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tobramycin (Nebcin, Tobrex)

Tradename: Nebcin. Indications: - bacterial infections due to susceptible organisms - Pseudomonas aeruginosa infection - non-pseudomonal enteric bacillus more susceptible to tobramycin than gentamicin bases on antibiotic sensitivity - lower respiratory tract infections - CNS infections - bacterial meningitis [8] - intra-abdominal infections - skin infection - osteomyelitis - urinary tract infections - empiric therapy in patients with cystic fibrosis & immunocompromised patients - empiric therapy for fever of unknown origin [8] - empiric therapy for febrile neutropenia [8] - topical agent use to treat superficial ophthalmic infections - keratoconjunctivitis - blepharoconjunctivitis - meibomitis - dacryocystitis - corneal perforation - anterior uveitis - keratitis - corneal abrasion [8] Dosage: Adults: 1.0-1.7 mg/kg IV/IM every 8 hours. Children: 2-2.5 mg/kg every 8 hours. Injection: (sulfate) 10 mg/mL (2 mL), 40 mg/mL (2 mL) Inhalation: - handheld inhaler containing a powder formulation of tobramycin, to treat P aeruginosa infections in cystic fibrosis [7] Ophthalmic agent: Tradename: Tobrex. 1) 0.3% ointment every 3-4 hours or BID-QID 2) 0.3% drops every 1-6 hours Ointment: (ophthalmic) 0.3% (3.5 g) Solution: (ophthalmic) 0.3% (5 mL) Monitor: Therapeutic drug monitoring: - therapeutic range: - Peak: 4-8 ug/mL. - Trough: 1-2 ug/mL. Dosage adjustment in renal failure: creatinine clearance dosage > 50-90 mL/min 60-90% every 8-12 hours 10-50 mL/min* 30-70% every 12 hours < 10 mL/min 20-30% every 24-48 hours > 80 mL/min 5.1 mg/kg every 24 hours 60-80 mL/min 4 mg/kg every 24 hours 40-60 mL/min 3.5 mg/kg every 24 hours 30-40 mL/min 2.5 mg/kg every 24 hours 20-30 mL/min 4 mg/kg every 48 hours 10-20 mL/min 3 mg/kg every 48 hours < 10 mL/min# 2 mg/kg every 48 hours * same dose for continuous arteriovenous hemofiltration # 2.5 mg/kg after hemodialysis Pharmacokinetics: - 1/2life 2-3 hours (20-60 hours ESRD) - Dialyzable: 50-100%. Antimicrobial activity: Gram positive - Enterococcus faecalis (synergy with penicillins) - Staphylococcus aureus (MSSA) - Staphylococcus epidermidis (+/-) Gram negative - Neisseria gonorrhoeae - Moraxella catarrhalis - Haemophilus influenzae - Escherichia coli - Klebsiella species - Enterobacter species - Serratia marcescens - Proteus vulgaris - Proteus mirabilis - Acinetobacter species - Pseudomonas aeruginosa* - Yersinia enterocolitica - Providencia [8] - Citrobacter [8] Atypical bacteria - Mycobacterium avium * more active than gentamicin against Pseudomonas aeruginosa. Adverse effects: 1) not common (1-10%) - nephrotoxicity, neurotoxicity, ototoxicity* 2) uncommon (< 1%) - rash, drug fever, headache, paresthesia, tremor, nausea/vomiting, eosinophilia, arthralgia, anemia, hypotension, dyspnea, drowsiness, weakness, lacrimation, itching, edema of the eyelid, keratitis *ototoxicity (auditory & vestibular) 1) tinnitus 2) vestibular toxicity may occur up to 2-3 months after stopping drug Laboratory: 1) specimen: serum, plasma (EDTA, heparin) 2) methods: RIA, MB, HPLC, GLC, REA, EIA, FPIA 3) see tobramycin in serum or plasma

Interactions

drug interactions drug adverse effects of aminoglycosides

Related

tobramycin in serum/plasma

Specific

Tobramycin Ophthalmic

General

aminoglycoside antibiotic

Properties

MISC-INFO: elimination route KIDNEY 1/2life 2-3 HOURS therapeutic-range 5-10 UG/ML <4 UG/ML toxic-range >12 UG/ML >4 UG/ML protein-binding <5% elimination by hemodialysis + peritoneal dialysis +/- pregnancy-category D B safety in lactation ?

Database Correlations

PUBCHEM correlations

References

  1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
  2. Harrison's Principles of Internal Medicine, 13th ed. Companion Handbook. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1995, pg 163
  3. Sanford Guide to antimicrobial therapy 1997, 2001
  4. Kaiser Permanente Northern California Regional Drug Formulary, 1998
  5. Clinical Guide to Laboratory Tests, NW Tietz (ed) 3rd ed, WB Saunders, Philadelpha 1995
  6. Department of Veterans Affairs, VA National Formulary
  7. FDA News Release: March 22, 2013 FDA approves TOBI Podhaler to treat a type of bacterial lung infection in cystic fibrosis patients. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm345123.htm
  8. Deprecated Reference

Component-of

dexamethasone/tobramycin (Tobradex) fluorometholone/tobramycin loteprednol/tobramycin