Recommended intraperitoneal vancomycin dosing seen as too high for children with PD-associated peritonitis

DALLAS — The current recommended dosing of intraperitoneal vancomycin for PD- associated peritonitis, as indicated by the International Society for Peritoneal Dialysis, may be too high for children and may cause elevated vancomycin levels, according to findings presented at the Annual Dialysis Conference.

“When dosing intraperitoneal vancomycin, the current ISPD guidelines recommend a loading dose of 1,000 mg/L with a dwell time of 3 to 6 hours and a maintenance dose of 25 mg/L,” Nadine Benador, MD, of the University of California and Rady Children’s Hospital in San Diego, and colleagues wrote in a poster presentation. “Recent observations at Rady Children’s Hospital indicate that the loading dose may be too high, causing elevated serum vancomycin levels and potential toxicity in our pediatric patients.”

To determine if this recommended loading dose was responsible for elevated vancomycin levels in children on PD, researchers conducted a retrospective review of all patients aged between 2 months and 18 years and who were treated with intraperitoneal vancomycin for PD-associated peritonitis at Rady Children’s Hospital San Diego between January 2013 and April 2017 (n = 5). To obtain serum vancomycin levels, researchers used EPIC electronic medical records. Three patients (aged 3, 4 and 16 years old) were identified with a total of six peritonitis episodes.

Of these, two episodes were treated with 1,000 mg/L of intraperitoneal vancomycin.

For these episodes, researchers found that the first vancomycin levels after receiving the first loading dose were 95.6 mg/mL and 49 mg/mL. Following a dosing of 500 mg/L, vancomycin levels were 33.2 mg/mL, 30.2 mg/mL, 23.6 mg/mL and 22.1 mg/mL.

A 1,000-mg/L intraperitoneal vancomycin loading dose led to an estimated peak vancomycin level of more than 50 mg/ml in patients who weighed 15 kg to 35 kg and an estimated peak level of more than 60 mg/L in patients who weighed less than 15 kg, according to the researchers.

Furthermore, researchers determined that vancomycin levels will remain above 20 mg/L for more than 2 days with no additional vancomycin dosing.

“The data suggests that, in pediatric patients, a loading dose of vancomycin 1,000 mg/L in dialysate leads to higher than desired vancomycin levels and should be lowered [and that] excessive exposure of vancomycin is most likely seen in younger children,” the researchers wrote. “A recommended dose in pediatric patients of 500 mg/L appears appropriate, but further studies must be done.” – by Melissa J. Webb

Reference:

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Benador N, et al. IP Vancomycin dosing for PD-associated peritonitis: Should the guidelines be changed? Presented at the Annual Dialysis Conference; March 16-19, 2018; Dallas.

Disclosure: Healio/Nephrology was unable to confirm relevant financial disclosures prior to publication.