Generic Name: gentamicin (jen-ta-MYE-sin)
Medically reviewed by Drugs.com. Last updated on March 8, 2021.
Commonly used brand name(s)
In the U.S.
- Genoptic S.O.P.
Available Dosage Forms:
Therapeutic Class: Antibiotic
Chemical Class: Aminoglycoside
Uses for gentamicin
Gentamicin belongs to the family of medicines called antibiotics. Gentamicin ophthalmic preparations are used to treat infections of the eye.
Gentamicin is available only with your doctor's prescription.
Before using gentamicin
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For gentamicin, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to gentamicin or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
There is no specific information comparing use of gentamicin in babies up to one month of age with use in other age groups.
Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of gentamicin in the elderly with use in other age groups.
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking gentamicin, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using gentamicin with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using gentamicin with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Agalsidase Alfa
- Cholera Vaccine, Live
- Colistimethate Sodium
- Ethacrynic Acid
Using gentamicin with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Proper use of gentamicin
For patients using the eye drop form of gentamicin:
- The bottle is only partially full to provide proper drop control.
- To use:
- First, wash your hands. Tilt the head back and with the index finger of one hand, press gently on the skin just beneath the lower eyelid and pull the lower eyelid away from the eye to make a space. Drop the medicine into this space. Let go of the eyelid and gently close the eyes. Do not blink. Keep the eyes closed for 1 or 2 minutes, to allow the medicine to come into contact with the infection.
- If you think you did not get the drop of medicine into your eye properly, use another drop.
- Avoid wearing contact lenses during treatment
- To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). Also, keep the container tightly closed.
For patients using the eye ointment form of gentamicin:
- First, wash your hands. Tilt the head back and with the index finger of one hand, press gently on the skin just beneath the lower eyelid and pull the lower eyelid away from the eye to make a space. Squeeze a thin strip of ointment into this space. A 1-cm (approximately ⅓-inch) strip of ointment is usually enough unless otherwise directed by your doctor. Let go of the eyelid and gently close the eyes and keep them closed for 1 or 2 minutes, to allow the medicine to come into contact with the infection.
- To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). After using gentamicin eye ointment, wipe the tip of the ointment tube with a clean tissue and keep the tube tightly closed.
To help clear up your infection completely, keep using gentamicin for the full time of treatment, even if your symptoms have disappeared. Do not miss any doses.
The dose of gentamicin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of gentamicin. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For ophthalmic ointment dosage form:
- For eye infections:
- Adults and children—Use every eight to twelve hours.
- For eye infections:
- For ophthalmic solution (eye drops) dosage form:
- For mild to moderate eye infections:
- Adults and children—One to two drops every four hours.
- For severe eye infections:
- Adults and children—One to two drops as often as once every hour as directed by your doctor.
- For mild to moderate eye infections:
If you miss a dose of gentamicin, apply it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Precautions while using gentamicin
If your symptoms do not improve within a few days, or if they become worse, check with your doctor.
Gentamicin side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Itching, redness, swelling, or other sign of irritation not present before use of gentamicin
- redness of eye, eyelid, or inner lining of eyelid
- Black, tarry stools; blood in urine or stools; or unusual bleeding or swelling
- blurred vision, eye pain, sensitivity to light, and/or tearing
- seeing, hearing, or feeling things that are not there
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Burning or stinging
After application, eye ointments usually cause your vision to blur for a few minutes.
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about gentamicin ophthalmic
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Pricing & Coupons
- En Español
- Drug class: ophthalmic anti-infectives
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.