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The objective of the present study was to review the available pharmacokinetic evidence for the utility of cystatin C (CysC) as a marker of renal function to predict the dose of renally excreted drugs.The bibliographic search used PubMed and EMBASE databases, from its inception through to January 2014, with the following keywords 'pharmacokinetics' and 'cystatin C'.Sixteen pharmacokinetic publications were identified and seven drugs primarily excreted by the kidney were studied. Among them, only one study was performed in children, the others were performed in adults and/or elderly subjects, either healthy volunteers or patients with variable clinical conditions, such as cystic fibrosis and cancer. Most of studies (n = 13/16) demonstrated that CysC was better correlated with clearance/trough concentration of evaluated drugs compared with creatinine.Our review supports that CysC is a good marker of renal function to predict dose of renally excreted drugs. Efforts should be made to evaluate the impact of CysC in special populations in order to define its clinical value in dosing optimization., (© 2015 The British Pharmacological Society.)

The influence of sleep restriction ( SR) during pregnancy on blood pressure and renal function among female adult offspring was investigated. Pregnant Wistar rats were distributed into control and SR groups. The SR was performed between the 14th and 20th days of pregnancy (multiple platforms method for 20 h/day). At 2 months of age, half of the offspring from both groups were subjected to an ovariectomy (ovx), and the other half underwent sham surgery. The groups were as follows: control sham (Csham), control ovx (Covx), SR sham ( SRsham), and SR ovx ( SRovx). Renal function markers and systolic blood pressure ( BPi, indirect method) were evaluated at 4, 6, and 8 months. Subsequently, the rats were euthanized, kidneys were removed, and processed for morphological analyses of glomerular area ( GA), number of glomeruli per mm3 ( NG), and kidney mass ( KM). Increased BPi was observed in the Covx, SRsham, and SRovx groups compared to Csham at all ages. Increased plasma creatinine concentration and decreased creatinine clearance were observed in the SRsham and SRovx groups compared to the Csham and Covx groups. The SRovx group showed higher BPi and reduced creatinine clearance compared to all other groups. The SRovx group showed reduced values of GA and KM, as well as increased NG, macrophage infiltration, collagen deposit, and ACE1 expression at the renal cortex. Therefore, SR during pregnancy might be an additional risk factor for developing renal dysfunction and increasing BP in female adult offspring. The absence of female hormones exacerbates the changes caused by SR. [ABSTRACT FROM AUTHOR]

Aim: We aimed to study the relationships of loop diuretic dose with renal function and clinical outcomes in patients with chronic heart failure (HF).Methods and Results: Loop diuretic dose at baseline was recorded in patients included in the Controlled Rosuvastatin Multinational Trial in Heart Failure (CORONA). The relationship to change in estimated glomerular filtration rate (eGFR) over time and to the first occurrence of the composite outcome of cardiovascular (CV) death or hospitalization owing to HF was examined in propensity score matched cohorts. Of the 5011 patients, 2550, 745, and 449 were receiving >80 mg (high), 41-80 mg (medium) and ≤40 mg (low) of loop diuretics in furosemide equivalent daily dosages, respectively, which were used to assemble 229, 385, and 1045 pairs of propensity-matched high, medium, and low dose cohorts. Compared with matched no loop diuretic groups, eGFR declined 0.3 ± 0.2, 0.3 ± 0.3 and 1.2 ± 0.5 mL/min/1.73 m(2) /year in the low-, medium-, and high-dose groups, respectively. Compared with matched no loop diuretic groups, hazard ratios (HR) (95% confidence intervals) for outcome associated with low-, medium- and high-dose groups were 1.71 (1.41-2.06), 1.99 (1.50-2.64), and 2.94 (1.95-4.41), respectively. Higher loop diuretic dose was particularly associated with increased risk for hospitalization owing to HF: HR 4.80 (2.75-8.37), P < 0.001.Conclusions: The use of loop diuretics was associated with a slightly greater rate of decline in eGFR, which did not vary significantly by diuretic dose.Loop diuretic dose was associated with higher risks of (CV) mortality and predominantly hospitalization owing to HF, which appeared to be higher among those receiving higher daily doses. [ABSTRACT FROM AUTHOR]

