Gentamicin 80mg/ml Inj, 2ml
WARNING: This drug may cause kidney, nerve, and hearing problems (like long-lasting hearing loss), even at normal doses. The risk may be higher if you already have kidney or hearing problems, you take higher doses, or you use this drug for a long time. The risk may be higher in older people, infants, or with dehydration. Hearing loss can happen even after this drug is stopped. If you already have kidney problems or hearing problems, tell your doctor. You may need to have hearing and kidney tests.Do not use this drug if you are taking or have recently taken any drugs that can cause nerve, kidney, or hearing problems. This may be drugs like amphotericin B, bacitracin, cephaloridine, cisplatin, colistin, cyclosporine, ethacrynic acid, furosemide, paromomycin, polymyxin B, vancomycin, viomycin, or other drugs like this one. There are many other drugs that can do this. Ask your doctor or pharmacist if you are not sure.Muscle problems (muscle weakness) and severe breathing problems have happened with drugs like this one. The risk is higher in people who already have nerve or muscle problems like myasthenia gravis. The risk is also higher in people who are getting other drugs like those that are used to put you to sleep or to relax muscles. If you have questions, talk with the doctor.This drug may cause harm to the unborn baby if you take it while you are pregnant. If you are pregnant or you get pregnant while taking this drug, call your doctor right away. @ COMMON USES: It is used to treat bacterial infections.
Drug Class
Antibiotic
Pharmacologic Class
Aminoglycoside
Pregnancy Category
Category D
FDA Approved
Jun 1966
DEA Schedule
Not Controlled
Overview
What is this medicine?
Gentamicin is an antibiotic used to treat serious bacterial infections, especially those caused by certain types of bacteria that are resistant to other drugs. It works by stopping the growth of bacteria. It is given as an injection, either into a vein (IV) or a muscle (IM).
How to Use This Medicine
To use this medication correctly, follow your doctor's instructions and read all accompanying information carefully. This medication is administered either as an injection into a muscle or as an intravenous infusion over a specified period. Unless your doctor advises you to limit fluid intake, be sure to drink plenty of non-caffeinated liquids.
For storage and disposal, consult with your doctor, nurse, or pharmacist for guidance on how to properly store this medication at home, if necessary.
If you miss a dose, contact your doctor promptly to determine the best course of action.
For storage and disposal, consult with your doctor, nurse, or pharmacist for guidance on how to properly store this medication at home, if necessary.
If you miss a dose, contact your doctor promptly to determine the best course of action.
Lifestyle & Tips
- Stay well-hydrated unless otherwise instructed by your doctor.
- Report any changes in hearing (ringing in ears, dizziness, feeling off balance) or changes in urination (less urine, swelling) immediately.
- Avoid taking other medications that can harm your kidneys or ears without consulting your doctor.
Available Forms & Alternatives
Available Strengths:
- Gentamicin 0.3% Ophth Soln 5ml
- Gentamicin 0.3% Ophth Solution
- Gentamicin 40mg/ml Inj, 2ml
- Gentamicin 0.1% Cream 15gm
- Gentamicin 40mg/ml Inj, 20ml
- Gentamicin 0.1% Cream 30gm
- Gentamicin Pf Ped 10mg/ml Inj, 2ml
- Gentamicin 0.1% Oint 15gm (topical)
- Gentamicin 0.1% Oint 30gm (topical)
- Gentamicin 80mg/ml Inj, 2ml
Dosing & Administration
Adult Dosing
Standard Dose:
Conventional dosing: 3-5 mg/kg/day IV/IM in 3 divided doses (q8h). Extended-interval dosing: 5-7 mg/kg IV/IM once daily.
Dose Range:
3 - 7 mg
Condition-Specific Dosing:
seriousInfections:
5 mg/kg/day in 3 divided doses or 5-7 mg/kg once daily.
urinaryTractInfections:
3 mg/kg/day in 3 divided doses or 5 mg/kg once daily.
Pediatric Dosing
Neonatal:
Premature or full-term <1 week: 2.5 mg/kg/dose IV/IM q12-24h. Full-term 1 week to 1 month: 2.5 mg/kg/dose IV/IM q8-12h.
Infant:
1 month to <1 year: 2.5 mg/kg/dose IV/IM q8h.
Child:
1 year to 12 years: 2-2.5 mg/kg/dose IV/IM q8h.
Adolescent:
12 years and older: Same as adult dosing (2-2.5 mg/kg/dose IV/IM q8h or 5-7 mg/kg once daily).
Dose Adjustments
Renal Impairment:
Mild:
Adjust dose or extend interval based on creatinine clearance (CrCl). CrCl 60-90 mL/min: Administer 60-90% of dose or extend interval to 8-12 hours.
Moderate:
CrCl 30-59 mL/min: Administer 30-50% of dose or extend interval to 12-24 hours.
