azithromycin are macrolides - all of which differ in their mechanism of actions.
What do aminoglycosides target?
Aminoglycosides are a class of clinically important antibiotics used in the treatment of infections caused by Gram-positive and Gram-negative organisms. They are bactericidal, targeting the bacterial ribosome, where they bind to the A-site and disrupt protein synthesis.
Is erythromycin an aminoglycoside?
The most important antibiotics with this mode of action are the tetracyclines, chloramphenicol, the macrolides (e.g. erythromycin) and the aminoglycosides (e.g. streptomycin). The aminoglycosides are products of Streptomyces species and are represented by streptomycin, kanamycin, tobramycin and gentamicin.
Why is amikacin resistant to gentamicin?
Most resistance to aminoglycosides is caused by bacterial inactivation by intracellular enzymes. Because of structural differences, amikacin is not inactivated by the common enzymes that inactivate gentamicin and tobramycin. Therefore, a large proportion of the gram-negative aerobes that are resistant to gentamicin and tobramycin are sensitive ...
What is the best antibiotic for gram positive bacteria?
Aminoglycosides are potent bactericidal antibiotics that act by creating fissures in the outer membrane of the bacterial cell. They are particularly active against aerobic, gram-negative bacteria and act synergistically against certain gram-positive organisms. Gentamicin is the most commonly used aminoglycoside, but amikacin may be particularly effective against resistant organisms. Aminoglycosides are used in the treatment of severe infections of the abdomen and urinary tract, as well as bacteremia and endocarditis. They are also used for prophylaxis, especially against endocarditis. Resistance is rare but increasing in frequency. Avoiding prolonged use, volume depletion and concomitant administration of other potentially nephrotoxic agents decreases the risk of toxicity. Single daily dosing of aminoglycosides is possible because of their rapid concentration-dependent killing and post-antibiotic effect and has the potential for decreased toxicity. Single daily dosing of aminoglycosides appears to be safe, efficacious and cost effective. In certain clinical situations, such as patients with endocarditis or pediatric patients, traditional multiple dosing is still usually recommended.
How do aminoglycosides inhibit bacterial protein synthesis?
Traditionally, the antibacterial properties of aminoglycosides were believed to result from inhibition of bacterial protein synthesis through irreversible binding to the 30S bacterial ribosome. This explanation, however, does not account for the potent bactericidal properties of these agents, since other antibiotics that inhibit the synthesis of proteins (such as tetracycline) are not bactericidal. Recent experimental studies show that the initial site of action is the outer bacterial membrane. The cationic antibiotic molecules create fissures in the outer cell membrane, resulting in leakage of intracellular contents and enhanced antibiotic uptake. This rapid action at the outer membrane probably accounts for most of the bactericidal activity. 2 Energy is needed for aminoglycoside uptake into the bacterial cell. Anaerobes have less energy available for this uptake, so aminoglycosides are less active against anaerobes.
When was streptomycin first used?
The first aminoglycoside, streptomycin, was isolated from Streptomyces griseus in 1943.
Is aminoglycoside a bactericidal?
Aminoglycosides display bactericidal, concentration-dependent killing action and are active against a wide range of aerobic gram-negative bacilli. They are also active against staphylococci and certain mycobacteria. Aminoglycosides are effective even when the bacterial inoculum is large, and resistance rarely develops during the course of treatment.
Why is aminoglycoside activity unchanged?
Because the body does not metabolize aminoglycosides, aminoglycoside activity is unchanged by induction or inhibition of metabolic enzymes , such as those in the cytochrome P450 system. Certain medications may increase the risk of renal toxicity with aminoglycoside use ( Table 3 ).
What is the most commonly used aminoglycoside?
Gentamicin is the most commonly used aminoglycoside, but amikacin may be particularly effective against resistant organisms. Aminoglycosides are used in the treatment of severe infections of the abdomen and urinary tract, as well as bacteremia and endocarditis.
Aminoglycosides
Aminoglycosides are bactericidal antibiotics used primarily in the treatment of gram-negative infections. They irreversibly bind to the 30S subunit of bacterial ribosomes, blocking the recognition step in protein synthesis and causing misreading of the genetic code. The ribosomes separate from the messenger RNA; cell death ensues.
Gentamicin
Gentamicin has activity against various aerobic gram-negative bacteria, as well as E faecalis and staphylococcal species. It is the only aminoglycoside with appreciable activity against gram-positive organisms.
