Tobramycin
FDA Drug Information • Also known as: Bethkis, Kitabis Pak, Tobi, Tobi Podhaler, Tobramycin, Tobramycin Inhalation Solution Pak, Tobrex
- Brand Names
- Bethkis, Kitabis Pak, Tobi, Tobi Podhaler, Tobramycin, Tobramycin Inhalation Solution Pak, Tobrex
- Drug Class
- Aminoglycoside Antibacterial [EPC]
- Route
- OPHTHALMIC
- Dosage Form
- SOLUTION/ DROPS
- Product Type
- HUMAN PRESCRIPTION DRUG
⚠ Boxed Warning (Black Box)
WARNINGS Patients treated with Tobramycin Injection and other aminoglycosides should be under close clinical observation, because these drugs have an inherent potential for causing ototoxicity and nephrotoxicity. Neurotoxicity, manifested as both auditory and vestibular ototoxicity, can occur. The auditory changes are irreversible, are usually bilateral, and may be partial or total. Eighth-nerve impairment and nephrotoxicity may develop, primarily in patients having pre-existing renal damage and in those with normal renal function to whom aminoglycosides are administered for longer periods or in higher doses than those recommended. Other manifestations of neurotoxicity may include numbness, skin tingling, muscle twitching, and convulsions. The risk of aminoglycoside-induced hearing loss increases with the degree of exposure to either high peak or high trough serum concentrations. Patients who develop cochlear damage may not have symptoms during therapy to warn them of eighth-nerve toxicity, and partial or total irreversible bilateral deafness may continue to develop after the drug has been discontinued. Rarely, nephrotoxicity may not become apparent until the first few days after cessation of therapy. Aminoglycoside-induced nephrotoxicity usually is reversible. Renal and eighth-nerve function should be closely monitored in patients with known or suspected renal impairment and also in those whose renal function is initially normal but who develop signs of renal dysfunction during therapy. Peak and trough serum concentrations of aminoglycosides should be monitored periodically during therapy to assure adequate levels and to avoid potentially toxic levels. Prolonged serum concentrations above 12 mcg/mL should be avoided. Rising trough levels (above 2 mcg/mL) may indicate tissue accumulation. Such accumulation, excessive peak concentrations, advanced age, and cumulative dose may contribute to ototoxicity and nephrotoxicity (see PRECAUTIONS ). Urine should be examined for decreased specific gravity and increased excretion of protein, cells, and casts. Blood urea nitrogen, serum creatinine, and creatinine clearance should be measured periodically. When feasible, it is recommended that serial audiograms be obtained in patients old enough to be tested, particularly high-risk patients. Evidence of impairment of renal, vestibular, or auditory function requires discontinuation of the drug or dosage adjustment. Tobramycin should be used with caution in premature and neonatal infants because of their renal immaturity and the resulting prolongation of serum half-life of the drug. Concurrent and sequential use of other neurotoxic and/or nephrotoxic antibiotics, particularly other aminoglycosides (e.g., amikacin, streptomycin, neomycin, kanamycin, gentamicin, and paromomycin), cephaloridine, viomycin, polymyxin B, colistin, cisplatin, and vancomycin, should be avoided. Other factors that may increase patient risk are advanced age and dehydration. Aminoglycosides should not be given concurrently with potent diuretics, such as ethacrynic acid and furosemide. Some diuretics themselves cause ototoxicity, and intravenously administered diuretics enhance aminoglycoside toxicity by altering antibiotic concentrations in serum and tissue. Aminoglycosides can cause fetal harm when administered to a pregnant woman (see PRECAUTIONS ).