Severe:
CrCl <30 mL/min: Administer 20-30% of dose or extend interval to 24-48 hours.
Dialysis:
Hemodialysis: Administer 1-1.7 mg/kg post-dialysis. Peritoneal Dialysis: 0.5-1 mg/kg every 24-48 hours or 4-8 mg/L in dialysate.
Hepatic Impairment:
Mild:
No specific adjustment recommended.
Moderate:
No specific adjustment recommended.
Severe:
No specific adjustment recommended. Monitor renal function closely as hepatic impairment can indirectly affect renal perfusion.
Pharmacology
Mechanism of Action
Gentamicin is an aminoglycoside antibiotic that irreversibly binds to the bacterial 30S ribosomal subunit, leading to misreading of mRNA and inhibition of protein synthesis. This results in the production of non-functional proteins and ultimately bacterial cell death.
Pharmacokinetics
Absorption:
Bioavailability:
Poor (oral), ~100% (IM/IV)
Tmax:
0.5-1 hour (IM), End of infusion (IV)
FoodEffect:
Not applicable (parenteral administration)
Distribution:
Vd:
0.2-0.3 L/kg (increases in ascites, edema; decreases in dehydration)
ProteinBinding:
<30%
CnssPenetration:
Limited (increases with inflamed meninges)
Elimination:
HalfLife:
2-4 hours (normal renal function), significantly prolonged in renal impairment
Clearance:
Directly proportional to creatinine clearance
ExcretionRoute:
Renal (glomerular filtration)
Unchanged:
>90%
Pharmacodynamics
OnsetOfAction:
Rapid (within minutes of IV infusion)
PeakEffect:
Within 30-60 minutes post-infusion (IV), 30-90 minutes post-IM injection
DurationOfAction:
Concentration-dependent killing with post-antibiotic effect (PAE) allowing for extended-interval dosing.
Safety & Warnings
BLACK BOX WARNING
NEPHROTOXICITY: Aminoglycosides can cause irreversible nephrotoxicity. The risk is greater in patients with impaired renal function, those receiving high doses or prolonged therapy, the elderly, and those receiving concomitant nephrotoxic drugs. OTOTOXICITY: Aminoglycosides can cause irreversible ototoxicity (vestibular and cochlear). The risk is greater in patients with impaired renal function, those receiving high doses or prolonged therapy, the elderly, and those receiving concomitant ototoxic drugs. NEUROMUSCULAR BLOCKADE: Aminoglycosides can cause neuromuscular blockade and respiratory paralysis, especially when administered rapidly or to patients with neuromuscular disorders (e.g., myasthenia gravis).
Side Effects
Serious Side Effects: Seek Medical Help Immediately
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of kidney problems, including:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Signs of high or low blood pressure, such as:
+ Severe headache or dizziness
+ Fainting or loss of consciousness
+ Changes in vision
Dizziness or fainting
Balance problems
Ringing in the ears, hearing loss, or other changes in hearing
Muscle weakness
New or worsening breathing difficulties
Abnormal burning, numbness, or tingling sensations
Twitching
Seizures
Confusion
Extreme fatigue or weakness
Depression
Changes in vision
Fever
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Decreased appetite
Weight loss
Headache
Upset stomach or vomiting
Excessive saliva production
Mouth irritation or mouth sores
Hair loss
Joint pain
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of kidney problems, including:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Signs of high or low blood pressure, such as:
+ Severe headache or dizziness
+ Fainting or loss of consciousness
+ Changes in vision
Dizziness or fainting
Balance problems
Ringing in the ears, hearing loss, or other changes in hearing
Muscle weakness
New or worsening breathing difficulties
Abnormal burning, numbness, or tingling sensations
Twitching
Seizures
Confusion
Extreme fatigue or weakness
Depression
Changes in vision
Fever
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Decreased appetite
Weight loss
Headache
Upset stomach or vomiting
Excessive saliva production
Mouth irritation or mouth sores
Hair loss
Joint pain
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Ringing in the ears (tinnitus)
- Hearing loss
- Dizziness or vertigo
- Difficulty with balance or walking
- Numbness or tingling
- Muscle weakness
- Decreased urine output
- Swelling in the ankles or feet
- Difficulty breathing
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about any allergies you have, including:
Allergies to this medication or any of its components
Allergies to other medications, foods, or substances
The specific symptoms you experienced as a result of the allergy
Additionally, this medication may interact with other medications or health conditions. To ensure safe use, please discuss the following with your doctor and pharmacist:
All medications you are currently taking, including prescription and over-the-counter medications, natural products, and vitamins
* Any existing health problems or conditions
It is crucial to verify that it is safe to take this medication with all your other medications and health conditions. Do not start, stop, or change the dose of any medication without first consulting your doctor.
