ABSTRACT
BACKGROUND: The ratio of the steady-state 24-hour area under the concentration-time curve (ssAUC24) to the MIC (AUC24/MIC) for vancomycin has been recommended as the preferred pharmacodynamic index. The aim of this study was to assess whether the calculated AUC24 (cAUC24) using the creatinine clearance (CLcr) differs from the ssAUC24 based on the individual pharmacokinetic data estimated by a commercial software. MATERIALS AND METHODS: The cAUC24 was compared with the ssAUC24 with respect to age, body mass index, and trough concentration of vancomycin and the results were expressed as median and interquartile ranges. A correlation between the cAUC24 and ssAUC24 and the trough concentration of vancomycin was evaluated. The probability of reaching an AUC24/MIC of 400 or higher was compared between the cAUC24 and ssAUC24 for different MICs of vancomycin and different daily doses by simulation in a subgroup with a trough concentration of 10 mg/L and higher. RESULTS: The cAUC24 was significantly lower than the ssAUC24 (392.38 vs. 418.32 mg.hr/L, P < 0.0001) and correlated weakly with the trough concentration (r = 0.649 vs. r = 0.964). Assuming a MIC of 1.0 mg/L, the probability of reaching the value of 400 or higher was 77.5% for the cAUC24/MIC and 100% for the ssAUC24/MIC in patients with a trough concentration of 10 mg/L and higher. If the MIC increased to 2.0 mg/L, the probability was 57.7% for the cAUC24/MIC and 71.8% for the ssAUC24/MIC at a daily vancomycin dose of 4,000 mg. CONCLUSIONS: The cAUC24 using the calculated CLcr is usually underestimated compared with the ssAUC24 based on individual pharmacokinetic data. Therefore, to obtain a more accurate AUC24, therapeutic monitoring of vancomycin rather than a simple calculation based on the CLcr should be performed, and a more accurate biomarker for renal function is needed.
Subject(s)
Humans , Area Under Curve , Body Mass Index , Creatinine , Drug Monitoring , VancomycinABSTRACT
BACKGROUND: It has been suggested that the glomerular filtration rate can be predicted on the basis of serum cystatin C concentration. The aim of this study was to investigate the clinical utility of serum cystatin C as a marker of renal function and to evaluate the effect of an initial dose of vancomycin using serum cystatin C concentration in elderly patients. MATERIALS AND METHODS: Data was collected from July 2006 to September 2008. The subjects were elderly patients (> or =60-years-of-age; n=number of patients) who had been treated with vancomycin. Serum concentrations of parameters including vancomycin, creatinine, and cystatin C were measured. Correlations between measured vancomycin concentrations and predicted vancomycin concentrations based on serum cystatin C or serum creatinine were compared, and the initial dose setting of vancomycin on the basis of serum cystatin C concentration was evaluated. RESULTS: Serum cystatin C was a good marker of renal function in comparison with serum creatinine for various doses of vancomycin in the elderly subject. In subpopulation (n=88) with normal serum cystatin C level (< or =1.2 mg/L) who were treated with routine adult vancomycin dose (1g q 12 hours), vancomycin concentration was within the therapeutic range (5-15 mg/L) in 68 patients (77.3%), and was <20 mg/L in 77 of the 88 patients (88.5 %). CONCLUSIONS: Predictive prowess of serum vancomycin concentrations on the basis of the serum cystatin C concentration could be better than that based on the serum creatinine concentration in elderly patients.
Subject(s)
Adult , Aged , Humans , Creatinine , Cystatin C , Drug Monitoring , Glomerular Filtration Rate , VancomycinABSTRACT
BACKGROUND: It has been suggested that the glomerular filtration rate can be predicted on the basis of serum cystatin C concentration. The aim of this study was to investigate the clinical utility of serum cystatin C as a marker of renal function and to evaluate the effect of an initial dose of vancomycin using serum cystatin C concentration in elderly patients. MATERIALS AND METHODS: Data was collected from July 2006 to September 2008. The subjects were elderly patients (> or =60-years-of-age; n=number of patients) who had been treated with vancomycin. Serum concentrations of parameters including vancomycin, creatinine, and cystatin C were measured. Correlations between measured vancomycin concentrations and predicted vancomycin concentrations based on serum cystatin C or serum creatinine were compared, and the initial dose setting of vancomycin on the basis of serum cystatin C concentration was evaluated. RESULTS: Serum cystatin C was a good marker of renal function in comparison with serum creatinine for various doses of vancomycin in the elderly subject. In subpopulation (n=88) with normal serum cystatin C level (< or =1.2 mg/L) who were treated with routine adult vancomycin dose (1g q 12 hours), vancomycin concentration was within the therapeutic range (5-15 mg/L) in 68 patients (77.3%), and was <20 mg/L in 77 of the 88 patients (88.5 %). CONCLUSIONS: Predictive prowess of serum vancomycin concentrations on the basis of the serum cystatin C concentration could be better than that based on the serum creatinine concentration in elderly patients.
