Aminoglycosides

Aminoglycosides bind the 16S rRNA of the bacterial 30S ribosomal subunit, so the ribosome misreads mRNA and builds faulty proteins, and the bacteria die. Killing grows with peak concentration and goes on after levels fall (a post-antibiotic effect), which suits once-daily dosing. Anaerobes resist them, and with a cell wall agent such as a penicillin they act synergistically.

• GentamicinWHO lists it, like ampicillin and benzylpenicillin, as a first-choice Access antibiotic for sepsis in newborns and children, and as a second choice for gonorrhea.
• AmikacinAmikacin mainly damages hearing rather than balance. An inhaled liposomal form is licensed for Mycobacterium avium complex (MAC) lung disease that persists after 6 months of standard treatment.

• Serious Gram-negative infections and sepsis
• Complicated urinary tract infections and pyelonephritis
• Infective endocarditis, with a beta-lactam
• Serious respiratory infections, including pneumonia
• High-risk febrile neutropenia
• Drug-resistant tuberculosis (amikacin)

• Kidney injury (nephrotoxicity)Known forSerious
• Hearing loss, tinnitus and loss of balanceKnown forSerious
• Neuromuscular blockade and breathing paralysisKnown forSerious
• Worsening of myasthenia gravisSerious
• Numbness, tingling and muscle twitching
• SeizuresSerious
• Low magnesium (hypomagnesemia)
• Deafness in babies exposed in the wombSerious
• C. difficile colitisSerious
• Allergic reactions, including to sulfite additives

What the class has in common. Each drug's card has its own, and Known for marks what an exam expects you to know.

• Monitor blood levels, kidney function and hearing; high troughs, long courses, dehydration and older age raise the risk of toxicity.
• Avoid other ear- or kidney-toxic drugs such as vancomycin, cisplatin and amphotericin B, and loop diuretics such as furosemide.
• They deepen neuromuscular block from anesthetic muscle relaxants and can worsen myasthenia gravis; calcium salts may reverse the block.
• Carriers of the mitochondrial MT-RNR1 m.1555A>G variant can lose hearing even at normal levels, so other antibiotics are preferred.

Written for biofideX in plain words, after checking these references:

• Aminoglycoside Antibiotic (NCI Thesaurus)
• Gentamicin sulfate injection: label (DailyMed)
• Amikacin sulfate injection: label (DailyMed)
• Gentamicin 40 mg/ml solution for injection or infusion: SmPC (emc)
• WHO Model List of Essential Medicines, 24th list (2025) (WHO)

For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.