These antibiotics have been around for many years. The first aminoglycoside, streptomycin, was first discovered in the 1940’s, and was the first agent used to treat tuberculosis.
Since then, many different aminoglycosides have been developed. These include drugs such as: gentamicin, amikacin, tobramycin and netilmicin.
Mechanism of action
They kill bacteria by inhibiting protein synthesis by binding to part of the ribosome. When bacteria are unable to make proteins, they die.
Route of administration
Aminoglycosides are not absorbed orally, and are therefore only used topically (in creams or ointments) or by injection – either intravenously or intramuscularly. This means that they are usually used in hospitals.
Spectrum of action
Aminoglycosides are most active against many of the Gram negative bacteria, although they do have some activity against some Gram positive organisms. However, they are most often used to treat infections with Gram- negative bacteria.
Examples of infections
- Urinary tract infections (especially if patients need to be in hospital)
- Sepsis in the abdominal cavity (burst appendix, perforate bowel etc)
- As drops or an ointment for some eye infections
Aminoglycosides can cause damage to the kidneys and/or ears, with a degree of hearing loss. They should therefore be used with care, but having said this, they are still very useful antibiotics especially for severe infections, since they kill organisms very quickly.
The toxicity issues do not apply to these agents when used topically, since very little, if any, of the agent would be absorbed into the body when they are used in this fashion.