Tobramycin (eye)

Introduction

Written by Melanie Sangobowale PharmD
Medically reviewed by Melissa Badowski, PharmD, MPH, FCCP
Updated on September 26, 2023

Tobramycin (toe bra MYE sin) is a generic medication prescribed for eye infection and various other conditions. Tobramycin belongs to a group of drugs called aminoglycosides.

The Food and Drug Administration (FDA) has approved tobramycin to:

• treat bacterial eye infections
• treat sepsis 
• treat lower respiratory tract infections, such as pneumonia and bronchitis
• treat meningitis 
• treat certain abdominal infections, such as peritonitis
• treat skin, bone, and skin structure infections, such as cellulitis  
• treat urinary tract infections (UTIs)
• manage cystic fibrosis

These approved uses differ based on the form of tobramycin your doctor prescribes.

This article doesn’t provide coupons for all forms of tobramycin. To find coupons for tobramycin injection, see this article.

Boxed warnings

Tobramycin has boxed warnings, which are the most serious warnings from the Food and Drug Administration (FDA). These include:

• risk of serious kidney damage with tobramycin injection
• risk of hearing or balance problems with tobramycin injection
• risk of neuromuscular blockage with tobramycin injection
• risk of fetal harm with tobramycin injection

For details, see the “Interactions and warnings for tobramycin” section.

Side effects of tobramycin

Tobramycin may cause mild or serious side effects. More common mild side effects of tobramycin and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about tobramycin’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for tobramycin listed in the “Resources” section.

Mild side effects

More common mild side effects reported with some forms of tobramycin are listed below. These side effects may differ based on the form of tobramycin you’re prescribed.

This article doesn’t include all possible mild side effects of the drug. To learn more about tobramycin’s side effects based on the form, refer to the prescribing information for tobramycin listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Tobramycin eye drops’ mild side effects include:

• eye irritation
• eye redness
• eyelid itching
• eyelid swelling
• mild allergic reaction*

Tobramycin inhalation solution’s† mild side effects include:

• sore throat or inflammation (swelling) of the throat
• cough
• difficulty breathing
• increased mucus production
• mild allergic reaction*

* For details about this side effect, see the “Interactions and warnings for tobramycin” section.
† Tobramycin inhalation solution is given using a nebulizer machine. This machine creates a mist that allows the medication to be delivered to the lungs. 

Serious side effects

Serious side effects of tobramycin are listed below. These side effects may differ based on the form of tobramycin you’re prescribed.

This article doesn’t include all possible serious side effects of the drug. To learn more about tobramycin’s side effects based on the form, refer to the prescribing information for tobramycin listed in the “Resources” section.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, tobramycin’s serious side effects include:

• sore throat
• worsening cough in people taking the drug for respiratory conditions
• boxed warnings:*
  • risk of serious kidney damage with tobramycin injection†
  • risk of hearing or balance problems with tobramycin injection
  • risk of neuromuscular blockage with tobramycin injection
  • risk of fetal harm with tobramycin injection
• severe allergic reaction*

* For details about this side effect, see the “Interactions and warnings for tobramycin” section.
† Tobramycin injection can be given by intravenous (IV) infusion (an injection given into your vein over time). It can also be injected into your muscle. 

Common questions about tobramycin

Below you’ll find answers to a few commonly asked questions about tobramycin.

Is it safe to use tobramycin with dexamethasone?

Yes, tobramycin and dexamethasone (Tobradex) is a combination drug that’s used to treat bacterial eye infections. A combination drug contains two or more active drugs. An active drug is an ingredient that makes the drug work.

Tobramycin is an antibiotic. It works to kill the bacteria causing the infection. Dexamethasone is a steroid. It helps to reduce inflammation (swelling), or redness and swelling in your eye.

Tobramycin eye drops and dexamethasone eye drops can also be used separately to treat various eye conditions.

For more information about this medication, talk with your doctor or pharmacist.

How does tobramycin work? And how long does it take to start working?

Tobramycin works by killing the bacteria that causes infections. It does this by stopping the bacteria from making proteins that it needs to survive. It starts to work within minutes to an hour, depending on the form that you’re prescribed.

Tobramycin eye drops start working right away and can take up to 3 days for your symptoms to ease. The inhalation solution starts to work within an hour. The injection form starts to work within minutes.

If you’d like to know more about this, talk with your doctor or pharmacist.

Uses of tobramycin

The Food and Drug Administration (FDA) approves prescription drugs such as tobramycin for certain conditions. Approved uses for tobramycin are described below. These uses differ based on the form of tobramycin you’re prescribed.

Use for eye infection

Doctors may prescribe tobramycin eye drops to treat bacterial infections in your eye. It’s used for this purpose in adults and children ages 2 months and older. It’s usually prescribed as a short-term treatment.

Eye infections can be caused by bacteria that enter the eye. Symptoms may include redness, swelling, itching, pain, and discomfort. Early treatment of an eye infection may help shorten the time that you experience these symptoms.

Use for certain infections

Doctors may prescribe tobramycin injection* for treating certain bacterial infections. It’s used for this purpose in adults and children. It’s usually prescribed as a short-term treatment.

An infection happens when germs, such as bacteria, enter your body and cause symptoms. Symptoms depend on the type of infection, but they may include fever, headache, fatigue (low energy), or nausea and vomiting.

Tobramycin injection can be used to treat:

• sepsis (a serious immune system reaction to an infection)
• lower respiratory tract infections, such as pneumonia and bronchitis
• meningitis (an infection of the tissues around the brain and spinal cord)
• certain abdominal infections, such as peritonitis
• skin, bone, and skin structure infections, such as cellulitis
• urinary tract infections (UTIs)

Doctors will likely not prescribe tobramycin injection in certain situations, such as to initially treat certain urinary tract infections.

