Does vancomycin administered at an empirical dose ensure coverage of pediatric patients against grampositive pathogens?

Objective

To investigate the vancomycin effectiveness against gram-positive pathogens with the minimum inhibitory concentration of 1mg/L in pediatric patients based on the area under the curve and the minimum inhibitory concentration ratio > 400.

Methods

A population of 22 pediatric patients (13 boys) admitted to the pediatric intensive care unit with preserved renal function was stratified in two groups (G1 < 7 years and G2 ≥ 7 years). After the fourth dose administered of vancomycin (10 - 15mg/kg every 6 hours) was administered, two blood samples were collected (third and fifth hours), followed by serum measurement by immunoassays to investigate the pharmacokinetics and antimicrobial coverage.

Results

There was no difference between the groups regarding dose, trough level or area under the curve. Coverage against gram-positive pathogens with a minimum inhibitory concentration of 1mg/L occurred in only 46% of patients in both groups. The pharmacokinetics in both groups were altered relative to the reference values, and the groups differed in regard to increased total body clearance and shortening of the biological half-life, which were more pronounced in younger patients.

Conclusion

A minimum empirical dose of 60mg/kg per day should be prescribed for pediatric patients in intensive care units with preserved renal function. The use of the ratio between the area under the curve and minimum inhibitory concentration in the evaluation of vancomycin coverage is recommended to achieve the desired outcome, since the pharmacokinetics are altered in these patients, which may impact the effectiveness of the antimicrobial.

[Study of the frequency of diabetes mellitus and glucose intolerance in patients with cystic fibrosis]

OBJECTIVE: To evaluate the frequency of diabetes mellitus and glucose intolerance in patients with cystic fibrosis treated at the Pediatric Gastroenterology Service of HC-FMRP-USP. METHODS: A cross-sectional analytical study was conducted on a group of 25 patients with mucoviscidosis who were followed up at HC-FMRP-USP. Oral glucose tolerance tests (OGTT) were performed, with simultaneous determination of glycemia and insulinemia. Areas under the curve were obtained for glycemia (G) and insulinemia (I) and the I/G ratio was calculated and correlated with the duration of clinical manifestation and pancreatic exocrine function. RESULTS: Five patients presented alterations: one was diabetic and four had glucose intolerance and/or hyperinsulinemia. There was a direct correlation between the area under the curve for insulinemia and the duration of mucoviscidosis. A significant inverse correlation was also observed between the area under the curve for insulinemia and I/G ratio, and number of enzyme capsules/kg/day. CONCLUSIONS: The frequency of alterations in glucose homeostasis observed in patients with mucoviscidosis was higher than in the population at large (20% of the total sample and 33% of the group of patients with glycemia and insulinemia on OGTT). Therefore, it is important that glucose tolerance tests be performed systematically in patients with mucoviscidosis so that metabolic abnormalities can be early detected, and proper treatment can be initiated.