What are aminoglycosides, and what are they used for?
Aminoglycosides are a family of antibiotic medications. They are used either alone, or alongside other antibiotics, to treat serious and life-threatening bacterial infections in many different parts of the body.
Examples of aminoglycosides used in the UK include:
- Gentamicin (most commonly used).
- Tobramycin.
- Amikacin.
The team looking after you have decided to give you an aminoglycoside because it will be the most effective antibiotic for your infection, or because there is a reason you cannot have other antibiotics.
They are mostly given into a vein as a drip (through a cannula in your vein), or sometimes as an injection. The dose you are given depends on what kind of infection you have, your weight, and how well your kidneys are working.
What to tell us before starting an aminoglycoside?
Before we start you on this medication, it is important that you, or someone who knows you well, tells us about any of the following:
- Any allergies you have and what the symptoms of this are.
- If you are or could potentially be pregnant.
- You are breastfeeding.
- If you have any conditions causing kidney disease or any kidney problems.
- If you have hearing or balance problems.
- If you have myasthenia gravis (this is a disease that causes muscle weakness).
- If you or a relative on your mother’s side have a history of a mitochondrial genetic variant (a genetic condition) or loss of hearing or balance due to antibiotic medicines.
- This is important for us to know because certain mitochondrial genetic variants may increase your risk of hearing loss with aminoglycosides.
- If you have ever been told that you cannot have an aminoglycoside antibiotic.
We will also ask you about your current medications that you are taking, including any that you buy without a prescription (over the counter) or any herbal remedies. Some medications may increase the risk of side effects with aminoglycosides so it is important that you tell us.
Sometimes, when a patient is extremely unwell due to infection (for example, patients with sepsis), antibiotics should be given within an hour of diagnosis to reduce the risk of serious complications or death. There won’t usually be time to wait until a specific type of infection has been identified, so broad spectrum antibiotics are given first. These are designed to work against a wide range of known infectious bacteria and usually cure most common infections.
If you are extremely unwell, or the above conditions aren’t documented in your medical record, the team looking after you may not be able to consider this before the aminoglycoside is given. The team will always try to confirm details with you or someone who knows you well, but sometimes this will be once your condition has stabilised. The team will then discuss the benefits and risks of continuing the aminoglycoside along with possible alternative treatments.
What side effects can aminoglycosides cause?
Like all medicines, aminoglycosides can have side effects. The following is a summary of the more serious ones. If you would like further information, please speak to the team looking after you.
Ears
It is possible for aminoglycosides to damage your ears, leading to problems with hearing and/or balance. This may show itself as feeling dizzy or difficulty in keeping your balance, a ringing in your ears or hearing loss. In some cases, this may not get better.
It is difficult to estimate the risk of these effects happening in individual patients as it depends on several factors. What we do know is that the risk of these effects increases if your kidneys do not work very well, if you have a family history on your mother’s side of a particular genetic condition affecting mitochondria (mitochondrial genetic variant), or you receive a long course of treatment.
If you notice any of the following symptoms you should tell the team treating you or your GP immediately, even if they happen months after the aminoglycoside treatment has stopped:
- Problems with your vision including blurred, jumping, bobbing, or bouncing vision.
- Problems with your balance, including unsteadiness or dizziness, particularly when you sit up, stand, or walk.
- Feeling sick and/or vomiting.
- Problems with your hearing, including new or worsening hearing loss, ringing in your ears (tinnitus), or a feeling of fullness in the ears.
If you develop any of these side effects, the team looking after you will decide whether it could be due to the aminoglycoside and may arrange for you to have your hearing and/or balance tested.
Kidneys
It is possible for aminoglycosides to damage your kidneys, making them work less efficiently. This usually gets better once the aminoglycoside is stopped. This is not usually something you will be able to notice yourself, so while you are on an aminoglycoside you will have regular blood tests to check how well your kidneys are working.
Muscles
It is possible for aminoglycosides to affect your nervous system, leading to muscle weakness. There have only been a few individual reports of this side effect, most often in patients who have been given other medications which can also affect their nervous system, such as following surgery or having spent time in intensive care. Let the team looking after you know immediately if you notice any of the following:
- Tingling of the skin.
- Numbness.
- Twitching of your muscles.
Allergy
As with any medication, it is possible to develop an allergy to aminoglycosides. If you experience any of the following signs of an allergic reaction, let the team looking after you know immediately:
- A new rash or red bumps anywhere on your body.
- Itching.
- Swelling anywhere in your body, in particular your face, lips, tongue, or throat.
- Difficulty breathing or swallowing.
How can the risk of these side effects be reduced?
If you are at increased risk of developing these side effects, we would ideally try to avoid using an aminoglycoside to treat you. However in some serious infections this may not be possible. In this situation your doctor will discuss the risks and benefits of treatment with you.
Aminoglycoside doses are carefully calculated for each individual patient to ensure you get a dose that is right for you.
The amount of aminoglycoside in your blood is measured regularly to check the dose continues to be the right one for you and adjustments made if needed.
The team looking after you will also take regular blood tests to monitor your kidney function. Based on these results the dose of the aminoglycoside, or how often you are given it, could be changed. This will reduce the risk of side effects, and make sure the medication is as effective as possible in treating your infection.
The risk of some side effects increases with longer courses of treatment, therefore the team looking after you will try to keep the course as short as is needed to treat your infection.
To reduce the risk of the aminoglycoside affecting your kidneys, you can make sure you drink plenty of water/fluids whilst you are taking the aminoglycoside.
© North Bristol NHS Trust. This edition published August 2024. Review due August 2027. NBT003703.
