Tobramycin 40mg/ml Inj, 50ml
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
Aug 1975
DEA Schedule
Not Controlled
Overview
What is this medicine?
Tobramycin is an antibiotic given by injection to treat serious bacterial infections, especially those affecting the lungs, blood, or urinary tract. It works by killing the bacteria that cause the infection.
How to Use This Medicine
Taking Your Medication Correctly
To ensure safe and effective use, take this medication exactly as directed by your doctor. Carefully read all the information provided to you and follow the instructions closely. This medication can be administered in two ways: as an injection into a muscle or as an infusion into a vein, which is given over a period of time.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage method.
What to Do If You Miss a Dose
If you miss a dose, contact your doctor immediately to find out the best course of action.
To ensure safe and effective use, take this medication exactly as directed by your doctor. Carefully read all the information provided to you and follow the instructions closely. This medication can be administered in two ways: as an injection into a muscle or as an infusion into a vein, which is given over a period of time.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage method.
What to Do If You Miss a Dose
If you miss a dose, contact your doctor immediately to find out the best course of action.
Lifestyle & Tips
- Stay well-hydrated by drinking plenty of fluids, unless otherwise instructed by your doctor.
- Report any changes in hearing or balance immediately.
- Report any signs of kidney problems, such as decreased urination or swelling.
Available Forms & Alternatives
Available Strengths:
- Tobramycin 0.3% Oph Sol 5ml
- Tobramycin 40mg/ml Injection 25x2ml
- Tobramycin 80mg/2ml Inj Mdv
- Tobramycin Sulf 40mg/ml Inj, 30ml
- Tobramycin 10mg/ml Inj, 2ml
- Tobramycin 300mg/5ml Inh Sol 5ml
- Tobramycin 80mg/2ml Inj, 2ml
- Tobramycin 1.2/30ml Inj, 30ml
- Tobramycin 300mg/5ml Inh Sol 56x5ml
- Tobramycin 300mg/4ml Neb Sol 4ml
- Tobramycin 40mg/ml Inj, 50ml
- Tobramycin 40mg/ml Inj, 2ml
- Tobramycin 1.2gm Inj, 1 Vial
- Tobramycin 1.2gm Inj 1 Vial
Dosing & Administration
Adult Dosing
Standard Dose:
Traditional dosing: 1-1.7 mg/kg IV/IM every 8 hours. Once-daily dosing: 4-7 mg/kg IV/IM once daily.
Dose Range:
1 - 7 mg
Condition-Specific Dosing:
Cystic Fibrosis:
10 mg/kg/day IV once daily or 3.3 mg/kg IV every 8 hours (higher doses often used due to increased clearance).
Urinary Tract Infections (uncomplicated):
Lower doses may be effective, e.g., 3 mg/kg/day once daily.
Pediatric Dosing
Neonatal:
Premature or full-term <1 week: 4 mg/kg/dose IV/IM every 24 hours. Full-term 1 week to 4 weeks: 4 mg/kg/dose IV/IM every 12-24 hours (adjust based on post-natal age and renal function).
Infant:
1 month to <1 year: 2.5 mg/kg/dose IV/IM every 8 hours or 5-7 mg/kg/dose IV/IM once daily.
Child:
1 year to 12 years: 2.5 mg/kg/dose IV/IM every 8 hours or 5-7 mg/kg/dose IV/IM once daily.
Adolescent:
12 years to 18 years: 2.5 mg/kg/dose IV/IM every 8 hours or 5-7 mg/kg/dose IV/IM once daily.
Dose Adjustments
Renal Impairment:
Mild:
CrCl 60-90 mL/min: Extend dosing interval or reduce dose. E.g., 1.7 mg/kg every 12 hours or 4 mg/kg once daily.
Moderate:
CrCl 30-59 mL/min: Extend dosing interval or reduce dose. E.g., 1.7 mg/kg every 24 hours or 2-3 mg/kg once daily.
Severe:
CrCl <30 mL/min: Significantly reduce dose and/or extend interval. E.g., 1.7 mg/kg every 48-72 hours or 1-2 mg/kg once daily. Requires therapeutic drug monitoring (TDM).
Dialysis:
Hemodialysis: Administer dose after dialysis session. Peritoneal Dialysis: Dose adjustment required, often 0.625 mg/kg every 24 hours or 1.25 mg/kg every 48 hours, or add to dialysate. Requires TDM.
Hepatic Impairment:
Mild:
No specific adjustment recommended.
Moderate:
No specific adjustment recommended.
Severe:
No specific adjustment recommended. Tobramycin is primarily renally eliminated.
