Tobramycin (Injection, Solution)

Active ingredient: Tobramycin sulfate
Description: Tobramycin sulfate, a water-soluble antibiotic of the aminoglycoside group, is derived from the actinomycete Streptomyces tenebrarius. Tobramycin Injection 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 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-��-D-glucopyranosyl-(1���4)-O-[2,6-diamino-2,3,6-trideoxy-��-D-ribo-hexopyranosyl-(1���6)]-2-deoxy-L-streptamine (2:5)(salt) and has the chemical formula (CHNO)���5HSO. The molecular weight is 1,425.39. The structural formula for tobramycin is as follows: A pharmacy bulk package is a container of a sterile preparation for parenteral use that contains many single doses. The contents are intended for use in a pharmacy admixture service and are restricted to the preparation of admixtures for intravenous infusion (see DOSAGE AND ADMINISTRATION, Directions for proper use of Pharmacy Bulk Package).
Indication:
Tobramycin 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 Citrobacter sp Aminoglycosides, including tobramycin sulfate, 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 etiologicorganisms 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 sulfate may be initiated before the results of susceptibility studies areobtained. 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 and other antibacterial drugs, tobramycin 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.
Contraindication:
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.
Non-proprietary / generic name: Tobramycin sulfate
Adverse Outcome:
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, 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.
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