Effect of Vasopressin Infusion Rate on Vancomycin Dose Adjustment in Pediatric Central Diabetes Insipidus: Grand Round/A Case Study.
Hiroyuki Ono, Sho Tashiro, Ryota Tanaka et al.
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Case in brief
A 9-month-old infant with trauma-associated central diabetes insipidus received continuous arginine vasopressin (AVP) and vancomycin for suspected postoperative surgical-site infection. Vancomycin trough concentration was initially 6.3 mcg/mL on 90 mg every 6 hours, prompting an increase to 140 mg every 6 hours; the trough then reached 19.0 mcg/mL. After returning to 90 mg every 6 hours, the trough was 10.5 mcg/mL as the AVP infusion rate had been increased to 3.2 mL/h. Urine output remained unchanged. The authors considered increased AVP, potentially through reduced glomerular filtration, a possible contributor to higher vancomycin exposure.
What made this case unusual
Vancomycin trough concentration rose despite returning to the original dose, alongside an increased AVP infusion rate, while urine output remained unchanged.
Diagnostic / clinical pearl
In a child with central diabetes insipidus receiving vancomycin, consider AVP infusion-rate changes when interpreting vancomycin exposure; the authors suggest closer therapeutic drug monitoring when AVP doses are adjusted.