* Tobramycin injection can be given by intravenous (IV) infusion (an injection given into your vein over time). It can also be injected into your muscle. 

Use for cystic fibrosis

Doctors may prescribe tobramycin inhalation solution* and tobramycin injection to manage cystic fibrosis. For this purpose, tobramycin inhalation solution can be used in adults and children ages 6 years and older. Tobramycin injection can be used in adults and children of any age for this purpose.

With cystic fibrosis, a genetic mutation (change) in your DNA causes the buildup of thick mucus in your organs and tissues. Bacteria can get caught in the mucus and cause infection. Cystic fibrosis is a condition that will likely worsen over time.

Doctors may not prescribe tobramycin inhalation solution in certain situations, such as for:

• children ages 6 years and younger
• people with reduced lung function
• people with certain bacterial infections

* Tobramycin inhalation solution is given using a nebulizer machine. This machine creates a mist that allows the medication to be delivered to the lungs. 

Interactions and warnings for tobramycin

Below, you’ll find information about tobramycin’s possible interactions and warnings.

Interactions of tobramycin

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Some forms of tobramycin have interactions, so ask your doctor to check for possible interactions before you use tobramycin. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs 
• vitamins, herbs, or supplements

Other forms of tobramycin don’t have any known interactions. But this doesn’t mean drug interactions with tobramycin won’t happen or be reported sometime. For instance, medications created at a later time could interact with these forms of tobramycin.

To learn about drug-condition interactions, see the “Warnings for tobramycin” section below.

Warnings for tobramycin

Some people should not use tobramycin, and others should use it cautiously.

Boxed warnings

Tobramycin injection has boxed warnings about the following risks. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

To learn more about these warnings, read below. You can also talk with your doctor or pharmacist.

Risk of serious kidney damage. With kidney damage, you experience a decrease in kidney function due to a high level of tobramycin in your body. This side effect was commonly reported in studies of tobramycin injection.

Symptoms may include decreased amount of urine, swelling in the legs and ankles, fatigue (low energy), and nausea.

If you have concerns about kidney damage, tell your doctor. They’ll likely recommend lab testing to check your kidney function and monitor levels of tobramycin. They may also recommend adjusting the dose or stopping tobramycin treatment.

Risk of hearing and balance problems. Hearing and balance problems were commonly reported in studies of tobramycin.

Symptoms may include:

• tinnitus (ringing in the ears)
• vertigo (feeling like you’re moving when you’re not)
• ataxia (lack of muscle coordination and management) and dizziness

If you have concerns about hearing and balance problems, tell your doctor. They’ll likely:

• recommend you have hearing tests before you start treatment
• monitor the level of drug in your system
• adjust the dose, or stop tobramycin treatment

Risk of neuromuscular blockade. With neuromuscular blockade, you experience muscle weakness. This side effect was commonly reported in studies of tobramycin.

Symptoms may include numbness, skin tingling, muscle twitching, and convulsions.

If you have concerns about neuromuscular blockade, tell your doctor. They’ll likely recommend close monitoring while taking this medication.

Risk of fetal harm. To learn more about this risk, see the “Tobramycin and pregnancy” section below.

Other warnings

Tobramycin could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether tobramycin is a safe option for you. These warnings may differ based on the form of tobramycin you’re prescribed.

Ask your doctor about specific warnings for tobramycin, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Tobramycin can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to tobramycin or any of its ingredients, your doctor will likely not prescribe tobramycin. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to tobramycin, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of tobramycin

If you use tobramycin, you should not use more tobramycin than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve used too much tobramycin, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and tobramycin

Information about tobramycin and pregnancy and breastfeeding is described below.

Tobramycin and pregnancy

Tobramycin should not be used during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before using this medication. Your doctor may suggest birth control options to use during treatment with tobramycin.

If you’re planning a pregnancy or can become pregnant, talk with your doctor about options to manage your condition during pregnancy. Together, you can discuss the risks and benefits of your treatment options and decide whether or not you should take tobramycin during pregnancy.

Risk of fetal harm

Tobramycin injection has a boxed warning about the risk of fetal harm. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

With fetal harm, there are problems with fetal development (commonly known as birth defects). This side effect was reported in studies of tobramycin injection.

Symptoms may include deafness in children who were exposed to tobramycin before birth.

If you have concerns about the risk of fetal harm, tell your doctor. They’ll likely recommend another medication that is safer to take during pregnancy.  

Tobramycin and breastfeeding

There are risks to using tobramycin inhalation solution and tobramycin injection while breastfeeding. Also, there are possible side effects with tobramycin eye drops while breastfeeding. But there are also risks with having unmanaged cystic fibrosis, infection, and other conditions during this time. (Keep in mind that tobramycin is used to treat or manage these conditions.)

For instance, tobramycin may cause loose or bloody stools and fungal infections, such as thrush, in a child who is breastfed.

If you’re planning to breastfeed, talk with your doctor about management or treatment options for your condition. Together, you can discuss the risks and benefits of your options and decide whether or not you should take tobramycin during this time. Your doctor may recommend other healthy ways to feed your child.

What to ask your doctor

Let your doctor know if you have questions about tobramycin or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• Can tobramycin be taken with other antibiotics to treat my infection?
• How long do I have to use tobramycin inhalation for treating cystic fibrosis?
• Is tobramycin safe to take if I have a hearing impairment?

Resources

• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm
• Tobramycin inhalation solution. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/5563e8af-c6c9-42a2-974d-7d364a47f00a/spl-doc
• Tobramycin injection. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/c37c251f-92e9-40f0-8b0c-00d42875d776/spl-doc
• Tobramycin ophthalmic solution. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/d7b15276-b108-4918-9563-087652722261/spl-doc

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.