Pharmacotherapy
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Comparative Study
QT interval prolongation and torsades de pointes due to erythromycin lactobionate.
To discern the frequency of torsades de pointes and QT prolongation in patients receiving intravenous erythromycin lactobionate; to examine the degree of QT prolongation and QT dispersion due to intravenous erythromycin in a typical clinical setting; and to identify any concurrent factors that might predispose patients to excessive QT prolongation or torsades de pointes while receiving intravenous erythromycin. ⋯ Erythromycin lactobionate-induced torsades de pointes is rare, although QT prolongation is common. Some patients may be at risk for suffering torsades de pointes due to this agent, particularly if heart disease or other factors that may further delay ventricular repolarization are present.
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Comparative Study Clinical Trial Controlled Clinical Trial
The effects of age and chemotherapy on gentamicin pharmacokinetics and dosing in pediatric oncology patients.
We attempted to determine the effects of prior antineoplastic chemotherapy and age on gentamicin pharmacokinetics in children (age 1-18 yrs) with cancer and in controls, and to establish a protocol for gentamicin dosing and monitoring to ensure rapid attainment of therapeutic serum concentrations in these patients. In a prospective controlled study, patients with fever who were receiving empiric gentamicin for confirmed or suspected infections were separated into three groups: 29 with cancer who were receiving a continuing chemotherapy protocol with nonnephrotoxic antineoplastic agents; 23 with cancer who were receiving a continuing chemotherapy protocol with nephrotoxic antineoplastic agents; and 25 control patients who did not have cancer. Three blood samples (one predose, two postdose concentrations), collected between the third and sixth gentamicin doses from each patient, were analyzed by the Emit assay. ⋯ However, when normalized by body surface area, the age-dependent doses became remarkably similar for children in all three age groups (ANOVA p = 0.932), approximately 250 mg/m2/day. We recommend that pediatric patients with cancer who require treatment for fever and neutropenia be given higher than standard gentamicin dosages to achieve therapeutic serum concentrations promptly. In particular, initial empiric doses of 10 mg/kg/day are appropriate for those age 1-5 years.