Tobramycin

Tobramycin is a prescription medication used to treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that surround the brain and spinal cord) and infections of the blood, abdomen (stomach area), lungs, skin, bones, joints, and urinary tract. Tobramycin can also be used to treat eye infections.

Tobramycin belongs to a group of drugs called aminoglycoside antibiotics. These work by killing bacteria that cause infections.

This medication comes in solution form to be instilled into the eye and in ointment form to be applied to the eyes. For eye infections, tobramycin solution is usually used every 4 hours and the ointment is applied 2 to 3 times a day.

Tobramycin is also available as a capsule and as a solution for inhalation. It is administered 2 times a day.

This medication is also available in an injectable form to be given directly into a vein (IV) or a muscle (IM) by a healthcare professional.

Common side effects of tobramycin include upset stomach, pain at the injection site, fever, and headache.

Tobramycin can also cause dizziness. Do not drive or operate heavy machinery until you know how tobramycin affects you.

Topical:

Tobramycin is a prescription medication used to treat infections of the eyes that care caused by bacteria.

Inhalation:

Tobramycin is a prescription medication used to treat infections of the respiratory tract that care caused by bacteria in patients with cystic fibrosis.

Injectable:

Tobramycin is a prescription medication used to treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that surround the brain and spinal cord) and infections of the blood, abdomen (stomach area), lungs, skin, bones, joints, and urinary tract.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Tobramycin may be found in some form under the following brand names:

• Bethkis

• Kitabis Pak

• Nebcin

• Nebcin Pediatric

• Tobi

• Tobradex

• Tobraflex

• Tobrex

• Tomycine

• Zylet

Serious side effects have been reported with Tobramycin. See the “Tobramycin Precautions” section.

Topical:

Common side effects of tobramycin for the eyes include tearing or swelling of the eye and irritation of the eye. The ointment may cause temporary blurred vision.

Inhalation:

Common side effects of tobramycin for inhalation include voice changes and ringing in the ears.

Injectable:

Common side effects of injectable tobramcyin include:

• nausea
• vomiting
• diarrhea
• pain at the injection site
• headache
• fever

This is not a complete list of tobramycin side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• other antibiotics such as amoxicillin (Amoxil, Larotid, Moxatag, in Augmentin, in Prevpac), ampicillin, or penicillin
• dimenhydrate (Dramamine)
• meclizine (Bonine)
• nonsteroidal anti-inflammatory drugs such as indomethacin (Indocin, Tivorbex)

This is not a complete list of tobramycin drug interactions. Ask your doctor or pharmacist for more information.

Topical:

Serious side effects have been reported with tobramycin for the eyes including:

• eye tearing
• itching, stinging, or burning of the eye
• swelling of the eye
• temporary blurred vision (from the ointment)

Inhalation:

Serious side effects have been reported with tobramycin for inhalation including:

• hoarseness
• voice changes
• tinnitus (ringing in the ears)

Injectable:

Serious side effects have been reported with injectable tobramycin including the following:

• Nephrotoxicity (kidney damage). Tell your healthcare provider right away if you experience decreased urine production.
• Neurotoxicity (damage to the nervous system). Tell your healthcare provider right away if you experience any of the following symptoms:
  • dizziness
  • vertigo
  • tinnitus
  • roaring in the ears
  • hearing loss

Tobramycin can cause other serious side effects. Tell your healthcare provider right away if you experience any of the following symptoms:

• lethargy or decreased energy
• confusion
• depression
• disorientation
• rash
• itching
• hives
• peeling or blistering of the skin
• fever
• headache
• nausea
• vomiting

Tobramycin can cause dizziness. Do not drive or operate heavy machinery until you know how tobramycin affects you.

Do not take tobramycin if you are allergic to tobramycin or to any other aminoglycoside antibiotics amikacin, kanamycin, neomycin, paromomycin, streptomycin, or gentamicin.

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of tobramycin, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking tobramycin, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to tobramycin or to any of its ingredients
• are allergic to other aminoglycoside antibiotics such as amikacin, kanamycin, neomycin, paromomycin, streptomycin, or gentamicin
• have cystic fibrosis
• have problems with your muscles, including conditions such as myasthenia gravis or Parkinson’s disease
• are pregnant or breastfeeding

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X - are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Tobramycin for injection and tobramycin for inhalation fall into category D. It has been shown that use of tobramycin in pregnant women caused some babies to be born with problems. However, in some serious situations, the benefit of using this medication may be greater than the risk of harm to the baby.

Topical tobramycin for the eyes falls into category B. There are no well-done studies that have been done in humans with tobramycin. In animal studies, pregnant animals were given this medication, and the babies did not show any medical issues related to this medication.

Tell your doctor if you are breastfeeding or plan to breastfeed.

After maternal injection, tobramycin has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from tobramycin, a choice should be made whether to stop nursing or to stop use of this medication. The importance of the drug to the mother should be considered.

Maternal use of topical formulations for the eye that contain tobramycin presents little or no risk for the nursing infant.

Take tobramycin exactly as prescribed.

