Aminoglycoside-associated Fanconi's syndrome: an underrecognized entity.

The Fanconi syndrome is an array of multiple proximal renal tubular dysfunctions occurring in association with several exogenous toxins, such as aminoglycosides. These antibiotics remain the drugs of choice in most gram-negative infections, but nephrotoxicity is the main drawback for them. Furthermore, the nephrotoxic effects may be overlooked with routine analyses. With the purpose of making physicians aware of this underrecognized complication, we are reporting here 3 cases of Fanconi's syndrome related to the administration of high-dose aminoglycosides (ranging from 3.6 to 15 g) with normal serum urea nitrogen and creatinine levels. The pattern of aminoaciduria demonstrated high increases in neutral amino acids, followed by dibasic and near-normal acidic amino acids. We also report the urinary excretion rates of total protein and beta2-microglobulin and protein electrophoresis results. We compared these cases with others reported in the literature.