ro13-9904 and Uremia

The disposition profile of ceftriaxone was studied in 12 functionally anephric patients (creatinine clearance less than 10 ml/min) who received bolus injections of 150, 500, and 1500 mg IV in a noncrossover fashion. As in healthy subjects, the kinetics in uremic patients were nonlinear for total (bound plus unbound) and linear for free (unbound) drug. The plasma protein binding was reduced due to a decreased association constant, resulting in a doubling of the free fraction in plasma. Ten of 12 patients showed nonrenal clearance values of unbound drug (ClFNR) identical to those in healthy adults and only minor increases in their biologic t1/2(beta) compared to normal (12 and 8 hr). These patients would require no dose adjustments in their dosing regimen. Two of the patients exhibited decreased ClFNR values and increased t1/2(alpha) of 20 and 34 hr. Anephric patients with impaired nonrenal elimination would require minor dose adjustments.

Topics: Adult; Aged; Cefotaxime; Ceftriaxone; Chromatography, High Pressure Liquid; Clinical Trials as Topic; Creatinine; Dose-Response Relationship, Drug; Female; Half-Life; Humans; Kidney; Kinetics; Male; Metabolic Clearance Rate; Middle Aged; Protein Binding; Uremia

The temporal relationship between convulsive seizures and the administration of beta-lactams has long been recognized. A specific form of seizures, nonconvulsive status epilepticus, is less common and is often manifested by alterations in mental status without associated seizures. It is most commonly encountered in uremic patients and poses a diagnostic challenge because of its nonspecific clinical manifestations. In this report, we describe a child with chronic renal failure who developed nonconvulsive status epilepticus on two separate occasions after administration of a third-generation cephalosporin. Awareness of this potentially treatable condition is crucial to ensure appropriate and prompt medical therapy. To our knowledge, this is the first report of cephalosporin-induced nonconvulsive status epilepticus in a child with chronic renal failure.

Topics: Ceftriaxone; Cephalosporins; Child; Female; Humans; Status Epilepticus; Uremia

Ceftriaxone is a third-generation cephalosporin exhibiting a long half-life and a concentration-dependent protein binding. This study compared three techniques of protein binding determination (equilibrium dialysis chamber, ultrafiltration cones (Centriflo), and ultrafiltration (Centrifree micro-partition system) on human plasma and serum at ceftriaxone concentrations achieved clinically. A second objective was to determine the effect of 2-hydroxybenzoylglycine (HBG) on the protein binding of ceftriaxone. High performance liquid chromatography (HPLC) and liquid scintillation counting assays were used. Equilibrium dialysis was rotated for 12 h. The supplier's recommendations were followed for ultrafiltration techniques. The plasma protein binding of ceftriaxone, as determined by equilibrium dialysis and assayed by HPLC, decreased from 98.6 to 73.5% for drug concentrations varying from 25 to 400 micrograms/ml. Somewhat lower values were obtained with Centrifree, the binding fell from 92.1 to 73.5% for the same concentration range. Serum protein binding was similar to results obtained with plasma samples. Centriflo cones yielded more inconsistent results. A significant difference was seen between the three techniques (p less than 0.0001, three-way analysis of variance). The addition of HBG, a compound that inhibits drug binding in uremia, resulted in ceftriaxone binding defects similar to those seen in uremic serum. Although equilibrium dialysis remains a classic method of protein binding determination, Centrifree appears to be a better system.

Topics: Adolescent; Adsorption; Adult; Ceftriaxone; Chromatography, High Pressure Liquid; Dialysis; Female; Hippurates; Humans; Hydrogen-Ion Concentration; Kidney Diseases; Male; Protein Binding; Ultrafiltration; Uremia

Guidelines presented previously for the analysis of plasma concentration versus time data for a drug exhibiting concentration-dependent plasma protein binding were successfully applied to the distributional parameters of a new cephalosporin, ceftriaxone. This approach provided several striking observations when the pharmacokinetics of ceftriaxone in a healthy and uremic population were re-examined. First, the parameter -fp converted the apparent dose-dependent distributional terms of ceftriaxone into a function of the concentration-dependent plasma protein binding. Second, a strong correlation between the term VUSS and the reciprocal of -fp was established within each of the two populations. While this -fp term accounted for the variability within the respective populations due to ceftriaxone-albumin binding differences, it did not account for all of the distributional differences between the two populations. The present analysis revealed that the altered physiologic state of uremia (larger plasma volumes and interstitial to intravascular albumin ratios), in addition to differences in plasma protein binding, dictated the distribution of ceftriaxone in healthy and uremic subjects. Furthermore, the binding-disposition model which accounts for the presence of plasma proteins outside the vascular space, was established to be appropriate in describing the distribution of ceftriaxone.

Topics: Blood Proteins; Cefotaxime; Ceftriaxone; Dose-Response Relationship, Drug; Female; Humans; Kinetics; Male; Mathematics; Models, Biological; Protein Binding; Uremia