What is Gentamicin?

Gentamicin is an aminoglycoside antibiotic composed of a mixture of related gentamicin components and fractions and is used to treat many types of bacterial infections, particularly those caused by Gram-negative organisms.

It is synthesized by Micromonospora, a genus of Gram-positive bacteria widely present in the environment (water and soil). To highlight their specific biological origins, gentamicin and other related antibiotics produced by this genus (verdamicin, mutamicin, sisomicin, netilmicin, retymicin) generally have their spellings ending in ~micin and not in ~mycin. Gentamicin is a bactericidal antibiotic that works by binding the 30S subunit of the bacterial ribosome, interrupting protein synthesis.

Like all aminoglycosides, when gentamicin is given orally, it is not systemically active. This is because it is not absorbed to any appreciable extent from the small intestine. It is administered intravenously, intramuscularly or topically to treat infections. It appears to be completely eliminated unchanged in the urine. Urine must be collected for many days to recover all of a given dose because the drug binds avidly to certain tissues.

E. coli has shown some resistance to gentamicin, despite being Gram-negative. Reluctance to use gentamicin for empirical therapy has led to increased use of alternative broad-spectrum antibiotics, which some experts suggest has led to the prevalence of antibiotic-resistant bacterial infections by MRSA and other so-called "superbugs".

Gentamicin is one of the few heat-stable antibiotics that remain active even after autoclaving, which makes it particularly useful in the preparation of some microbiological growth media. It is used during orthopaedic surgery when high temperatures are required for the setting of cements (e.g. hip replacements).

It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.