Gentamicin is a drug to overcome mild to severe bacterial infections in various parts of the body, from the outer ear, eyes, skin, to the brain. It should be noted that this medicine cannot be used to treat infections caused by viruses or fungi.

Gentamicin belongs to the group of aminoglycoside antibiotics . This drug works by disrupting the protein production process needed to build the bacterial cell wall. That way, the bacterial cell wall becomes damaged and the bacteria will die.

Gentamicin trademarks: Sagestam, Diprogenta, Genta, Gragenta, Licogenta, Gentamicin Sulfate, Cordema-G, Salgen Plus, Salticin, Erladerm-G, B-Mycin, Maxgenta, CVG, Biogen, Gentacortin, Digenta, Inagen, Sonigen, Lantamicin- B, Genmycin, Lantamicin, Flurozen, Mortagen, Genoint

What is Gentamicin

Group Prescription drugs
Category Aminoglycoside antibiotics
Benefits Treats bacterial infections
Used by Adults and children
Gentamicin for pregnant and lactating women Category D: There is positive evidence about the risk to the human fetus, but the magnitude of the benefit obtained may be greater than the risk, for example to overcome a life-threatening situation. The content of gentamicin can be absorbed into breast milk. If you are breastfeeding, do not use this medicine before consulting a doctor.
Drug form Creams, ointments, eye ointments, injections, infusions, eye drops, or ear drops

Warnings Before Using Gentamicin

Gentamicin should be used according to the doctor's prescription. Consider the following before using gentamicin:

  • Tell your doctor about any allergies you have. Gentamicin should not be given to patients who are allergic to this drug, sulfate allergy, or allergic to other aminoglycoside drugs , such as tobramycin or amikacin .
  • Tell your doctor if you suffer from asthma, kidney disease , open wounds in the area to be treated, myasthenia gravis , ruptured eardrums, Parkinson's disease , frequent dehydration, or electrolyte disorders , such as lack of calcium, magnesium, or potassium.
  • Tell your doctor if you are undergoing treatment with supplements, herbal products, or other drugs.
  • Tell your doctor if you are pregnant, breastfeeding, or planning to become pregnant. Use effective contraception during treatment with gentamicin to avoid pregnancy.
  • Tell the doctor that you are undergoing treatment with gentamicin if you plan to have surgery.
  • Tell your doctor immediately if you experience a drug allergic reaction , more serious side effects, or an overdose after using gentamicin.

Dosage and Administration of Gentamicin

The dose of gentamicin will be adjusted to the condition suffered, age, and weight of the patient, as well as the form of the drug. Here is a general dose of gentamicin:

Condition: Skin infection

Drug form: Cream or ointment 0.1%

  • Adults and children: Apply enough cream or ointment on the problem area, 3-4 times a day.

Condition: Eye infection

Drug form: 0.3% eye drops

  • Adults and children: 1–2 drops in the affected eye, every 4 hours.

Condition: Severe eye infection

Drug form: 0.3% eye drops

  • Adults and children: Initial dose 1–2 drops in the affected eye, every 15–20 minutes. The frequency of drug use will be gradually reduced after the infection is controlled.

Drug form: Eye ointment 0.3%

  • Adults and children: About 1 cm of ointment is given to the problem eye, 2–3 times a day.

Condition: Otitis externa

Pharmaceutical form: Ear drops 0.3%

  • Adults and children: 2–3 drops in the affected ear, 3–4 times a day.

Conditions: Known bacterial infections can be killed with gentamicin

Drug form: Injection into a blood vessel (intravenous/IV), injection into a muscle (intramuscular/IM), or IV infusion

  • Adults
    • Dose for severe infections 3–5 mg/kgBW per day divided in 3 doses given every 8 hours, for 7–10 days. The dose is given by IM or IV injection over 2-3 minutes or infusion over 20-30 minutes.
    • An alternative dose for severe infections is 5−7 mg/kgBW, 1 time per day, given by infusion. Advanced doses are given based on the level of gentamicin in the blood.
  • Children
    • Age <1 month: 4–7 mg/kgBB per day, given in 1–2 doses.
    • Age ≥1 month: 4.5–7.5 mg/kgBB per day, given in 1–2 doses.
    • Age ≥1 year: 3–6 mg/kgBB per day, given in 1–2 doses.

Condition: Bacterial meningitis or inflammation of the ventricles of the brain (ventriculitis)

Drug form: Liquid for injection

  • Adults: 1 mg/kgBW per day by injection into the spinal canal (intrathecal) or into the brain (intraventricular), followed by a dose of 1 mg/kgBW every 8 hours by IM or IV injection.

