Therapeutic drug monitoring of once daily gentamicin in serum and saliva of children

Gentamicin is widely used in paediatric medicine and therapeutic monitoring is mandatory due to the narrow margin of safety. Saliva sampling may be of potential interest, especially in children in whom blood sampling is often difficult. Experience with once daily intravenous administration of aminog lycosides has grown in recent years. Gentamicin levels were measured in ser um and saliva of 55 children treated with the drug (5 mg/kg per day), admin istered intravenously in three different regimens: thrice (n = 19), twice ( n = 18), and once daily (n = 18). No correlation was found between serum ge ntamicin concentrations and saliva levels when the drug was administered tw ice or thrice daily, however, there was good correlation when the drug was administered once daily (r(2) = 0.96, P < 0.0001). Conclusion In children with uncomplicated infections treated with once dail y gentamicin, trough concentrations of the drug can be monitored in saliva.