Subject(s)
Adult , Aged , Humans , Creatinine , Cystatin C , Drug Monitoring , Glomerular Filtration Rate , VancomycinABSTRACT
It was reported that 30-50% of inpatients are in a malnutrition status. Measuring the prealbumin level is a sensitive and cost-effective method for assessing the severity of illness in critically or chronically ill patients. However it is uncertain whether or not the prealbumin level correlates with the level of nutrition support and outcomes in critically ill patients. The aim of this study was to evaluate serum prealbumin level as an indicator of the effectiveness of nutrition support and the prognosis in critically ill patients. Forty-four patients who received total parenteral nutrition for more than 7 days at an intensive care unit (ICU) were studied. The serum prealbumin was measured at the initial time of nutrition support and at the almost seventh day since the first measurement. The patients were allocated into two groups. In Group 1 (n=31) and 2 (n= 13), the prealbumin level increased and decreased, respectively. Age, APACHE II score, nutrition status, nutritional requirement and amount of supply, mortality, hospital day and ICU day in the two groups were compared. The serum prealbumin level increased in 31 out of the 44 patients. The average calorie intake was 1334 Kcal/day (83% of energy requirement) in Group 1 and 1170 kcal/day (76% of energy requirement) in Group 2 (p=0.131). The mortality was 42% in Group 1 and 54% in Group 2 (p=0.673). The average hospital day/ ICU day in Groups 1 and 2 were 80 days/38 days and 60 days/31 days respectively. In conclusion, in critically ill patients, the serum prealbumin level did not respond sensitively to nutritional support. In addition an increase in the prealbumin level dose not indicate a better prognosis for critically ill patients.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Biomarkers , Critical Illness , Malnutrition/blood , Nutrition Assessment , Prealbumin/metabolism , Prognosis , Sensitivity and SpecificityABSTRACT
BACKGROUND: We measured plasma vancomycin concentrations as a part of therapeutic drug monitoring (TDM) consultation and compared and analyzed the estimated plasma steady-state therapeutic drug levels of vancomycin obtained on the basis of measured concentrations and by population PK parameters using a PK simulation software in Korean patients to find the factors influencing the discrepancies that lie between these estimates. MATERIALS AND METHODS: We analyzed the PK parameters of the 188 patients for whom vancomycin TDM was done for 239 episodes between March, 2001 and September, 2002. The trough vancomycin plasma concentrations were measured from plasma samples that were drawn 30 minutes before a vancomycin dose. Based on the measured concentrations, we estimated the steady-state therapeutic levels (ECm) and PK parameters (apparent volumes of distribution, Vdm; clearance, Clm; and half life, T1/2m) using the single-point linear method utilized in CAPCIL (Simkin, Inc.) software program. We compared these with the steady-state levels and PK parameters estimated based on population PK database supplied by the software (ECp, Vdp, Clp, and T1/2p). We stratified and compared the values based on the patients' renal functions, body weights relative to ideal body weights, the magnitude of differences between ECm and ECp. Multiple logistic regression using SAS software package was done to analyze factors that significantly influence the discrepancies. RESULTS: One hundred and eleven were males, and 77 were females. The mean ECm were significantly lower than the mean ECp (11.9+/-9.9 microgram/ml vs. 19.2+/-19.5 microgram/ml). Clm and Vdm were higher than Clp and Vdp, respectively. The same patterns could be applied to the subclasses of patients based on renal functions and body weights. The factors that contribute to the differences in ECm and ECp were body weight, age, height, IBW, BUN, and Clcr, of which age, body weight, and BUN were found to be most significant by multiple regression analysis. CONCLUSIONS: Significant sizes of discrepancies between the estimated plasma steady-state therapeutic drug levels of vancomycin obtained on the basis of measured concentrations and by population PK parameters using a PK simulation software in Korean patients necessitate adjustment of dosage and confirmation of steady-state levels by follow-up TDM. We emphasize the need for obtaining vancomycin population PK database in Korean patients.