Description
DESCRIPTION Tobramycin sulfate, a water-soluble antibiotic of the aminoglycoside group, is derived from the actinomycete Streptomyces tenebrarius . Tobramycin Injection, USP is a clear and colorless sterile aqueous solution for parenteral administration. Each mL contains tobramycin sulfate equivalent to 40 mg tobramycin; sodium metabisulfite added as an antioxidant, 3.2 mg; and edetate disodium added as a stabilizer, 0.1 mg. Contains sulfuric acid and may contain sodium hydroxide for pH adjustment. pH 4.0 (3.0 to 6.5). Tobramycin sulfate is O -3-amino-3-deoxy- α -D-glucopyranosyl-(1→4)- O -[2,6-diamino-2,3,6-trideoxy- α -D- ribo -hexopyranosyl-(1→6)]-2-deoxy-L-streptamine, sulfate (2:5) (salt) and has the chemical formula (C 18 H 37 N 5 O 9 ) 2
What Is Tobramycin Used For?
INDICATIONS AND USAGE Tobramycin injection is indicated for the treatment of serious bacterial infections caused by susceptible strains of the designated microorganisms in the diseases listed below: Septicemia in the neonate, child, and adult caused by P. aeruginosa , E. coli , and Klebsiella sp Lower respiratory tract infections caused by P. aeruginosa , Klebsiella sp, Enterobacter sp, Serratia sp, E. coli , and S. aureus (penicillinase- and non-penicillinase-producing strains) Serious central-nervous-system infections (meningitis) caused by susceptible organisms Intra-abdominal infections, including peritonitis, caused by E. coli , Klebsiella sp, and Enterobacter sp. Skin, bone, and skin structure infections caused by P. aeruginosa , Proteus sp, E. coli , Klebsiella sp, Enterobacter sp and S. aureus Complicated and recurrent urinary tract infections caused by P. aeruginosa, Proteus sp, (indole-positive and indole- negative), E. coli , Klebsiella sp, Enterobacter sp, Serratia sp, S. aureus , Providencia sp, and Citrobacte r sp. Aminoglycosides, including tobramycin, are not indicated in uncomplicated initial episodes of urinary tract infections unless the causative organisms are not susceptible to antibiotics having less potential toxicity. Tobramycin may be considered in serious staphylococcal infections when penicillin or other potentially less toxic drugs are contraindicated and when bacterial susceptibility testing and clinical judgment indicate its use. Bacterial cultures should be obtained prior to and during treatment to isolate and identify etiologic organisms and to test their susceptibility to tobramycin. If susceptibility tests show that the causative organisms are resistant to tobramycin, other appropriate therapy should be instituted. In patients in whom a serious life-threatening gram- negative infection is suspected, including those in whom concurrent therapy with a penicillin or cephalosporin and an aminoglycoside may be indicated, treatment with tobramycin may be initiated before the results of susceptibility studies are obtained. The decision to continue therapy with tobramycin should be based on the results of susceptibility studies, the severity of the infection, and the important additional concepts discussed in the WARNINGS box above. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Tobramycin Injection and other antimicrobial drugs, Tobramycin Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antimicrobial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
Dosage and Administration
DOSAGE AND ADMINISTRATION Tobramycin may be given intramuscularly or intravenously. Recommended dosages are the same for both routes. This insert is for a Pharmacy Bulk Package and is intended for preparing I.V. admixtures only. Dosage recommendations for intramuscular use are for informational purposes only. The patient’s pretreatment body weight should be obtained for calculation of correct dosage. It is desirable to measure both peak and trough serum concentrations (see WARNINGS box and PRECAUTIONS ). Administration for Patients with Normal Renal Function— Adults with Serious Infections : 3 mg/kg/day in 3 equal doses every 8 hours (see Table 3). Adults with Life-Threatening Infections : Up to 5 mg/kg/day may be administered in 3 or 4 equal doses (see Table 3). The dosage should be reduced