Gentamicin
Gentamicin is used to treat bacterial infections. Gentamicin can cause kidney damage and hearing loss. Patients should be closely monitored while receiving gentamicin.
Gentamicin Overview
Gentamicin 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. Gentamicin can be used topically to treat eye and skin infections.
Gentamicin 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, gentamicin solution is usually used every 4 to 8 hours and the ointment is applied 2 to 4 times a day.
Gentamicin is also available as a cream and an ointment for topical application to the skin. It is applied to skin lesions or infections 3 to 4 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 gentamicin include upset stomach, decreased appetite, pain at the injection site, fever, and tiredness.
Gentamicin can also cause dizziness. Do not drive or operate heavy machinery until you know how gentamicin affects you.
How was your experience with Gentamicin?
Gentamicin Cautionary Labels
Uses of Gentamicin
Topical:
Gentamicin is a prescription medication used to treat infections of the skin and eyes that care caused by bacteria.
Injectable:
Gentamicin 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.
Gentamicin Brand Names
Gentamicin may be found in some form under the following brand names:
Gentamicin Drug Class
Gentamicin is part of the drug class:
Side Effects of Gentamicin
Serious side effects have been reported with gentamicin. See the “Gentamicin Precautions” section.
Topical:
Common side effects of gentamicin for the skin include itching and redness at the site of application.
Common side effects of gentamicin for the eyes include burning and irritation of the eye.
Injectable:
Common side effects of injectable gentamicin include:
- nausea
- vomiting
- diarrhea
- decreased appetite
- pain at the injection site
- headache
- fever
- joint pain
- unusual tiredness
This is not a complete list of gentamicin 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.
Gentamicin Interactions
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 gentamicin drug interactions. Ask your doctor or pharmacist for more information.
Gentamicin Precautions
Topical:
Serious side effects have been reported with topical gentamicin including burning or itching at the application site.
Injectable:
Serious side effects have been reported with injectable gentamicin 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
Gentamicin 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
- visual disturbances
- decreased appetite
- weight loss
- changes in blood pressure
- rash
- itching
- hives
- peeling or blistering of the skin
- generalized burning sensation
- fever
- headache
- nausea
- vomiting
- increased salivation
- inflammation of the mouth and lips
- hair loss
- joint pain
- swelling of the eyes, face, throat, tongue, or lips
- difficulty breathing or swallowing
- hoarseness
Gentamicin can cause dizziness. Do not drive or operate heavy machinery until you know how gentamicin affects you.
Do not take gentamicin if you are allergic to gentamicin or to any of its ingredients.
Gentamicin Food Interactions
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 gentamicin, there are no specific foods that you must exclude from your diet when receiving this medication.
Inform MD
Before taking gentamicin, tell your doctor about all of your medical conditions. Especially tell your doctor if you:
- are allergic to gentamicin or to any of its ingredients
- are allergic to other aminoglycoside antibiotics such as amikacin, kanamycin, neomycin, paromomycin, streptomycin, or tobramycin
- are allergic to sulfites
- 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.
Gentamicin and Pregnancy
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.
Gentamicin for injection falls into category D. It has been shown that use of gentamicin 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 gentamicin falls into category C. There are no adequate and well-controlled studies in pregnant women. Gentamicin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Gentamicin and Lactation
Tell your doctor if you are breastfeeding or plan to breastfeed.
After maternal injection, gentamicin has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from gentamicin, 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 a topical formulation for the eyes or skin that contains gentamicin presents little or no risk for the nursing infant.
Gentamicin Usage
Take gentamicin 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, gentamicin solution is usually used every 4 to 8 hours and the ointment is applied 2 to 4 times a day.
Gentamicin is also available as a cream and an ointment for topical application to the skin. It is applied to skin lesions or infections 3 to 4 times a day.
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 two doses of gentamicin at the same time.
Injectable:
Gentamicin is also available in an injectable form to be given directly into a vein (IV) or a muscle (IM) by a healthcare professional.
Gentamicin Dosage
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 skin infections, a small amount of gentamicin cream or ointment should be applied gently to lesions 3 or 4 times daily. The area treated may be covered with a gauze dressing if desired.
For eye infections, the recommended dose of gentamicin 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.
The ointment for use in the eyes should not be used on the skin.
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 gentamicin 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.
Gentamicin Overdose
If you take too much gentamicin, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.
If gentamicin 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.
Forms of Medication
Other Requirements
Topical:
Store gentamicin creams, ointments, and eye drops at room temperature.
Injectable:
Store gentamicin for injection in the freezer or refrigerator.
Keep this and all medicines out of the reach of children.
Gentamicin FDA Warning
Injectable:
BOXED WARNINGS
Patients treated with aminoglycosides should be under close clinical observation because of the potential toxicity associated with their use.
As with other aminoglycosides, gentamicin injection is potentially nephrotoxic. The risk of nephrotoxicity is greater in patients with impaired renal function and in those who receive high dosage of prolonged therapy.
Neurotoxicity manifested by ototoxicity, both vestibular and auditory, can occur in patients treated with gentamicin, primarily in those with pre-existing renal damage and in patients with normal renal function treated with higher doses and/or for longer periods than recommended. Aminoglycoside-induced ototoxicity is usually irreversible. Other manifestations of neurotoxicity may include numbness, skin tingling, muscle twitching and convulsions.
Renal and eighth cranial nerve function should be closely monitored, especially in patients with known or suspected reduced renal function at onset of therapy and also in those whose renal function is initially normal but who develop signs of renal dysfunction during therapy. Urine should be examined for decreased specific gravity, increased excretion of protein and the presence of cells or casts. Blood urea nitrogen (BUN), serum creatinine or creatinine clearance should be determined periodically. When feasible, it is recommended that serial audiograms be obtained in patients old enough to be tested, particularly high-risk patients. Evidence of ototoxicity (dizziness, vertigo, tinnitus, roaring in the ears or hearing loss) or nephrotoxicity requires dosage adjustment or discontinuance of the drug. As with the other aminoglycosides, on rare occasions changes in renal and eighth cranial nerve function may not become manifest until soon after completion of therapy.
Serum concentrations of aminoglycosides should be monitored when feasible to assure adequate levels and to avoid potentially toxic levels. When monitoring gentamicin peak concentrations, dosage should be adjusted so that prolonged levels above 12 mcg/mL are avoided. When monitoring gentamicin trough concentrations, dosage should be adjusted so that levels above 2 mcg/mL are avoided. Excessive peak and/or trough serum concentrations of aminoglycosides may increase the risk of renal and eighth cranial nerve toxicity.
In the event of overdosage or toxic reactions, hemodialysis may aid in the removal of gentamicin from the blood, especially if renal function is, or becomes, compromised. The rate of removal of gentamicin is considerably lower by peritoneal dialysis than it is by hemodialysis.
In the newborn infant, exchange transfusions may also be considered.
Concurrent and/or sequential systemic or topical use of other potentially neurotoxic and/or nephrotoxic drugs, such as cisplatin, cephaloridine, kanamycin, amikacin, neomycin, polymyxin B, colistin, paromomycin, streptomycin, tobramycin, vancomycin and viomycin, should be avoided. Other factors which may increase patient risk of toxicity are advanced age and dehydration.
The concurrent use of gentamicin with potent diuretics, such as ethacrynic acid or furosemide, should be avoided, since certain diuretics by themselves may cause ototoxicity. In addition, when administered intravenously, diuretics may enhance aminoglycoside toxicity by altering the antibiotic concentration in serum and tissue.
Aminoglycosides can cause fetal harm when administered to a pregnant woman.
