Editor,—The commentary by Lenney correctly points out that clinicians are often slow to apply good research evidence to clinical practice.1 However, the choice of once daily intravenous gentamicin to illustrate this point is unfortunate. Extended interval aminoglycoside dosing is widely used in paediatric and neonatal practice for the treatment of serious gram negative infections, the treatment of newborn infants with sepsis, and the treatment of chronic Pseudomonas aeruginosainfection in patients with cystic fibrosis. However, the implementation of extended interval dosing has not been based on the results of appropriately designed trials in children and neonates.

The largest meta-analysis of single versus multiple daily dosing of aminoglycosides for the treatment of gram negative sepsis included only 2 paediatric studies.2 The use of once daily aminoglycosides in children and the newborn is still currently unlicensed. Finally, a recent systematic review of once daily versus multiple daily dosing of aminoglycosides in CF concluded that there was insufficient evidence to recommend a change in practice.3This was because most clinical trials were of insufficient quality or were performed in adults and so the results should not be extrapolated to children.

We argue that the presence of evidence from “a number of studies from numerous countries” should not be the basis on which implementations in practice should be founded. Instead, quality of evidence should be of paramount importance, even if there is little of it.