Subject(s)
Female , Humans , Male , Body Weight , Drug Monitoring , Follow-Up Studies , Half-Life , Ideal Body Weight , Logistic Models , Pharmacokinetics , Plasma , VancomycinABSTRACT
BACKGROUND: We measured plasma vancomycin concentrations as a part of therapeutic drug monitoring (TDM) consultation and compared and analyzed the estimated plasma steady-state therapeutic drug levels of vancomycin obtained on the basis of measured concentrations and by population PK parameters using a PK simulation software in Korean patients to find the factors influencing the discrepancies that lie between these estimates. MATERIALS AND METHODS: We analyzed the PK parameters of the 188 patients for whom vancomycin TDM was done for 239 episodes between March, 2001 and September, 2002. The trough vancomycin plasma concentrations were measured from plasma samples that were drawn 30 minutes before a vancomycin dose. Based on the measured concentrations, we estimated the steady-state therapeutic levels (ECm) and PK parameters (apparent volumes of distribution, Vdm; clearance, Clm; and half life, T1/2m) using the single-point linear method utilized in CAPCIL (Simkin, Inc.) software program. We compared these with the steady-state levels and PK parameters estimated based on population PK database supplied by the software (ECp, Vdp, Clp, and T1/2p). We stratified and compared the values based on the patients' renal functions, body weights relative to ideal body weights, the magnitude of differences between ECm and ECp. Multiple logistic regression using SAS software package was done to analyze factors that significantly influence the discrepancies. RESULTS: One hundred and eleven were males, and 77 were females. The mean ECm were significantly lower than the mean ECp (11.9+/-9.9 microgram/ml vs. 19.2+/-19.5 microgram/ml). Clm and Vdm were higher than Clp and Vdp, respectively. The same patterns could be applied to the subclasses of patients based on renal functions and body weights. The factors that contribute to the differences in ECm and ECp were body weight, age, height, IBW, BUN, and Clcr, of which age, body weight, and BUN were found to be most significant by multiple regression analysis. CONCLUSIONS: Significant sizes of discrepancies between the estimated plasma steady-state therapeutic drug levels of vancomycin obtained on the basis of measured concentrations and by population PK parameters using a PK simulation software in Korean patients necessitate adjustment of dosage and confirmation of steady-state levels by follow-up TDM. We emphasize the need for obtaining vancomycin population PK database in Korean patients.
Subject(s)
Female , Humans , Male , Body Weight , Drug Monitoring , Follow-Up Studies , Half-Life , Ideal Body Weight , Logistic Models , Pharmacokinetics , Plasma , VancomycinABSTRACT
This report supports interactions between phenytoin and both enteral feeding products and nasogastric feeding tube. Five patients in ICU were treated with intravenous phenytoin, which yield detectable therapeutic serum concentrations. After switching to a comparable phenytoin capsule administered by nasogastric feeding tube, their serum phenytoin concentration fell to below assay sensitivity concentrations. Two of them experienced seizures. They were administered by intravenous phenytoin again or another antiepileptic drug, so the seizures were controlled. Some fact of decreased phenytoin absorption in enteral feeding patients is that phenytoin interact enteral feeding product and adhere the nasogastric feeding tube itself. We conclude that it is necessary to use phenytoin with caution in enteral feeding patients.
Subject(s)
Humans , Absorption , Enteral Nutrition , Phenytoin , SeizuresABSTRACT
The adverse drug reaction(ADR) monitoring is very critical in healthcare. However, the number of actual reported cases on ADR has been extremely low in Korea compared to other countries. This study was designed to find out a way to expedite ADR reporting in a general hospital, where many drugs are used daily. In this study, a newly developed ADR monitoring system has been implemented and was evaluated for its outcome. In addition, a survey was conducted for two groups, 50 ADR reporters and 100 non-reporters, to identify factors which can affect the ADR reporting. The new system was a multidisciplinary program based on a voluntary reporting involving doctors, nurses and pharmacists. The reporting methods were diversified such as ADR report sheet, computerized Order Communication System(OCS) consultation and drug refund reports. After a year since the system has been implemented, the number of reported cases was 158, which was 131 times higher than that of the pre-implementation period. Doctors reported the most(75 .3%), and ADR report sheet was used most frequently(57%). In terms of severity of ADR 74.7% was mild, 22.8% moderate and 2.5% severe. The unexpected ADRs were 7.6%. Both groups had a high degree of awareness of the necessity of monitoring and basic knowledge of ADR. Important factors affecting ADR reporting were frequency of ADR findings(p<0.01), awareness of the fact that the institution was designated as an ADR monitoring institution(p<0.001) and participation in the education program(p<0.01). In conclusion, modification of the reporting system and ongoing and systematic education are needed to improve ADR monitoring in a general hospital.