Topical:

This medication comes in solution form to be instilled into the eye and in ointment form to be applied to the eyes. For eye infections, tobramycin solution is usually used every 4 hours and the ointment is applied 2 to 3 times a day.

Inhalation:

Tobramycin is also available as a capsule and as a solution for inhalation. It is administered 2 times a day.

Injectable:

This medication is also available in an injectable form to be given directly into a vein (IV) or a muscle (IM) by a healthcare professional.

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take 2 doses of tobramycin at the same time.

Topical:

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• the condition being treated
• how you respond to this medication

For mild to moderate eye infections, the recommended dose of tobramycin is ½-inch of ointment applied to the affected eye(s) 2 to 3 times daily or 1 to 2 drops into the affected eye every 4 hours. For severe infections, the same dose of the ointment can be administered every 3 to 4 hours, and the dose of the drops may be increased to 2 drops every 4 hours.

The ointment for use in the eyes should not be used on the skin.

Inhalation:

The dose your doctor recommends may be based on the following:

• the condition being treated
• other conditions you have

The recommended dose of tobramycin capsules for inhalation for the treatment of respiratory infections in people with cystic fibrosis is four 28-mg capsules 2 times a day for 28 days. The capsules should not be swallowed whole; the contents of the capsule are for oral inhalation and should only be used with the appropriate inhaler device. The recommended dose of tobramycin solution for inhalation is 300 mg 2 times a day for 28 days. Do not use the solution for inhalation by any other route; do not use the solution for inhalation in the eyes or for injection.
Injectable:

The dose your doctor recommends may be based on the following:

• the condition being treated
• how you respond to this medication
• your weight

The recommended adult dose of tobramycin to be injected into a vein or a muscle is 3 mg/kg/day, divided in 3 equal doses administered every 8 hours. The dose should be decreased for poor kidney function, and it may be increased on the basis of infection severity.

If you take too much tobramycin, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If tobramycin is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

Keep this and all medicines out of the reach of children.

Topical:

• Store tobramycin ointments and eye drops at room temperature.

Inhalation:

• Store tobramycin solution for inhalation under refrigeration (36‑46°F/2‑8°C). Do not expose the capsules to intense light.
• Store tobramycin capsules for inhalation at room temperature.

Injectable:

• Store tobramycin for injection at room temperature.

Injectable:

WARNINGS

Patients treated with tobramycin injection and other aminoglycosides should be under close clinical observation, because these drugs have an inherent potential for causing ototoxicity and nephrotoxicity.

Neurotoxicity, manifested as both auditory and vestibular ototoxicity, can occur. The auditory changes are irreversible, are usually bilateral, and may be partial or total. Eighth-nerve impairment and nephrotoxicity may develop, primarily in patients having pre-existing renal damage and in those with normal renal function to whom aminoglycosides are administered for longer periods or in higher doses than those recommended. Other manifestations of neurotoxicity may include numbness, skin tingling, muscle twitching, and convulsions. The risk of aminoglycoside-induced hearing loss increases with the degree of exposure to either high peak or high trough serum concentrations. Patients who develop cochlear damage may not have symptoms during therapy to warn them of eighth-nerve toxicity, and partial or total irreversible bilateral deafness may continue to develop after the drug has been discontinued.

Rarely, nephrotoxicity may not become apparent until the first few days after cessation of therapy. Aminoglycoside-induced nephrotoxicity usually is reversible.

Renal and eighth-nerve function should be closely monitored in patients with known or suspected renal impairment and also in those whose renal function is initially normal but who develop signs of renal dysfunction during therapy. Peak and trough serum concentrations of aminoglycosides should be monitored periodically during therapy to assure adequate levels and to avoid potentially toxic levels. Prolonged serum concentrations above 12 mcg/mL should be avoided. Rising trough levels (above 2 mcg/mL) may indicate tissue accumulation. Such accumulation, excessive peak concentrations, advanced age, and cumulative dose may contribute to ototoxicity and nephrotoxicity. Urine should be examined for decreased specific gravity and increased excretion of protein, cells, and casts. Blood urea nitrogen, serum creatinine, and creatinine clearance should be measured periodically. When feasible, it is recommended that serial audiograms be obtained in patients old enough to be tested, particularly high-risk patients. Evidence of impairment of renal, vestibular, or auditory function requires discontinuation of the drug or dosage adjustment.

Tobramycin injection should be used with caution in premature and neonatal infants because of their renal immaturity and the resulting prolongation of serum half-life of the drug.

Concurrent and sequential use of other neurotoxic and/or nephrotoxic antibiotics, particularly other aminoglycosides (e.g., amikacin, streptomycin, neomycin, kanamycin, gentamicin, and paromomycin), cephaloridine, viomycin, polymyxin B, colistin, cisplatin, and vancomycin, should be avoided. Other factors that may increase patient risk are advanced age and dehydration.

Aminoglycosides should not be given concurrently with potent diuretics, such as ethacrynic acid and furosemide. Some diuretics themselves cause ototoxicity, and intravenously administered diuretics enhance aminoglycoside toxicity by altering antibiotic concentrations in serum and tissue.

Aminoglycosides can cause fetal harm when administered to a pregnant woman.