How to Use Gentamicin Correctly

Gentamicin injection will be given by a doctor or medical staff under the supervision of a doctor in the hospital. This drug can be given by injection into muscles, blood vessels, spinal canal, or the subarachnoid space and ventricles of the brain, also through infusion into blood vessels.

Consume more water during treatment with gentamicin injection or infusion. This is done to reduce the risk of kidney damage

Gentamicin in the form of cream, ointment, eye ointment, eye drops, or ear drops should be used according to the doctor's prescription. Be sure to read the medicine package before using it. Wash your hands before and after using the medicine.

Do not use medicine inside the mouth and nose. Immediately rinse with water until clean if the medicine touches the area.

Gentamicin in the form of cream and ointment should be applied evenly and thinly on the problem skin area. Previously, the skin area should be cleaned and dried first. If allowed by the doctor, you can cover the treated area with a sterile bandage.

Gentamicin in the form of eye drops is used by instilling the medicine into the lower eyelid which is pulled forward to form a pocket. Close your eyes and gently press the corner of your eye near your nose with your finger for 1-2 minutes before opening your eyes again.

Gentamicin in the form of eye ointment is also inserted into the lower eyelid which has been pulled to form a bag. Close your eyes for 1-2 minutes to ensure the medicine is well absorbed. If using eye drops and ointment at the same time, make sure to use the eye drops first.

Gentamicin in the form of ear drops should be dripped into the ear when you are lying on your side or tilting your head. Make sure to stay in that position until 10 minutes have passed after using the medicine.

If you need to use other eye drops, eye ointment, or ear drops on the same area, allow a 5-minute break between medications.

Use gentamicin at the same time every day for effective treatment. Before you complete the treatment time given by the doctor, do not stop using the medicine even if the condition you are suffering from has improved. This is important to prevent bacterial resistance to gentamicin.

If you forget to use gentamicin on time, use it immediately when the interval with the next dose is not too close. When it is close, ignore the dose and do not double the next dose.

During treatment with gentamicin, you may need to undergo routine examinations, such as blood tests, urine tests, and ear, nerve, or kidney function tests, to ensure that the treatment is working well and that no side effects occur.

Store the medicine in a closed container in a cool and dry place away from direct sunlight. Keep the medicine out of the reach of children.

Interactions of Gentamicin with Other Drugs

There are several drug interactions that can occur if gentamicin is used with certain drugs, among others:

  • Decreased therapeutic effect of neostigmine and pyridostigmine
  • Increased levels in the blood if used with indomethacin in newborns
  • Increased risk of blood calcium deficiency (hypocalcemia) if used with bisphosphonates
  • Increased risk of bleeding if used with oral anticoagulants
  • Increased risk of side effects of nerve and kidney damage if used with amphotericin B, cephalosporin , ciclosporin, cisplatin , methicillin, muscle relaxants, such as succinylcholine, botulinum toxin ( botox ), or tubocurarine, as well as strong diuretics , such as ethacrynic acid or furosemide

Side Effects and Dangers of Gentamicin

Side effects after the use of gentamicin can vary, depending on the form of the drug and the patient's response to treatment. Some of the side effects that can occur after the use of gentamicin are:

  • Itching, redness, or irritation on the skin where the medicine is applied
  • Ear irritation and a stinging or burning sensation in the treated ear
  • Redness of the eye, inner lining of the eye, or eyelid
  • Pain in the injected area
  • Joint pain
  • Headache
  • Mood swings
  • Visual impairment
  • Nausea , vomiting, loss of appetite, or weight loss
  • Feeling like you're going to faint

Contact a doctor if the above side effects worsen or do not improve immediately. See a doctor immediately if there is an allergic reaction to the drug or serious side effects that can occur after injecting this drug, such as:

  • Hearing loss or ringing in the ears
  • Breathing becomes short and weak
  • Tingling or numbness
  • Muscles twitch or tense
  • Severe abdominal pain, diarrhea, or bloody stools
  • Fever, oral thrush , swollen and reddish gums, and difficulty swallowing
  • Convulsions
  • Kidney disorders characterized by difficulty urinating, reduced urine volume, fatigue, shortness of breath, or swelling in the legs
  • Electrolyte disturbances marked by confusion, weakness, bone pain, or more frequent urination
  • Increased pressure in the bones of the skull marked by ringing in the ears ( tinnitus ), dizziness, nausea, visual disturbances, or pain behind the eyes
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