Tobramycin (Ophthalmic)

Tobramycin, an effective FDA approved drug and available by prescription only, can be found in ointments and eye drops that can fight bacterial infections.


Tobramycin (ophthalmic route) is an aminoglycoside antibiotic that is also water soluble and acts on a high number of gram-positive and gram-negative organic pathogens. It has a molecular weight of 467.52.

It belongs to the drug classes, ophthalmic and aminiglycosides. It is a prescription only medication marketed in the U.S. under the following brand names:

  • Tobrex
  • Tobrasol
  • AKTob

Canadian brands available are the following:

  • Tomycine
  • Sab-Tobramycin
  • Apo-Tobramycin

It is available in the forms of solution for eye drops or ointment. Both the cream and eye drops can be used at the same time with the ointment being applied at night and the eye drops during the day. Tobramycin Ophthalmic can be used by itself or with other medications for eye infections.

Tobramycin (ophthalmic route) has been found to be effective against many strains of bacteria, including those that have developed resistance to other topical antibiotics. It is FDA approved, and the first brand received approval on December 12, 1980.

Conditions Treated

  • Bacterial eye infections

Type of Medicine

  • Antibiotic

Side Effects

Many drugs may cause varying adverse effects on different people. One person may tolerate a prescription quite well, but this may not be the case with another person. Not all adverse effects are severe, however, and they may not require immediate medical attention.

A doctor must be informed of all medicines a patient is taking to reduce the incidence of severe side effects. This information will help the doctor decide if there are any ingredients in the drugs and other products in use that can exacerbate any adverse effects.

Some side effects go away after continued use of a drug as the patient's body adjusts to the new medication. All adverse effects, however, should be reported to a medical practitioner, who should determine their seriousness.

In most instances of using tobramycin, no adverse effects requiring medical attention are reported. An adverse effect that does go away without needing to seek the advice of a doctor is burning and stinging in the eyes. Unless this becomes bothersome, it need not be reported to a doctor. A doctor or other medical professional can be informed if the problem persists. They can suggest tips to reduce the burning and stinging in the eyes or prevent it altogether.

A side effect common after application of tobramycin ointment is the patient's vision blurring for some minutes. This is a common effect after use of most creams, and should not be considered dangerous unless it persists for a long time or appears to worsen over time.

In rare cases, patients using tobramycin experience redness, itching, swelling or any other signs of irritation of the eyelid or eye. These must be symptoms which were not there before beginning use of this drug to be sure the problem is arising from the medicine. These kinds of symptoms are severe and must be reported immediately to a healthcare professional.

If a patient using this drug finds that their eyes are more sensitive to light, a doctor should be notified immediately. This is a commonly seen side effect which may be severe.

If a patient using this medicine notices no visible improvement in symptoms after some time, or symptoms appear to get worse, a healthcare professional must be notified immediately.

A patient using this antibiotic may also use too much resulting in an overdose. The signs of an overdose are the following:

  • The eyes or eyelids itch, swell or redden.
  • The eyes water more than usual.
  • The transparent part of the eye at the front becomes irritated and painful.

Immediate medical attention must be sought when an overdose is suspected. In case anyone accidentally swallows this medicine, a doctor should be informed, or a poison helpline reached at 1-800-222-1222.

A patient using tobramycin (ophthalmic route) must also be on the lookout for allergic reactions. A doctor must be informed of all the substances a patient is allergic to so that he can determine all possible sensitivities after using tobramycin.

Symptoms that indicate an allergic reaction include the following:

  • Difficulties with breathing
  • Swelling of the tongue, throat, lips, and face
  • Hives


Mild to moderate eye infection

Ointment: apply 1.25cm (1/2 inch) inside the infected eye(s) every 8-12 hours or two to three times in a day.

Solution: apply 1-2 drops every 1-2 hours in the initial 24-48 hours and then 1-2 drops every 4-6 hours.

Severe eye infection

Ointment: apply 1.25cm (1/2 inches) every 3-4 hours inside the affected eye(s)

Solution: two drops should be put inside the eye every 30 to 60 minutes, and then less frequently after improvement is noticed. In the case of Pseudomonas aeruginosa, two drops should be applied every five minutes for one hour, and then every 30 minutes.

This medicine should be used for the full duration prescribed by the doctor, even if symptoms disappear. Using the medication as instructed is the only way to clear the infection completely.


This medicine is safe for use in children. Tests done on the drug at effective doses have not found it to have any different results from when used on adults. The dosage used for children matched that used for adults.


There are no specific studies done to confirm if the results obtained when using this medicine on senior citizens are different from those when used on other adults.