It is essential to inform your doctor about any allergies you have, including:
Allergies to this medication or any of its components
Allergies to other medications, foods, or substances
The specific symptoms you experienced as a result of the allergy
Additionally, this medication may interact with other medications or health conditions. To ensure safe use, please discuss the following with your doctor and pharmacist:
All medications you are currently taking, including prescription and over-the-counter medications, natural products, and vitamins
* Any existing health problems or conditions
It is crucial to verify that it is safe to take this medication with all your other medications and health conditions. Do not start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you have a known allergy to sulfites, consult your doctor, as some formulations of this drug may contain sulfites.
Regular monitoring of your blood work, hearing, and other laboratory tests is crucial, as directed by your doctor. Do not exceed the prescribed duration of treatment, as this may increase the risk of a secondary infection.
If you are 65 years or older, exercise caution when using this medication, as you may be more susceptible to side effects. Additionally, if you are breastfeeding, consult your doctor to discuss potential risks to your baby and determine the best course of action.
Regular monitoring of your blood work, hearing, and other laboratory tests is crucial, as directed by your doctor. Do not exceed the prescribed duration of treatment, as this may increase the risk of a secondary infection.
If you are 65 years or older, exercise caution when using this medication, as you may be more susceptible to side effects. Additionally, if you are breastfeeding, consult your doctor to discuss potential risks to your baby and determine the best course of action.
Overdose Information
Overdose Symptoms:
- Severe kidney damage (decreased urine, swelling)
- Severe hearing loss or deafness
- Severe dizziness or vertigo
- Muscle weakness, difficulty breathing, or respiratory arrest
- Neuromuscular blockade
What to Do:
Call 911 or your local emergency number immediately. For advice, call a poison control center at 1-800-222-1222. Treatment may involve hemodialysis to remove the drug from the body, and supportive care for respiratory depression (e.g., mechanical ventilation, calcium salts, anticholinesterases).
Drug Interactions
Major Interactions
- Nephrotoxic drugs (e.g., amphotericin B, cisplatin, cyclosporine, NSAIDs, loop diuretics, vancomycin, tacrolimus): Increased risk of nephrotoxicity.
- Ototoxic drugs (e.g., loop diuretics, vancomycin, cisplatin, ethacrynic acid): Increased risk of ototoxicity.
- Neuromuscular blocking agents (e.g., succinylcholine, rocuronium, vecuronium): Potentiation of neuromuscular blockade, leading to respiratory depression/paralysis.
Moderate Interactions
- Cephalosporins (e.g., cephalothin): Possible increased risk of nephrotoxicity (controversial).
- Oral anticoagulants (e.g., warfarin): Potential for increased anticoagulant effect due to vitamin K synthesis inhibition by gut flora (rare).
- Mycophenolate mofetil: Reduced mycophenolate levels due to disruption of enterohepatic recirculation.
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Renal function (Serum Creatinine, BUN, CrCl)
Rationale: Gentamicin is primarily renally eliminated and is nephrotoxic. Baseline function is crucial for dosing and monitoring for toxicity.
Timing: Prior to first dose.
Audiometry/Vestibular function
Rationale: Baseline assessment for ototoxicity, especially in patients at higher risk or prolonged therapy.
Timing: Prior to first dose, if feasible and clinically indicated.
Electrolytes (Potassium, Magnesium, Calcium)
Rationale: Aminoglycosides can cause electrolyte disturbances, particularly hypomagnesemia.
Timing: Prior to first dose.
Routine Monitoring
Serum Gentamicin levels (Peak and Trough)
Frequency: After 3rd-4th dose (conventional dosing) or 1st-2nd dose (extended-interval dosing), then every 3-7 days or as clinically indicated.
Target: Conventional: Peak 4-10 mcg/mL, Trough <2 mcg/mL. Extended-interval: Trough <1 mcg/mL (or undetectable).
Action Threshold: Trough levels >2 mcg/mL (conventional) or >1 mcg/mL (extended-interval) indicate accumulation and increased risk of toxicity; adjust dose/interval. Subtherapeutic peak levels may indicate inadequate dosing.
Renal function (Serum Creatinine, BUN)
Frequency: Daily or every 1-3 days, depending on patient stability and duration of therapy.
Target: Stable or improving from baseline.
Action Threshold: Increase in serum creatinine by >0.5 mg/dL or >25% from baseline, or oliguria, indicates potential nephrotoxicity; consider dose adjustment or discontinuation.
Urine output
Frequency: Daily
Target: >0.5 mL/kg/hr
Action Threshold: Decreased urine output may indicate renal impairment.
Electrolytes (Magnesium, Potassium)
Frequency: Every 3-7 days or as clinically indicated.
Target: Within normal limits.
Action Threshold: Hypomagnesemia or hypokalemia; supplement as needed.
