ATC Code D06AX07, J01GB03, S01AA11, S02AA14, S03AA06
Formula C21H43N5O7
Molar Mass (g·mol−1) 477.6
Physical State solid
Melting Point (°C) 218–237
CAS Number 1403-66-3
PUB Number 3467
Drugbank ID DB00798
Solubility soluble in water


Gentamicin is an antibiotic from the group of aminoglycosides that is used to treat various types of bacterial infections. It is a mixture of substances consisting of several antibacterial compounds. These include bone infections, endocarditis, pelvic inflammatory disease, meningitis, pneumonia, urinary tract infections, and blood poisoning (sepsis). It is ineffective against gonorrhea or chlamydial infections. It can be given intravenously, by injection into a muscle, or topically. Topical formulations may be used for burns or eye infections.



Gentamicin is a bactericidal antibiotic that acts by binding to the 30S subunit of the bacterial ribosome, thereby interfering with protein synthesis. Gentamicin's binding to the ribosome prevents bacterial tRNA from fully binding to the ribosome, resulting in protein chain termination. This inhibits the growth and multiplication of the bacteria.


The oral bioavailability of gentamicin is too low for peroral administration. Therefore, gentamicin is used exclusively parenterally (injection) or on the skin. Protein binding is 0-30%. The half-life is about 3-5 hours.


Side effects

  • low blood cell counts
  • Allergic reactions
  • Neuromuscular problems
  • nerve damage (neuropathy)
  • Kidney damage (nephrotoxicity)
  • ear problems (ototoxicity)

Gentamicin can cause inner ear problems and kidney problems. The inner ear problems can cause problems with balance and hearing loss. Nephrotoxicity and ototoxicity are dose-dependent, with higher doses bringing a greater risk of side effects. These side effects may continue to occur even after gentamicin is stopped.

If used during pregnancy, it may harm the developing baby. However, use during breastfeeding is considered safe.

Toxicological data

LD50 (rat, oral): >5000 mg sulfate-kg-1

Editorial principles

All information used for the content comes from verified sources (recognised institutions, experts, studies by renowned universities). We attach great importance to the qualification of the authors and the scientific background of the information. Thus, we ensure that our research is based on scientific findings.

Markus Falkenstätter

Markus Falkenstätter

Markus Falkenstätter is a writer on pharmaceutical topics in Medikamio's medical editorial team. He is in the last semester of his pharmacy studies at the University of Vienna and loves scientific work in the field of natural sciences.

Mag. pharm Stefanie Lehenauer

Mag. pharm Stefanie Lehenauer

Stefanie Lehenauer has been a freelance writer for Medikamio since 2020 and studied pharmacy at the University of Vienna. She works as a pharmacist in Vienna and her passion is herbal medicines and their effects.

Your personal medicine assistent

afgis-Qualitätslogo mit Ablauf Jahr/Monat: Mit einem Klick auf das Logo öffnet sich ein neues Bildschirmfenster mit Informationen über Medikamio GmbH & Co KG und sein/ihr Internet-Angebot: This website is certified by Health On the Net Foundation. Click to verify.

Search our database for drugs, sorted from A-Z with their effects and ingredients.


All substances with their common uses, chemical components and medical products which contain them.


Causes, symptoms and treatment for the most common diseases and injuries.

The contents shown do not replace the original package insert of the medicinal product, especially with regard to dosage and effect of the individual products. We cannot assume any liability for the correctness of the data, as the data was partly converted automatically. A doctor should always be consulted for diagnoses and other health questions. Further information on this topic can be found here.