Tobramycin adverse effects

In rats, ototoxicity caused by gentamicin or tobramycin was amehorated by melatonin, which did not interfere with the antibiotic action of the aminoglycosides (70). The free radical scavenging agent alpha-lipoic acid has previously been shown to protect against the cochlear adverse effects of systemically administered aminoglycoside antibiotics, and in a recent animal study it also prevented cochlear toxicity after the administration of neomycin 5% directly to the round window membrane over 7 days (71). 

Based on a study of 10 patients with automated peritoneal dialysis, it was recommended that for empirical treatment of dialysis-related peritonitis, the dosage of intermittent intraperitoneal tobramycin must be 1.5 mg/ kg for one exchange during the first day and then 0.5 mg/ kg thereafter, to reduce the risk of adverse effects (47). 

Nephrotoxicity Renal toxicity usually takes the form of acute tubular necrosis. This adverse effect, which is often reversible, is more common in elderly patients and in those concurrently receiving amphotericin B, cephalosporins, or vancomycin. Gentamicin and tobramycin are the most nephrotoxic. 

A survey of prescribing practices in 27 cystic fibrosis units in Australia showed an increase in the use of once-daUy aminoglycoside dosing and an increase in the reports of both ototoxicity and renal toxicity since 1999 (27-75% and 19-65% respectively) [3 ]. Tobramycin was the aminoglycoside of choice in all units. Exact details of these adverse effects were not given. 

Ototoxicity with both auditory and vestibulatory effects is the most serious of the adverse reactions of aminogycosides as it is mostly irreversible. Vestibular involvement manifests itself by dizziness, nystagmus, vertigo and ataxia. Cochlear toxicity results initially in high-frequency hearing loss. Amikacin more often causes cochlear damage than vestibular problems, while gentamicin and tobramycin are associated more frequently with vestibular symptoms. 

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