Bacterial Infections in Children With Acute Myeloid Leukemia Receiving Ciprofloxacin Prophylaxis.

BACKGROUND: The aim of the study was to describe the incidence and type of bacterial infections associated with the use of ciprofloxacin prophylaxis as single agent in pediatric patients with acute myeloid leukemia (AML). PROCEDURE: This was a retrospective review of all patients with AML, who were treated according to the AML02 protocol between 2011 and 2015. The medical records were reviewed for any positive cultures from the initiation of the protocol until death or protocol discontinuation. Patient demographics, type of infections, type of isolated bacteria, and intensive care unit admissions were recorded. RESULTS: A total of 50 patients were evaluated, who were of a mean age of 8 years±5.1 (SD). We identified 77 episodes of bacterial infections in 42 (84%) patients. Among those bacterial infections, 73 episodes were with bacteremia and included 45 (62%) gram-positive bacterial infections, 24 (33%) gram-negative bacterial infections, and 4 (6%) mixed gram-negative and gram-positive bacterial infections. Coagulase-negative Staphylococcus and Viridans streptococci were the most commonly isolated bacteria in 33% and 30% of the episodes, respectively. Seventeen (45%) patients with bacteremia required intensive care unit admission. CONCLUSIONS: A high rate of bacterial infection was detected in patients who received the AML02 protocol, mainly gram-positive bacterial infections. The prophylactic regimen should be reconsidered for its efficacy, and other antibacterial prophylaxis may be used.

Optimizing colistin dosing: Is a loading dose necessary?

PURPOSE: Published literature on the pharmacokinetics and effectiveness of colistin loading doses is reviewed. SUMMARY: Colistin is increasingly used to treat infections caused by multidrug-resistant (MDR) gram-negative bacteria (GNB). A literature search identified seven reports on studies of colistin loading doses. All reviewed studies involved small samples of critically ill patients, with considerable variation in the colistin products and loading doses used. Pharmacokinetic studies indicated that because of the slow rate of conversion of the prodrug colistimethate sodium to the active drug colistin and the long half-life of colistin, it can take two to three days to attain adequate colistin concentrations without a loading dose. The clinical effectiveness of colistin loading doses was evaluated in two studies, neither involving the use of a comparator group. In one of those studies, clinical cure and bacteriological clearance were reported in 82.1% and 73.9% of cases, respectively; in the other, clinical resolution was reported in 77% of patients. Two studies were conducted to compare clinical outcomes of colistin loading-dose regimens and standard regimens with no loading dose; while use of a loading dose was associated with a higher cure rate (63.0% versus 41.3%, p = 0.04) in one study, no improvement in clinical outcomes was reported in the other study. CONCLUSION: Published data on the effectiveness of colistin loading doses are limited. The available evidence suggests that it may be necessary to administer a colistin loading dose in severe and life-threatening infections due to MDR GNB.