to 3 mg/kg/day as soon as clinically indicated. To prevent increased toxicity due to excessive blood levels, dosage should not exceed 5 mg/kg/day unless serum levels are monitored (see WARNINGS box and PRECAUTIONS ). Table 3 DOSAGE SCHEDULE GUIDE FOR TOBRAMYCIN INJECTION, USP IN ADULTS WITH NORMAL RENAL FUNCTION (Dosage at 8-Hour Intervals) For Patient Weighing Usual Dose for Serious Infections 1 mg/kg q8h (Total, 3mg/kg/day) Maximum Dose for Life-Threatening Infections (Reduce as soon as possible) 1.66 mg/kg q8h (Total, 5 mg/kg/day) kg lb mg/dose mL/dose* mg/dose mL/dose* q8h q8h 120 264 120 mg 3 mL 200 mg 5 mL 115 253 115 mg 2.9 mL 191 mg 4.75 mL 110 242 110 mg 2.75 mL 183 mg 4.5 mL 105 231 105 mg 2.6 mL 175 mg 4.4 mL 100 220 100 mg 2.5 mL 166 mg 4.2 mL 95 209 95 mg 2.4 mL 158 mg 4 mL 90 198 90 mg 2.25 mL 150 mg 3.75 mL 85 187 85 mg 2.1 mL 141 mg 3.5 mL 80 176 80 mg 2 mL 133 mg 3.3 mL 75 165 75 mg 1.9 mL 125 mg 3.1 mL 70 154 70 mg 1.75 mL 116 mg 2.9 mL 65 143 65 mg 1.6 mL 108 mg 2.7 mL 60 132 60 mg 1.5 mL 100 mg 2.5 mL 55 121 55 mg 1.4 mL 91 mg 2.25 mL 50 110 50 mg 1.25 mL 83 mg 2.1 mL 45 99 45 mg 1.1 mL 75 mg 1.9 mL 40 88 40 mg 1 mL 66 mg 1.6 mL * Applicable to all product forms except Tobramycin Injection, USP, 10 mg/mL (Pediatric) Pediatric Patients ( Greater than 1 Week of Age ): 6 to 7.5 mg/kg/day in 3 or 4 equally divided doses (2 to 2.5 mg/kg every 8 hours or 1.5 to 1.89 mg/kg every 6 hours). Premature or Full-Term Neonates 1 Week of Age or Less : Up to 4 mg/kg/day may be administered in 2 equal doses every 12 hours. It is desirable to limit treatment to a short term. The usual duration of treatment is 7 to 10 days. A longer course of therapy may be necessary in difficult and complicated infections. In such cases, monitoring of renal, auditory, and vestibular functions is advised, because neurotoxicity is more likely to occur when treatment is extended longer than 10 days. Dosage in Patients with Cystic Fibrosis — In patients with cystic fibrosis, altered pharmacokinetics may result in reduced serum concentrations of aminoglycosides. Measurement of tobramycin serum concentration during treatment is especially important as a basis for determining...
Side Effects (Adverse Reactions)
ADVERSE REACTIONS Neurotoxicity — Adverse effects on both the vestibular and auditory branches of the eighth nerve have been noted, especially in patients receiving high doses or prolonged therapy, in those given previous courses of therapy with an ototoxin, and in cases of dehydration. Symptoms include dizziness, vertigo, tinnitus, roaring in the ears, and hearing loss. Hearing loss is usually irreversible and is manifested initially by diminution of high-tone acuity. Tobramycin and gentamicin sulfates closely parallel each other in regard to ototoxic potential. Nephrotoxicity — Renal function changes, as shown by rising BUN, NPN, and serum creatinine and by oliguria, cylindruria, and increased proteinuria, have been reported, especially in patients with a history of renal impairment who are treated for longer periods or with higher doses than those recommended. Adverse renal effects can occur in patients with initially normal renal function. Clinical studies and studies in experimental animals have been conducted to compare the nephrotoxic potential of tobramycin and gentamicin. In some of the clinical studies and in the animal studies, tobramycin caused nephrotoxicity significantly less frequently than gentamicin. In some other clinical studies, no significant difference in the incidence of nephrotoxicity between tobramycin and gentamicin was found. Other reported adverse reactions possibly related to tobramycin sulfate include anemia, granulocytopenia, and thrombocytopenia; and fever, rash, exfoliative dermatitis, itching, urticaria, nausea, vomiting, diarrhea, headache, lethargy, pain at the injection site, mental confusion, and disorientation. Laboratory abnormalities possibly related to tobramycin include increased serum transaminases (SGOT, SGPT); increased serum LDH and bilirubin; decreased serum calcium, magnesium, sodium, and potassium; and leukopenia, leukocytosis, and eosinophilia.