Symptom Monitoring
- Hearing loss (tinnitus, high-frequency hearing loss)
- Vertigo, dizziness, nystagmus, ataxia (vestibular toxicity)
- Nausea, vomiting
- Muscle weakness, respiratory depression (neuromuscular blockade)
- Decreased urine output, edema (nephrotoxicity)
Special Patient Groups
Pregnancy
Gentamicin is classified as Pregnancy Category D. It can cause fetal harm when administered to a pregnant woman. Aminoglycosides cross the placenta and have been associated with total, irreversible, bilateral congenital deafness in children whose mothers received streptomycin during pregnancy. While not definitively linked to gentamicin, the risk of ototoxicity cannot be excluded.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm, including ototoxicity. Use only if potential benefit justifies the potential risk to the fetus.
Second Trimester:
Continued risk of fetal ototoxicity and nephrotoxicity.
Third Trimester:
Continued risk of fetal ototoxicity and nephrotoxicity. May also cause neuromuscular blockade in the neonate if administered close to delivery.
Lactation
Gentamicin is excreted into breast milk in small amounts. While systemic absorption by the infant is poor, there is a theoretical risk of altering infant gut flora, direct effects on the infant, or masking of infection. The American Academy of Pediatrics considers aminoglycosides compatible with breastfeeding. Monitor infant for diarrhea, candidiasis, or rash. Use with caution, especially in premature infants or those with impaired renal function.
Infant Risk:
L3 (Moderately Safe)
Pediatric Use
Dosing must be carefully calculated based on weight and age, with close monitoring of serum levels and renal function due to varying pharmacokinetics in different pediatric age groups, especially neonates and infants. Higher risk of toxicity in neonates due to immature renal function.
Geriatric Use
Elderly patients are at increased risk for nephrotoxicity and ototoxicity due to age-related decline in renal function and pre-existing hearing impairment. Dosing should be carefully adjusted based on estimated creatinine clearance, and close monitoring of renal function and serum drug levels is essential. Extended-interval dosing may be preferred if appropriate.
Clinical Information
Clinical Pearls
- Always obtain baseline renal function and monitor closely throughout therapy due to significant nephrotoxicity risk.
- Therapeutic drug monitoring (TDM) with peak and trough levels is crucial for optimizing efficacy and minimizing toxicity, especially with conventional dosing.
- Extended-interval (once-daily) dosing is often preferred for most indications due to reduced nephrotoxicity and comparable efficacy, but requires careful patient selection and monitoring.
- Ensure adequate hydration to minimize nephrotoxicity.
- Counsel patients on symptoms of ototoxicity (hearing changes, dizziness) and nephrotoxicity (decreased urine output, swelling) and to report them immediately.
- Avoid concomitant use with other nephrotoxic or ototoxic drugs whenever possible.
Alternative Therapies
- Other aminoglycosides (e.g., tobramycin, amikacin, streptomycin)
- Carbapenems (e.g., meropenem, imipenem/cilastatin, doripenem, ertapenem)
- Polymyxins (e.g., colistin, polymyxin B) for multi-drug resistant Gram-negative infections
- Newer beta-lactam/beta-lactamase inhibitor combinations (e.g., ceftazidime/avibactam, meropenem/vaborbactam)
- Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) for susceptible Gram-negative infections
Cost & Coverage
Average Cost:
Varies widely per 2ml vial
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic)
General Drug Facts
If your symptoms or health problems do not improve or worsen over time, it is essential to contact your doctor for further guidance. To ensure your safety and the safety of others, never share your medication with anyone, and do not take medication prescribed to someone else.
Store all medications in a secure location, out of the reach of children and pets, to prevent accidental ingestion. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless specifically instructed to do so by your pharmacist or healthcare provider. Instead, consult with your pharmacist to determine the best disposal method, as some communities have drug take-back programs in place.
Some medications may come with an additional patient information leaflet; check with your pharmacist to see if this applies to your prescription. If you have any questions or concerns about your medication, do not hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider for guidance.
In the event of a suspected overdose, immediately contact your local poison control center or seek emergency medical attention. Be prepared to provide critical information, including the name of the medication, the amount taken, and the time it was ingested, to ensure prompt and effective treatment.
Store all medications in a secure location, out of the reach of children and pets, to prevent accidental ingestion. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless specifically instructed to do so by your pharmacist or healthcare provider. Instead, consult with your pharmacist to determine the best disposal method, as some communities have drug take-back programs in place.
Some medications may come with an additional patient information leaflet; check with your pharmacist to see if this applies to your prescription. If you have any questions or concerns about your medication, do not hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider for guidance.
In the event of a suspected overdose, immediately contact your local poison control center or seek emergency medical attention. Be prepared to provide critical information, including the name of the medication, the amount taken, and the time it was ingested, to ensure prompt and effective treatment.