Aminoglycoside-associated hypomagnesaemia in children with cystic fibrosis

Hypomagnesaemia in children with cystic fibrosis (CF) is under-recognized. We report a child with CF who developed significant hypomagnesaemia followi ng intravenous (i.v.) treatment with aminoglycosides for exacerbations of P seudomonas aeruginosa infection. Three additional cases have also been obse rved. Investigations in two patients have revealed excessive renal loss of magnesium. It is postulated that renal tubular damage secondary to the cumu lative effects of repeated courses of aminoglycosides resulted in hypomagne saemia, and we suggest screening for this problem by monitoring serum magne sium regularly in all patients with CF receiving multiple courses of aminog lycosides.