Extended-interval once-daily dosing of aminoglycosides in adult and pediatric patients with cystic fibrosis.

Extended-interval once-daily dosing with the aminoglycoside tobramycin has been proven to be equally efficacious as traditional thrice-daily dosing for treatment of the pulmonary exacerbations of cystic fibrosis in adults and children older than 5 years. The frequencies of acute ototoxicity and nephrotoxicity do not appear to be significantly different between patients treated with once- versus thrice-daily dosing, and the risk of acute nephrotoxicity may actually be lower in pediatric patients when once-daily dosing is used. Long-term studies are needed to fully assess the impact that cumulative treatments with once-daily dosing have on renal and auditory function. An increase in antimicrobial resistance has been suggested with once-daily dosing in the cystic fibrosis population. The extended-interval aminoglycoside dose should be determined based on previous therapeutic drug monitoring. If the patient is aminoglycoside (tobramycin) naïve, a dose of 10 mg/kg once/day is suggested, with the dose adjusted by using therapeutic drug monitoring to individualize therapy.