Tobramycin

What is tobramycin?

Tobramycin is an aminoglycoside antibiotic used to treat infections. Tobramycin is available as a clear liquid given by a vein (IV), as eye drops, as an eye ointment, and as an inhaled solution (called Tobi^®).

Laboratory testing for tobramycin

The staff will measure the amount of tobramycin in your blood shortly after you receive IV tobramycin. These blood tests tell the staff whether you are receiving an effective dose of tobramycin and help decrease the chance for side effects.

A few patients (about 1 in 500 patients) are at very high risk of developing hearing loss as a side effect of tobramycin. A genetic test called mt-RNR1 can be done to find out if you have an increased risk of developing hearing loss from tobramycin. If the test finds that you have this increased risk, your doctor may consider using another medicine to treat your infection. To learn more about mt-RNR1 and tobramycin, talk with your doctor or pharmacist, and see “Do You Know… mt-RNR1 and aminoglycosides.” For more details, go to stjude.org/pg4kds.

Possible side effects of IV tobramycin

• Decreased kidney function
• Feeling dizzy
• Trouble standing
• Hearing a roaring noise
• Loss of hearing
• Muscle twitching or feeling weak
• Need to urinate less
• Diarrhea
• Nausea
• Vomiting
• Upset stomach
• Allergic reaction with these symptoms: rash, hives, itching, chills, fever, short of breath, muscle aches, swelling of the face or neck, headache, tight feeling in throat, or coughing

Possible side effects of tobramycin (eye drops and eye ointment)

• Irritated eye that was not present before using this medicine
• Burning or stinging of the eye
• Tearing
• Blurred vision for the first few minutes after using this medicine. If the blurred vision continues, tell your doctor.

Possible side effects of inhaled tobramycin (Tobi)

• Headache
• Cough
• Sore throat, change in voice
• Change in taste
• Noisy breathing

These are the most common side effects, but there may be others. Please report all side effects to the doctor or nurse. In case of a severe side effect or reaction, call the doctor, nurse, or pharmacist at 901-595-3300. If you are outside the Memphis area, dial toll-free 1-866-2STJUDE (1-866-278-5833).

Special instructions for tobramycin

• If you are not urinating as often as usual (decreased kidney function), tell your doctor before you receive the IV form of tobramycin.
• Tell your doctor right away if you are not urinating as often as usual while you are receiving IV tobramycin.
• If you are an outpatient receiving IV tobramycin through a portable pump (such as an Eclipse^® device) follow these guidelines:
  • Finish all doses of tobramycin as your doctor instructed, even if you think your condition has improved.
  • Store tobramycin in the refrigerator or on ice.
  • Place one (1) dose of tobramycin at room temperature about one (1) hour before the dose is given.
• Tell your doctor right away if you have any changes in hearing while you are receiving tobramycin.
• While you are receiving IV tobramycin, it is important to stay well-hydrated. If you are not receiving IV fluids, drink plenty of fluids. Ask your doctor, nurse, or pharmacist how much fluid you should have each day.
• Some medicines may make the side effects of IV tobramycin worse. These medicines include furosemide, cyclosporine, amphotericin B or Ambisome®, tacrolimus, cephalosporin antibiotics (such as Cefepime® and Ceftazidime®), cisplatin, and carboplatin.
• Tell your doctor if you are taking any of these medicines, or if you start taking any new medicines while you are receiving tobramycin.
• If you are using tobramycin for an eye infection, follow these guidelines:
  • Do not let the tip of the ointment tube or eye drop bottle touch your eye or anything else while the cap is off.
  • Tilt your head back to place the medicine in your eye.
  • Use your finger to pull down the lower lid of your eye to form a pocket.
  • Squeeze the prescribed amount of ointment or number of drops into the pocket between the lower lid of the eye and the eyeball.
  • Gently close your eye, and keep it closed for about one (1) minute.
  • Store the tobramycin eye ointment or eye drops at room temperature in a dry place.
• If you are using inhaled tobramycin, follow these guidelines:
  • Use a machine called a nebulizer to breathe in the solution. Your doctor or nurse will teach you how to use the machine.
  • Do not use the solution if it is cloudy, leaking, or has particles.
  • If you are taking more than one inhaled medicine, do not mix together in the nebulizer. Talk to your doctor about the order to give inhaled medicine.
  • Store solution in a refrigerator or at room temperature. If stored at room temperature, throw away any unused containers after 28 days. Keep in foil pouch until use to protect from light.  Do not freeze solution.
  • The solution may turn a little darker if stored at room temperature. This does not affect how the medicine works.