Chloramphenicol succinate sodium

Chloramphenicol succinate and chloramphenicol kinetics were examined on two occasions at steady state, separated by 2 to 17 days, in 10 pediatric patients on the same intravenous dose of chloramphenicol succinate. The steady-state peak serum concentration of chloramphenicol succinate fell from an average of 77.1 micrograms/ml during the first study to 42.2 micrograms/ml during the second. The steady-state peak serum concentration of chloramphenicol also decreased from an average of 27.8 micrograms/ml to 24.9 micrograms/ml. There was a marked decrease in the steady-state trough serum concentration of chloramphenicol, which averaged 8.4 micrograms/ml during the first and 5.3 micrograms/ml at the time of the second study. Mean area under the serum concentration-time curve (AUC) of chloramphenicol succinate decreased from 59.7 micrograms . hr/ml to 24.0 micrograms . hr/ml. The AUC of chloramphenicol averaged 105.7 micrograms . hr/ml at the time of the first and decreased to 79.5 micrograms . hr/ml during the second study. Mean percent decrease in the AUC of chloramphenicol was about 28% and occurred most substantially in patients with high AUCs during the first study. Mean elimination chloramphenicol half-life was 3.0 hr during the first study and fell to 2.3 hr at the time of the second study. Our data indicate that chloramphenicol serum concentration should be monitored frequently, especially in patients not responsive to a set dose.

Chloramphenicol succinate ester in doses equivalent to 25, 100 and 250 mg/kg of chloramphenicol were administered by rapid i.v. infusion in a randomized crossover fashion to five adolescent ((18-36 month) male Macaca nemestrina monkeys. Thirteen serum samples and all voided urine were collected over a 5- to 6-hr period. Urinary excretion of unhydrolyzed ester was independent of dose and averaged 26.3 +/- 6.2% of the administered dose. Dose dependency was observed for the elimination rate constant, total body clearance and metabolic clearance of chloramphenicol succinate. Dose dependency was also observed for the apparent volume of distribution, total body clearance, metabolic clearance and time to peak concentration of chloramphenicol. Although significant dose dependency of various pharmacokinetic parameters ws demonstrated, the peak chloramphenicol concentration and the elimination rate constant of chloramphenicol after administration of chloramphenicol succinate showed no significant dose-dependent changes. Therefore, peak chloramphenicol concentrations would be expected to reflect changes in dose in a linear or proportional manner.

Chloramphenicol sodium succinate (SCAP) kinetics were studied in 10 critically ill patients. High-performance liquid chromatography was used to assay SCAP and chloramphenicol (CAP) in serum and urine. Total body (ClTB), metabolic (ClM), and renal (ClR) clearances of SCAP were variable. Correlations were found between creatinine clearance (Clcr) and ClTB, ClM, and ClR of SCAP (r = 0.92, p less than 0.001; r = 0.84, p less than 0.005; and r = 0.84, p less than 0.005). Recovery of SCAP in the urine also demonstrated large interpatient variability. Between 6.5% and 43.5% of the SCAP dose was recovered in the urine of 6 patients. This variability could not be explained by incomplete urine collection or by differences in renal function. Renal excretion of SCAP was shown to influence CAP serum levels. CAP ClTB was diminished, but no relationship was found between routine liver function studies and CAP ClTB. Therefore we caution the use of such relationships in using CAP in critically ill patients.