Pharmacology
Mechanism of Action
Tobramycin is an aminoglycoside antibiotic that binds irreversibly to the 30S ribosomal subunit of susceptible bacteria, inhibiting bacterial protein synthesis. This leads to misreading of mRNA, premature termination of protein synthesis, and insertion of incorrect amino acids, ultimately resulting in a defective bacterial cell membrane and cell death. It exhibits concentration-dependent killing and a significant post-antibiotic effect.
Pharmacokinetics
Absorption:
Bioavailability:
Poor (<1%) orally; nearly 100% after IM/IV administration.
Tmax:
IM: 30-90 minutes; IV: End of infusion (typically 30 minutes).
FoodEffect:
Not applicable (parenteral administration).
Distribution:
Vd:
0.2-0.3 L/kg (increases in edematous states, decreases in dehydration). Primarily distributes into extracellular fluid.
ProteinBinding:
Low (0-10%).
CnssPenetration:
Limited (poor penetration into CSF, even with inflamed meninges).
Elimination:
HalfLife:
2-3 hours (normal renal function); significantly prolonged in renal impairment (up to 24-72 hours).
Clearance:
Approximately 0.08-0.12 L/hr/kg (primarily renal glomerular filtration).
ExcretionRoute:
Renal (glomerular filtration).
Unchanged:
>90%.
Pharmacodynamics
OnsetOfAction:
Rapid (within minutes of IV administration).
PeakEffect:
Within 30-90 minutes post-infusion (for peak levels). Clinical effect depends on infection type and severity.
DurationOfAction:
Post-antibiotic effect allows for once-daily dosing despite short half-life.
Safety & Warnings
BLACK BOX WARNING
Aminoglycosides can cause irreversible ototoxicity (auditory and vestibular) and nephrotoxicity. The risk is greater with prolonged use, higher doses, pre-existing renal impairment, and in the elderly. Neuromuscular blockade and respiratory paralysis have been reported, especially after rapid IV administration or in patients with neuromuscular disorders. Concurrent use with other neurotoxic or nephrotoxic drugs should be avoided.
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
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 immediately:
Signs of an allergic reaction, such as:
+ Rash or hives
+ Itching or red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing or tightness in the chest or throat
+ Difficulty breathing, swallowing, or talking
+ Unusual hoarseness or swelling of the mouth, face, lips, tongue, or throat
Note: In rare cases, allergic reactions can be fatal.
Signs of kidney problems, including:
+ Inability to urinate or changes in urine output
+ Blood in the urine or significant weight gain
Signs of electrolyte problems, such as:
+ Mood changes or confusion
+ Muscle pain, cramps, or spasms
+ Weakness, shakiness, or balance changes
+ Abnormal heartbeat or seizures
+ Loss of appetite or severe nausea and vomiting
Dizziness or fainting
Changes in balance
Fever, chills, or sore throat
Unexplained bruising or bleeding, or feeling extremely tired or weak
Muscle weakness
New or worsening breathing difficulties
Abnormal sensations, such as burning, numbness, or tingling
Twitching
Ringing in the ears, hearing loss, or other changes in hearing
Seizures
Confusion
Diarrhea, especially if it is severe or accompanied by stomach pain, cramps, or bloody stools (a rare but potentially life-threatening condition called C. diff-associated diarrhea, or CDAD, may occur)
A severe skin reaction (Stevens-Johnson syndrome or toxic epidermal necrolysis), characterized by:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Other Possible Side Effects
Most people do not experience significant side effects, but some may occur. If you notice any of the following symptoms, contact your doctor or seek medical attention if they bother you or do not resolve:
Headache
Diarrhea, upset stomach, or nausea and vomiting
Feeling tired or weak
Pain at the injection site
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact 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 immediately:
Signs of an allergic reaction, such as:
+ Rash or hives
+ Itching or red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing or tightness in the chest or throat
+ Difficulty breathing, swallowing, or talking
+ Unusual hoarseness or swelling of the mouth, face, lips, tongue, or throat
Note: In rare cases, allergic reactions can be fatal.
