Bactericidal aminoglycoside (anti-Pseudomonas)
Tobramycin is an antibiotic of the aminoglycoside class, given by injection for the treatment of serious bacterial infections, especially due to Pseudomonas aeruginosa (respiratory infections, septicaemia, complicated urinary tract infections, meningitis, intra-abdominal infections). It works by preventing bacterial protein synthesis. It is a hospital-use drug: it can cause kidney damage and ear damage (ototoxicity), so it requires monitoring of levels and renal function.
Also known as: Tobrex, TOBI
Combining Tobramycin with Vancomycin increases the risk of nephrotoxicity and ototoxicity through an additive effect on the kidney and the inner ear.
Vancomycin and tobramycin (an aminoglycoside) have overlapping nephro- and ototoxicity: the vancomycin label warns that "systemic exposure may result in acute kidney injury" and the tobramycin label that aminoglycosides "have an inherent potential for causing ototoxicity and nephrotoxicity", with "aminoglycoside-induced hearing loss increasing with the degree of exposure to either high peak or high trough serum concentrations". The nephrotoxicity of the combination is well documented and the risk increases with pre-existing renal impairment, hypovolaemia, prolonged use or high doses. Monitor creatinine and urine output, vancomycin and tobramycin levels, and hearing/balance; adjust doses to creatinine clearance and limit the duration of combined therapy.
Vancomycin + tobramycin: overlapping and additive nephro- and ototoxicity. Monitor renal function, levels and hearing, especially in the elderly and renally impaired.
Vancomycin and Tobramycin (aminoglycoside) have overlapping nephrotoxicity and ototoxicity; co-administration potentiates renal and cochlear/vestibular injury, with added risk in renal impairment.
Monitor renal function, serum levels and ototoxicity signs during the combination.
Rising creatinine, oliguria, tinnitus or hearing loss require immediate reassessment.
Avoid the combination; if unavoidable, minimize duration and adjust doses to renal function.
DailyMed/FDA (NIH/NLM) — approved Tobramycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c4751a4f-c9c1-60c5-e053-2995a90aeba9 ; approved Vancomycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=b01aaa02-8f1d-4b57-96a5-337503428af1 — with additional reference: Prontuário Terapêutico do INFARMED, INFARMED (11th ed., 2012)
Combining Tobramycin with Furosemide increases the risk of ototoxicity and nephrotoxicity through an additive effect on the inner ear and the kidney.
Tobramycin (aminoglycoside) is ototoxic and nephrotoxic, and the tobramycin label states that aminoglycosides should not be given concurrently with potent diuretics such as ethacrynic acid and furosemide, because some diuretics cause ototoxicity on their own and intravenous diuretics can increase aminoglycoside toxicity by altering its serum and tissue concentrations. The furosemide label adds that it may increase the ototoxic potential of aminoglycosides, especially with impaired renal function, and advises against the combination except in life-threatening situations. If unavoidable, monitor renal function, aminoglycoside levels, audiometry and vestibular signs.
Furosemide + tobramycin: additive ototoxicity and nephrotoxicity. Avoid the combination, except in life-threatening situations.
Tobramycin (aminoglycoside) and Furosemide (loop diuretic) share cochlear/vestibular and renal toxicity; combined use sums these effects, with greater risk when renal function is impaired.
Monitor renal function, diuresis, electrolytes and ototoxicity signs; tobramycin serum levels when indicated.
Tinnitus, vertigo, hearing loss or worsening renal function require prompt discontinuation and reassessment.
Avoid the combination; if unavoidable, shorten the course, optimize hydration and adjust doses to renal function.
DailyMed/FDA (NIH/NLM) — approved Tobramycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c4751a4f-c9c1-60c5-e053-2995a90aeba9 ; approved Furosemide label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7cdcd001-ab4b-4210-a455-2e17a7bc4972 — with additional reference: Prontuário Terapêutico do INFARMED, INFARMED (11th ed., 2012)
Tobramycin is given intravenously, by inhalation or ophthalmically; food does not affect its systemic pharmacokinetics.
May be administered regardless of meals.
DailyMed/FDA (NIH/NLM) — approved Tobramycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c4751a4f-c9c1-60c5-e053-2995a90aeba9
No relevant pharmacokinetic interaction, but alcohol can worsen vestibular symptoms and dehydration.
Moderate alcohol intake during treatment.
DailyMed/FDA (NIH/NLM) — approved Tobramycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c4751a4f-c9c1-60c5-e053-2995a90aeba9
Tobramycin is eliminated renally; renal impairment increases the risk of nephrotoxicity and ototoxicity.
Adjust the dose and monitor serum levels and renal function.
DailyMed/FDA (NIH/NLM) — approved Tobramycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c4751a4f-c9c1-60c5-e053-2995a90aeba9
Aminoglycosides are ototoxic; patients with pre-existing hearing loss or vestibular disease are at increased risk.
Monitor for ototoxic symptoms and consider audiometry in prolonged treatment.
DailyMed/FDA (NIH/NLM) — approved Tobramycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c4751a4f-c9c1-60c5-e053-2995a90aeba9
Aminoglycosides can cause fetal ototoxicity; use only if the benefit outweighs the risk.
Use only in severe infections when there is no alternative.
Present in breast milk in small amounts; the ototoxicity risk to the infant is considered low.
No specific contraception required.
DailyMed/FDA (NIH/NLM) — approved Tobramycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c4751a4f-c9c1-60c5-e053-2995a90aeba9
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Bactericidal aminoglycoside active against Gram-negatives (including Pseudomonas aeruginosa), used in severe hospital infections (sepsis, pneumonia, complicated urinary tract infections, meningitis). Nephrotoxicity and ototoxicity (vestibular and auditory) are the limiting effects — requires level and renal function monitoring.
Bactericidal aminoglycoside that binds the bacterial 30S ribosomal subunit, causing mRNA misreading and defective protein synthesis, with disruption of the cytoplasmic membrane. Prolonged post-antibiotic effect; concentration-dependent activity.
Well absorbed intramuscularly (peak 30-90 min; ~4 mcg/mL after 1 mg/kg); IV infusion produces levels similar to IM; virtually unabsorbed from the GI tract (not used orally for systemic effect). No relevant protein binding.
Virtually no metabolism; elimination almost exclusively by glomerular filtration (up to 84% of the dose in urine within 8 h and 93% within 24 h with normal renal function; renal clearance similar to creatinine). Accumulation in renal impairment.
Serum half-life ~2 h in individuals with normal renal function; inverse relationship between half-life and creatinine clearance (extend the dosing interval in renal impairment).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
