Once daily dosing of gentamicin has been shown to be at least as effective as and not more toxic than a multiple daily dosing regimen. Monitoring peak and trough levels with once daily dosing is generally not suitable. For most patients a nomogram is the method of choice in order to confirm or modify dosing intervals. For a daily dose of 7mg/kg/day the Hartford nomogram can be used. Gentamicin levels should be taken 6-14 hours after the start of the infusion. For a daily dose of 5mg/kg/day the Urban-Craig nomogram can be used. Gentamicin levels should be taken 8-12 hours after the dose. It is essential that the time the gentamicin infusion was started and the time the sample was taken are documented accurately.