Plazomicin (Zemdri)
Semisynthetic aminoglycoside antibacterial derived from sisomicin.
Medical uses
Mechanism of action
- Traditionally, the antibacterial properties of aminoglycosides were believed to result from inhibition of bacterial protein synthesis through irreversible binding to the 30S bacterial ribosome. This explanation, however, does not account for the potent bactericidal properties of these agents, since other antibiotics that inhibit the synthesis of proteins (such as tetracycline) are no…
Pathophysiology
- Aminoglycosides are poorly absorbed from the gastrointestinal tract. After parenteral administration, aminoglycosides are primarily distributed within the extracellular fluid. Thus, the presence of disease states or iatrogenic situations that alter fluid balance may necessitate dosage modifications. When used parenterally, adequate drug concentrations are typically foun…
Pharmacology
- P. aeruginosa may show adaptive resistance to aminoglycosides. This occurs when formerly susceptible populations become less susceptible to the antibiotic as a result of decreased intra-cellular concentrations of the antibiotic. This decrease may result in colonization, slow clinical response or failure of the antibiotic despite sensitivity on in vitro testing.6
Treatment
- Aminoglycosides are often combined with a beta-lactam drug in the treatment of Staphylococcus aureus infection. This combination enhances bactericidal activity, whereas aminoglycoside monotherapy may allow resistant staphylococci to persist during therapy and cause a clinical relapse once the antibiotic is discontinued.1
Clinical significance
- Infective endocarditis that is due to enterococci with high levels of resistance to aminoglycosides is becoming increasingly common. All enterococci have low-level resistance to aminoglycosides because of their anaerobic metabolism. In the treatment of bacterial endocarditis, a beta-lactam drug is also used synergistically to facilitate aminoglycoside penetration into the cell. When hig…
Side effects
- As with all antibiotics, resistance to aminoglycosides is becoming increasingly prevalent. Repeated use of aminoglycosides, especially when only one type is employed, leads to an increased incidence of resistance.8 Nevertheless, resistance to aminoglycosides requires long periods of exposure or very large inocula of organisms and occurs less frequently than with othe…
Interactions
- Because the body does not metabolize aminoglycosides, aminoglycoside activity is unchanged by induction or inhibition of metabolic enzymes, such as those in the cytochrome P450 system. Certain medications may increase the risk of renal toxicity with aminoglycoside use (Table 3).
Toxicity
- The toxicities of aminoglycosides include nephrotoxicity, ototoxicity (vestibular and auditory) and, rarely, neuromuscular blockade and hypersensitivity reactions. Nephrotoxicity receives the most attention, perhaps because of easier documentation of reduced renal function, but it is usually reversible.
Diagnosis
- Nephrotoxicity results from renal cortical accumulation resulting in tubular cell degeneration and sloughing. Examination of urine sediment may reveal dark-brown, fine or granulated casts consistent with acute tubular necrosis but not specific for aminoglycoside renal toxicity.10 Although serum creatinine levels are frequently monitored during aminoglycoside use, an elevati…
Contraindications
- In order to minimize toxicity, family physicians should remember a few key considerations. (1) Aminoglycosides should be used only when their unique antibiotic potency is needed, such as treatment of infection in critically ill patients, and in nosocomial infections or infections with organisms resistant to less toxic therapies. (2) The clinician should change to a potentially less t…
Mechanism
- Aminoglycoside antibiotics exhibit rapid concentration-dependent killing action.5,11 Increasing concentrations with higher dosages increases both the rate and the extent of bacterial cell death. In addition, aminoglycosides have demonstrated persistent suppression of bacterial growth after short exposure, a response referred to as the post-antibiotic effect.5,12 The post-antibiotic effec…
Research
- The previously mentioned principles and the distinct differences in antimicrobial activity between aminoglycosides and other anti-infectives provide support for the development of novel dosing schemes. A number of neutropenic and nonneutropenic animal models of infection have been used to evaluate once-daily dosing of aminoglycosides. Demonstrated antibacterial efficacy an…
Cost
- A comparison of the costs of single daily dosing and traditional multiple dosing should include not only the cost of the antibiotic but also the costs of labor, laboratory monitoring and drug toxicity. A pharmacoeconomic comparison of single daily dosing versus traditional dosing of gentamicin found a 54 percent reduction in drug supply and labor costs with single daily dosing…