NZ Formulary

Gentamicin (injection)


What does it do?

Gentamicin is an antibiotic used to treat bacterial infections.

Before you start

  • Tell your doctor if you have kidney problems.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

How is it given?

Gentamicin is given as an infusion or a slow injection into a vein, or as an injection into a muscle. It is usually given to you by a health professional.

What if you forget a dose?

Contact your health professional as soon as possible. Usually, the missed dose is given as soon as possible, and treatment continued as directed. 

Can you take other medicines?

Some medicines available without a prescription may react with gentamicin including:

  • anti-inflammatories, such as diclofenac (e.g. Voltaren®), ibuprofen (e.g. Nurofen®), or aspirin (e.g. Disprin®, in doses used for pain relief). These can also be found in some cold and flu medicines (e.g. Nurofen Cold and Flu®).

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

Important information continues on next page.

What side effects might you notice?

Side EffectsRecommended action

Unsteadiness, ringing in the ears, hearing loss

Peeing less or not at all

Tell your health professional immediately

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • You will need regular blood tests to check how well your kidneys are working, and to measure the amount of gentamicin in your blood to make sure you are on the right dose. You may also have your hearing tested.