Signs of kidney problems, including:
+ Inability to urinate or changes in urine output
+ Blood in the urine or significant weight gain
Signs of electrolyte problems, such as:
+ Mood changes or confusion
+ Muscle pain, cramps, or spasms
+ Weakness, shakiness, or balance changes
+ Abnormal heartbeat or seizures
+ Loss of appetite or severe nausea and vomiting
Dizziness or fainting
Changes in balance
Fever, chills, or sore throat
Unexplained bruising or bleeding, or feeling extremely tired or weak
Muscle weakness
New or worsening breathing difficulties
Abnormal sensations, such as burning, numbness, or tingling
Twitching
Ringing in the ears, hearing loss, or other changes in hearing
Seizures
Confusion
Diarrhea, especially if it is severe or accompanied by stomach pain, cramps, or bloody stools (a rare but potentially life-threatening condition called C. diff-associated diarrhea, or CDAD, may occur)
A severe skin reaction (Stevens-Johnson syndrome or toxic epidermal necrolysis), characterized by:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Other Possible Side Effects
Most people do not experience significant side effects, but some may occur. If you notice any of the following symptoms, contact your doctor or seek medical attention if they bother you or do not resolve:
Headache
Diarrhea, upset stomach, or nausea and vomiting
Feeling tired or weak
Pain at the injection site
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact 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 or difficulty hearing
- Dizziness or vertigo
- Difficulty with balance or walking (ataxia)
- Muscle weakness or difficulty breathing
- Decreased urine output
- Swelling in the ankles, feet, or hands
- Numbness or tingling
- Rash, itching, or hives
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
Potential interactions with other medications or health conditions. This medication may interact with other prescription or over-the-counter (OTC) drugs, natural products, or vitamins, which could affect its safety and efficacy.
A complete list of all your current medications, including prescription and OTC drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions and ensure safe use.
Any existing health problems, as they may impact the safety and effectiveness of this medication.
To minimize risks and ensure safe use, do not start, stop, or change the dose of any medication without first consulting your doctor. It is crucial to verify that it is safe to take this medication with all your other medications and health conditions.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
Potential interactions with other medications or health conditions. This medication may interact with other prescription or over-the-counter (OTC) drugs, natural products, or vitamins, which could affect its safety and efficacy.
A complete list of all your current medications, including prescription and OTC drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions and ensure safe use.
Any existing health problems, as they may impact the safety and effectiveness of this medication.
To minimize risks and ensure safe use, do not start, stop, or change the dose of any medication without first consulting your doctor. It is crucial to verify that it is safe to take this medication with all your other medications and health conditions.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Regularly undergo blood work, hearing tests, and other laboratory tests as directed by your doctor to monitor your condition. Do not exceed the prescribed duration of treatment, as this may increase the risk of a secondary infection. If you have a known allergy to sulfites, consult your doctor before taking this medication, as some formulations may contain sulfites. Elderly patients (65 years or older) should exercise caution when using this drug, as they may be more susceptible to side effects. Additionally, if you are breastfeeding, discuss the potential risks to your baby with your doctor to determine the best course of action.
Overdose Information
Overdose Symptoms:
- Severe dizziness or vertigo
- Profound hearing loss
- Kidney failure (decreased urine, swelling)
- Neuromuscular blockade (muscle weakness, respiratory depression/paralysis)
What to Do:
Seek immediate medical attention. Overdose management may include hemodialysis to remove the drug from the blood, and supportive care for respiratory depression (e.g., mechanical ventilation) and electrolyte imbalances. Calcium salts may be used to reverse neuromuscular blockade. Call 1-800-222-1222 (Poison Control).
Drug Interactions
Major Interactions
- Nephrotoxic drugs (e.g., amphotericin B, cisplatin, cyclosporine, NSAIDs, vancomycin, loop diuretics like furosemide, ethacrynic acid): Increased risk of nephrotoxicity.
- Ototoxic drugs (e.g., loop diuretics, cisplatin, vancomycin): Increased risk of ototoxicity (auditory and vestibular).
- Neuromuscular blocking agents (e.g., succinylcholine, rocuronium, vecuronium): Potentiation of neuromuscular blockade, leading to respiratory depression/paralysis.
- Botulinum toxin: Increased risk of neuromuscular blockade.
Moderate Interactions
- Cephalosporins (especially cephaloridine, cephalothin): May increase risk of nephrotoxicity (less common with newer cephalosporins).
- Oral anticoagulants (e.g., warfarin): May potentiate anticoagulant effect by altering gut flora and vitamin K production.
- Indomethacin (in neonates): May increase tobramycin levels due to reduced renal clearance.
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Renal function (Serum Creatinine, BUN)
Rationale: Tobramycin is renally eliminated and can cause nephrotoxicity. Baseline assessment is crucial for dosing and monitoring.
Timing: Prior to initiation of therapy.
Electrolytes (Potassium, Magnesium, Calcium)
Rationale: Aminoglycosides can cause electrolyte disturbances, particularly hypomagnesemia and hypokalemia.
Timing: Prior to initiation of therapy.
Audiometry and Vestibular function tests
Rationale: Especially in patients with pre-existing hearing/balance issues, prolonged therapy, or high risk of ototoxicity.
Timing: Prior to initiation of therapy (if indicated).
Routine Monitoring
Serum Creatinine and BUN
Frequency: Daily or every 1-3 days, depending on patient stability and renal function.
Target: Within patient's baseline or acceptable limits.
