Increased gentamicin dosage requirements: rapid elimination in 249 gynecology patients

Wide interpatient variations were demonstrated in gentamicin elimination rate and dosage requirements for 249 gynecology patients with normal renal function. These variations combined with the need to obtain narrow ranges in serum levels necessitated measuring serum concentrations and individually calculating each patient's dose and dosing interval. Optimal peak and trough serum concentrations were reliably and rapidly achieved by means of this method. Required dosage regimens ranged from 1.9 to 14.0 mg/kg/day. Ototoxicity and nephrotoxicity did not occur in these patients. These results further emphasize the need to measure serum concentrations and make necessary dosage adjustments to ensure therapeutic levels. However, because of the wide interpatient variation, these increased dosages are not routinely suggested without previously measuring serum concentrations and calculating each patient's dosage regimen.