  • Patients using the eye drops must thoroughly wash and dry their hands before handling the medicine. Properly washing hands ensures that the solution does not get contaminated by dirt on hands.
  • The patient should then tilt their head backward, and with the index finger of one hand, gently pull back the skin just below the eyelid of the infected eye. This will expose the inside of the eye, and the patient should then drop the necessary medicine into this space. The skin that has been pulled backward should be released and the eye gently closed. Blinking should be avoided, and the eye should be closed for one to two minutes to allow the medicine to spread within the eye.
  • If the first attempt to put a drop or two in the eye does not succeed, such as if the dose is poured on the outside of the eye, another drop should be applied.
  • To further keep the medicine as germ-free as possible, the tip of the applicator should not be allowed to touch the eye or any other surface. The medicine bottle must be well sealed.
  • If two ophthalmic solutions are to be applied to the eye, the patient should wait 5 minutes in between applications. This will allow the first medicine to spread in the eye and not be washed out by the second one.


  • Hands should be thoroughly washed before handling this medicine. Not properly cleaning hands may lead to contamination of the ointment. Such contamination may lead to further infections in the eye(s).
  • The patient should then tilt their head back and with the index finger, pull back the skin beneath the lower eyelid of the infected eye. Space will be created just above the lower eyelid.
  • A thin strip of ointment should be squeezed into this pouch. The amount used should be as advised by a doctor.
  • The eyelid should be released gently and pushed upwards to close the eye.
  • The eye should be kept closed for about two minutes for the medicine to spread.
  • The ointment should be kept as germ-free as possible by ensuring the tip of the applicator does not contact the eye or any surface.
  • The applicator tip tube should be wiped clean with a tissue after use of the ointment and the cap put back on and tightly closed.

Missed Dose

In case a dose is missed, the patient should take it as soon as they can. However, if the missed prescription is considered too close to the next dose, it should not be used. Double treatments should not be taken.


Tobramycin eye drops or ointment should not be used with Ataluren. If you are to use these two drugs together, a doctor should be notified. He should decide to prescribe a different medication, as the interaction between ataluren and tobramycin is highly clinically significant.

A patient using any one of the following drugs should inform their doctor as well. It is not recommended that any one of the following drugs should be used with tobramycin, but if this must happen, a doctor will make some adjustments to reduce the impact of interactions.

  • Alcuronium
  • Cholera Vaccine, Live
  • Atracurium
  • Colistimethate Sodium
  • Cidofovir
  • Cisatracurium
  • Lysine
  • Decamethonium
  • Doxacurium
  • Fazadinium
  • Gallamine
  • Pancuronium
  • Ethacrynic Acid
  • Foscarnet
  • Furosemide
  • Metocurine
  • Pipecuronium
  • Rapacuronium
  • Rocuronium
  • Mannitol
  • Succinylcholine
  • Hexafluorenium
  • Mivacurium
  • Vancomycin
  • Tubocurarine
  • Vecuronium

Using any one of the following drugs with tobramycin raises the risk of side effects:

  • Cyclosporine
  • Cisplatin

If it is beneficial for a patient to use any of the above two drugs with tobramycin, a doctor will adjust dosages to reduce the risk of adverse side effects.



Tobramycin eye drops and ointments can be given during pregnancy when needed. The FDA has placed the drug in Pregnancy category B. Studies done on animals in gestation showed no fetal damage or fertility impairment when doses 33 times the systemic dosage given to humans were administered. No well-controlled data on pregnant women is available.


If this drug is to be used by a nursing mother, breastfeeding should be discontinued. The manufacturer recommends discontinuation of breastfeeding when using this drug because of the potential harm it may cause to a nursing infant. There is no available data on whether tobramycin is excreted in human milk.


The eye drop or the ointment with tobramycin as the active ingredient should be stored in a closed container. It should be stored at room temperature, away from moisture, direct light, and heat. The drug should be not be frozen. It should not be refrigerated.

Like all medicines, it should be kept away from children and pets.

Any medicine that remains after treatment is complete should be discarded and not stored for future use. A pharmacist or doctor should advise on how to get rid of expired medicines.


Tobramycin ophthalmic is an antibiotic that is very effective against bacteria, including those that are penicillin resistant. It is an active antibiotic that should not be used without proper guidance from a doctor. Misuse of this drug could lead to severe problems.

As with any drug, a doctor or other healthcare professional prescribing this drug must be informed or all other medications that the patient is using. The full list of other products in use must include all prescription medications, over the counter drugs, vitamins, minerals and any other natural products. This information is vital as it will help a doctor in determining dosages to be taken and possible interactions.

In case of unexpected or unwanted side effects, a doctor must be notified immediately. A patient must never presume to treat themselves or deal with any effects of this medication. Only a doctor has the expertise to diagnose and treat any symptoms.

Using another person's drugs is worse than self-medicating. Medicine should never be shared, even among family members, or when symptoms presented are the same. Only a doctor can weigh up the myriad issues involved in prescribing a drug.

It is not possible to include all information about tobramycin here. There is still a lot of information on the tobramycin eye drops and ointments not included. The information here should not be used for diagnosis or to replace the advice of a medical practitioner. It should be consulted only for general purposes.

Tobramycin antibiotic for the eyes is very useful for the conditions indicated, but for a successful outcome using this drug, the advice of a healthcare professional must be strictly followed.

Last Reviewed:
December 22, 2017
Last Updated:
April 03, 2018
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