Warnings and Precautions
WARNINGS See WARNINGS box above. This product contains sodium metabisulfite, a sulfite that may cause allergic-type reactions, including anaphylactic symptoms and life-threatening or less severe asthmatic episodes, in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in non-asthmatic people. Serious allergic reactions including anaphylaxis and dermatologic reactions including exfoliative dermatitis, toxic epidermal necrolysis, erythema multiforme, and Stevens-Johnson Syndrome have been reported rarely in patients on tobramycin therapy. Although rare, fatalities have been reported (see CONTRAINDICATIONS ). If an allergic reaction occurs, the drug should be discontinued and appropriate therapy instituted. Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Tobramycin, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile. C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated. Risk of Ototoxicity Due to Mitochondrial DNA Variants Cases of ototoxicity with aminoglycosides have been observed in patients with certain variants in the mitochondrially encoded 12S rRNA gene ( MT-RNR1 ), particularly the m.1555A>G variant. Ototoxicity occurred in some patients even when their aminoglycoside serum levels were within the recommended range. Mitochondrial DNA variants are present in less than 1% of the general US population, and the proportion of the variant carriers who may develop ototoxicity as well as the severity of ototoxicity is unknown. In case of known maternal history of ototoxicity due to aminoglycoside use or a known mitochondrial DNA variant in the patient, consider alternative treatments other than aminoglycosides unless the increased risk of permanent hearing loss is outweighed by the severity of infection and lack of safe and effective alternative therapies.
Contraindications
CONTRAINDICATIONS A hypersensitivity to any aminoglycoside is a contraindication to the use of tobramycin. A history of hypersensitivity or serious toxic reactions to aminoglycosides may also contraindicate the use of any other aminoglycoside because of the known cross-sensitivity of patients to drugs in this class.
Overdosage
OVERDOSAGE Signs and Symptoms— The severity of the signs and symptoms following a tobramycin overdose are dependent on the dose administered, the patient’s renal function, state of hydration, and age and whether or not other medications with similar toxicities are being administered concurrently. Toxicity may occur in patients treated more than 10 days, in adults given more than 5 mg/kg/day, children given more than 7.5 mg/kg/day, or patients with reduced renal function whose dose has not been appropriately adjusted. Nephrotoxicity following the parenteral administration of an aminoglycoside is most closely related to the area under the curve of the serum concentration versus time graph. Nephrotoxicity is more likely if trough blood concentrations fail to fall below 2 mcg/mL and is also proportional to the average blood concentration. Patients who are elderly, have abnormal renal function, are receiving other nephrotoxic drugs, or are volume depleted are at greater risk for developing acute tubular necrosis. Auditory and vestibular toxicities have been associated with aminoglycoside overdose. These toxicities occur in patients treated longer than 10 days, in patients with abnormal renal function, in dehydrated patients, or in patients receiving medications with additive auditory toxicities. These patients may not have signs or symptoms or may experience dizziness, tinnitus, vertigo, and a loss of high-tone acuity as ototoxicity progresses. Ototoxicity signs and symptoms may not begin to occur until long after the drug has been discontinued. Neuromuscular blockade or respiratory paralysis may occur following administration of many aminoglycosides. Neuromuscular blockade, respiratory failure, and prolonged respiratory paralysis may occur more commonly in patients with myasthenia gravis or Parkinson’s disease. Prolonged respiratory paralysis may also occur in patients receiving decamethonium, tubocurarine, or succinylcholine. If neuromuscular blockade occurs, it may...
How Supplied
HOW SUPPLIED Tobramycin Injection, USP, is available as: NDC No. Strength Fill Volume 68083-241-01 40 mg per mL 50 mL in a 50 mL vial, packaged individually Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. This container closure is not made with natural rubber latex. Manufactured by: Gland Pharma Limited D.P.Pally, Dundigal Post Hyderabad - 500043, INDIA Revised: 02/2023
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.