Action Threshold: Increase of >0.5 mg/dL from baseline or >50% increase from baseline, or significant rise in BUN, warrants dose adjustment or discontinuation.
Tobramycin serum concentrations (Peak and Trough)
Frequency: Typically after 2-3 doses (for traditional dosing) or after first dose (for once-daily dosing), then as clinically indicated (e.g., weekly for stable patients, more frequently for unstable or renally impaired patients).
Target: Traditional: Peak 4-10 mcg/mL, Trough <2 mcg/mL. Once-daily: Peak 15-30 mcg/mL, Trough <1 mcg/mL (or undetectable).
Action Threshold: Trough levels >2 mcg/mL (traditional) or >1 mcg/mL (once-daily) indicate accumulation and increased risk of toxicity, requiring dose adjustment or extended interval. Subtherapeutic peak levels may indicate inadequate dosing.
Electrolytes (Potassium, Magnesium, Calcium)
Frequency: Weekly or as clinically indicated.
Target: Normal ranges.
Action Threshold: Abnormal levels require supplementation and/or re-evaluation of therapy.
Urinalysis (for proteinuria, casts)
Frequency: Weekly or as clinically indicated.
Target: Normal.
Action Threshold: New onset or worsening proteinuria/casts may indicate nephrotoxicity.
Symptom Monitoring
- Hearing loss (tinnitus, high-frequency hearing loss, difficulty understanding speech)
- Vestibular dysfunction (dizziness, vertigo, ataxia, nystagmus)
- Signs of kidney damage (decreased urine output, swelling, fatigue)
- Neuromuscular weakness or respiratory depression
- Hypersensitivity reactions (rash, itching, swelling, difficulty breathing)
Special Patient Groups
Pregnancy
Category D. Tobramycin 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 proven for tobramycin, the risk of ototoxicity and nephrotoxicity to the fetus cannot be excluded. Use only if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
Potential for teratogenicity, though data are limited. Risk of ototoxicity is generally considered to be throughout pregnancy.
Second Trimester:
Risk of ototoxicity and nephrotoxicity to the developing fetal kidney and inner ear.
Third Trimester:
Highest risk of ototoxicity and nephrotoxicity to the fetus due to increased fetal renal function and drug accumulation.
Lactation
L3 (Moderately Safe). Tobramycin is excreted into breast milk in small amounts. Oral absorption by the infant is poor, so systemic effects on the infant are unlikely. However, theoretical risks include alteration of infant gut flora, diarrhea, and interference with culture results if fever workup is needed. Monitor infant for diarrhea or candidiasis. Use with caution, or consider an alternative if possible.
Infant Risk:
Low systemic risk due to poor oral absorption, but potential for gut flora disruption.
Pediatric Use
Dosing requires careful calculation based on weight, age, and renal function. Therapeutic drug monitoring (TDM) is crucial to optimize efficacy and minimize toxicity, especially in neonates and infants due to variable pharmacokinetics. Neonates are particularly susceptible to nephrotoxicity and ototoxicity.
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 drug levels is essential. Hydration is important.
Clinical Information
Clinical Pearls
- Tobramycin exhibits concentration-dependent killing and a post-antibiotic effect, making once-daily dosing a viable and often preferred option for many infections, as it may reduce nephrotoxicity while maintaining efficacy.
- Therapeutic drug monitoring (TDM) with peak and trough levels is critical for optimizing therapy and minimizing toxicity, especially in patients with renal impairment, obesity, cystic fibrosis, or those receiving prolonged therapy.
- Ensure adequate hydration to minimize the risk of nephrotoxicity.
- Avoid concomitant use with other nephrotoxic or ototoxic drugs whenever possible. If co-administration is necessary, monitor renal function and auditory/vestibular function even more closely.
- Patients should be counseled on the importance of reporting any changes in hearing, balance, or urine output immediately.
- The 40mg/ml concentration is commonly used for IV/IM administration; ensure correct dilution and infusion rate for IV use (typically over 30-60 minutes).
Alternative Therapies
- Other aminoglycosides (e.g., gentamicin, amikacin)
- Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) for Gram-negative infections
- Cephalosporins (e.g., ceftazidime, cefepime) for Gram-negative infections
- Carbapenems (e.g., meropenem, imipenem/cilastatin) for broad-spectrum Gram-negative coverage
- Polymyxins (e.g., colistin) for multi-drug resistant Gram-negative infections (often as last resort)
Cost & Coverage
Average Cost:
Varies widely by supplier and contract per 50ml vial (40mg/ml)
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 a healthcare professional or pharmacist. 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 information about the medication taken, the amount, and the time it was taken, as this will aid in providing appropriate 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 a healthcare professional or pharmacist. 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 information about the medication taken, the amount, and the time it was taken, as this will aid in providing appropriate treatment.