Aminoglycosides

Aminoglycosides are a class of antibiotics. They treat bacterial infections, especially ones from gram-negative bacteria. They’re also useful in combined treatments for antibiotic-resistant infections.

Aminoglycosides that are available in the U.S. include:

• Amikacin (Amikin™)
• Gentamicin (Garamycin®, Gentak®)
• Neomycin (Mycifradin™, Neobiotic™)
• Paromomycin (Humatin®)
• Plazomicin (Zemdri®)
• Streptomycin
• Tobramycin (Tobrex®, Tobi®, Bethkis®)

What are aminoglycosides approved for?

Aminoglycoside antibiotics mainly treat or prevent bacterial infections or infection-related conditions. These include:

• Bacterial meningitis or other infections from Haemophilus influenzae
• Blood infections (bacteremia)
• Brucellosis
• Heart inflammation from bacterial infections (infective endocarditis)
• Infections in people with weakened immune systems
• MAC infections
• Pneumonia, especially in healthcare settings
• Respiratory infections, like tuberculosis, plague or Pseudomonas aeruginosa
• Severe urinary tract infections
• Sexually transmitted infections, like chancroid and gonorrhea
• Skin infections that can happen with conditions like pustular acne, psoriasis and superficial folliculitis
• Surface eye infections, like conjunctivitis and blepharitis

Healthcare providers often combine an aminoglycoside with another type of antibiotic. Doing that makes the treatment more effective. These combinations can also overpower tougher or resistant bacteria and reduce the chance of resistance.

Aminoglycosides can also help with:

• Amoeba infections in your digestive tract
• Coma from liver dysfunction
• Cystic fibrosis
• Suppressing your intestinal bacteria (gut microbiome)

What are the major side effects of aminoglycosides?

All aminoglycosides can cause two major side effects. They are:

• Nephrotoxicity
• Ototoxicity

These usually only happen with injections of these medications. But they can sometimes happen when you take them in pill form, too.

A third side effect, neuromuscular blockade, is also possible. But it’s much less common and is easily reversible.

Ototoxicity

Ototoxicity happens when something causes toxic damage to your hearing (auditory) or balance (vestibular) systems. Along with hearing symptoms, you can experience vestibular symptoms, like:

• Headaches, usually before other symptoms and that last up to two days
• Nausea and vomiting that start after the headaches stop, and last for a week or two
• Balance problems that last about as long as the nausea and vomiting
• Vertigo, especially feeling like the world keeps moving even after you stop, or making it hard to hold still when you can’t see
• Ataxia, making it hard to walk or make any sudden movements

When it’s severe, ototoxicity can have long-lasting or even permanent effects. It can take as long as 12 to 18 months to recover from vestibular symptoms, and you might have permanent damage. But permanent damage may be preventable if caught early.

Some medicines have a higher risk of causing ototoxicity than others. But your healthcare providers can lower the odds of it happening. The medicine they prescribe, the dose you receive and how often you receive the medicine can all play a role. Your provider can tell you more about what you can expect.

Nephrotoxicity

Nephrotoxicity is when toxic effects damage your kidneys. It happens in up to 1 in 4 people.

Nephrotoxicity isn’t something you’ll notice directly. Blood tests are the best and fastest way to detect it. And fortunately, it’s almost always reversible because your body can repair the damage. Your healthcare provider can also reduce the chances of nephrotoxicity. The medicine they prescribe, its dose and how often you take it all can play a role. Your provider can tell you more about what to expect.

Neuromuscular blockade

Neuromuscular blockade is when something blocks signals as they cross from your nerves to your muscles. It’s a less common effect of aminoglycosides and usually only happens at very high doses.

This side effect can be dangerous if the affected muscles are the ones you use to breathe. Fortunately, medicines like calcium gluconate or neostigmine are fast antidotes.

Is azithromycin an aminoglycoside?

No, azithromycin isn’t an aminoglycoside. It’s a macrolide. Both types are antibiotics, but they work in different ways.

What is the difference between macrolides and aminoglycosides?

Aminoglycosides and macrolides both interfere with a process called protein synthesis. But they don’t interfere in the same way.

Protein synthesis is how bacteria make the proteins they need to stay alive. Protein synthesis has two steps: transcription and translation. Transcription is creating a template to follow while making the protein. Translation is taking the template and making the protein.

Aminoglycosides disrupt transcription. They stop the copying so the bacteria can’t make a protein template.

Macrolides disrupt translation. The active chemical in the antibiotic attaches to proteins during translation and blocks the process. It’s like sticking a wrench into a set of gears. The gears can’t turn, and the machine breaks down.

Either way, the bacteria die because they can’t make new proteins that they need to survive.

How should I take aminoglycosides?

Aminoglycosides come in many forms, including:

• Injections that a healthcare provider gives you
• Pills that you take by mouth
• Inhaled through breathing treatments
• Topical creams or ointments
• Eye drops

You should always take these medicines exactly as your provider prescribes. That makes it more likely that they’ll work properly. It also lowers the odds that the infection comes back or develops antibiotic resistance. If you have questions or don’t understand how to use them, ask your provider. They want to make sure these medicines help you and don’t cause side effects.

Can I take aminoglycosides if I’m pregnant or thinking of becoming pregnant?

If your provider recommends an aminoglycoside antibiotic, be sure to tell them if you’re pregnant or could be. There’s limited data on how these drugs might affect your pregnancy. Your provider can also tell you if there’s a risk of these medicines passing into breast milk.