Routine monitoring of gentamicin serum concentrations in pediatric patients with normal renal function is unnecessary

OBJECTIVE: Due to increasing demands for cost containment within the healthcare system, we evaluated the need for routine gentamicin concentrations (i.e., peak and trough with third dose). DESIGN: Single-institution study performed concurrently with hospitalization. SETTING: A 225-bed pediatric teaching hospital. PARTICIPANTS: The study population consisted of 150 hospitalized pediatric patients (53% medicine, 47% surgical patients) from 3 months to 15 years old with normal serum creatinine. OUTCOME MEASURES: If the administered dose produced diagnoses-appropriate peak concentrations of at least 4 micrograms/mL or 5 micrograms/mL in bacteremia/septicemia and at least 6 micrograms/mL or 8 micrograms/mL in patients with pneumonia if trough serum gentamicin concentrations were less than 2 micrograms/mL, if the patient was noted by the attending physician to be clinically responding as well as objectively having a decreased white blood cell count and was afebrile, and if there was not an increase of 0.5 mg/dL or more in serum creatinine during the course of therapy. RESULTS: Patients received a mean dose of gentamicin 2.51 +/- 0.14 mg/kg i.v. q8h, which resulted in a mean peak concentration of 6.1 +/- 1.7 micrograms/mL (range 2.4-11.7) and a mean trough concentration of 0.5 +/- 0.3 microgram/mL (range 0.1-1.8). Peak and trough concentrations were at least 4 micrograms/mL and less than 2 micrograms/mL in 96% and 100% of patients, respectively. No patient required a dosage change due to lack of clinical response. CONCLUSIONS: Our data do not support the routine monitoring of gentamicin concentrations in pediatric patients older than 3 months of age who are receiving appropriate standard doses of gentamicin and have normal renal function.