Aims We aimed to determine the relation between baseline systolic blood pressure (SBP), change in SBP, and worsening renal function (WRF) in acute heart failure (AHF) patients enrolled in the Pre-RELAX-AHF trial. Methods and results The Pre-RELAX-AHF study enrolled 234 patients within 16 h of admission (median 7 h) for AHF and randomized them to relaxin given intravenous (i.v.) for 48 h or placebo. Blood pressure was measured at baseline, at 3, 6, 9, 12, 24, 36, and 48 h and at 3, 4, and 5 days after enrolment. Worsening renal function was defined as a serum creatinine increase of ≥0.3 mg/dL by Day 5. Worsening renal function was found in 68 of the 225 evaluable patients (30%). Patients with WRF were older (73.5 ± 9.4 vs. 69.1 ± 10.6 years; P= 0.003), had a higher baseline SBP (147.3 ± 19.9 vs. 140.8 ± 16.7 mmHg; P= 0.01), and had a greater early drop in SBP (37.9 ± 16.0 vs. 31.4 ± 12.2 mmHg; P= 0.004). In a multivariable model, higher age, higher baseline creatinine, and a greater early drop in SBP, but not baseline SBP, remained independent predictors of WRF. Furthermore, WRF was associated with a higher Day 60 (P= 0.01), and Day 180 (P= 0.003) mortality. Conclusions Worsening renal function in hospitalized AHF patients is related to a poor clinical outcome and is predicted by a greater early drop in SBP. [ABSTRACT FROM AUTHOR]

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Pharmacokinetics and pharmacodynamics of rocuronium are well known. • A mechanistical pharmacokinetic-pharmacodynamic model based on limited data describing rocuronium and sugammadex pharmacokinetics has been published. • However, the available pharmacokinetic-pharmacodynamic model for the effects of sugammadex on rocuronium-induced neuromuscular blockade has limited predictive power. WHAT THIS STUDY ADDS • A pharmacokinetic-pharmacodynamic model is described for rocuronium and sugammadex, based on physiological principles and on data covering a wide range of ages and renal function. From this model, more accurate predictions can be made about sugammadex-mediated reversal of rocuronium-induced neuromuscular blockade, in unexplored regimens or populations. AIMS An integrated population pharmacokinetic-pharmacodynamic model was developed with the following aims: to simultaneously describe pharmacokinetic behaviour of sugammadex and rocuronium; to establish the pharmacokinetic-pharmacodynamic model for rocuronium-induced neuromuscular blockade and reversal by sugammadex; to evaluate covariate effects; and to explore, by simulation, typical covariate effects on reversal time. METHODS Data ( n= 446) from eight sugammadex clinical studies covering men, women, non-Asians, Asians, paediatrics, adults and the elderly, with various degrees of renal impairment, were used. Modelling and simulation techniques based on physiological principles were applied to capture rocuronium and sugammadex pharmacokinetics and pharmacodynamics and to identify and quantify covariate effects. RESULTS Sugammadex pharmacokinetics were affected by renal function, bodyweight and race, and rocuronium pharmacokinetics were affected by age, renal function and race. Sevoflurane potentiated rocuronium-induced neuromuscular blockade. Posterior predictive checks and bootstrapping illustrated the accuracy and robustness of the model. External validation showed concordance between observed and predicted reversal times, but interindividual variability in reversal time was pronounced. Simulated reversal times in typical adults were 0.8, 1.5 and 1.4 min upon reversal with sugammadex 16 mg kg−1 3 min after rocuronium, sugammadex 4 mg kg−1 during deep neuromuscular blockade and sugammadex 2 mg kg−1 during moderate blockade, respectively. Simulations indicated that reversal times were faster in paediatric patients and slightly slower in elderly patients compared with adults. Renal function did not affect reversal time. CONCLUSIONS Simulations of the therapeutic dosing regimens demonstrated limited impact of age, renal function and sevoflurane use, as predicted reversal time in typical subjects was always <2 min. [ABSTRACT FROM AUTHOR]

Objectives. To explore the dependence of glomerular filtration rate (GFR) on plasma total homocysteine (tHcy) and serum methylmalonic acid (MMA), as well as the consequences for the diagnosis of cobalamin and/or folic acid deficiency in an elderly community-dwelling population. Design and setting. Population-based study of 209 community-dwelling subjects, mean age 76 years. Interventions. Four months’ treatment study with oral vitamin B12, folic acid and B6 or placebo. Main outcome measures. Determinants of tHcy and MMA: cystatin C as a marker of GFR and serum/plasma concentrations of vitamin B12 and folate, age and sex. Results. Elevated cystatin C (>1.55 mg L−1) was found in 31.3% (men) and 13.0% (women). Elevated tHcy (≥16 μmol L−1) occurred in 53% and elevated MMA (≥0.34 μmol L−1) in 11% of all subjects. When GFR was taken into consideration, the proportion of elevated tHcy was reduced to 10% (20/209), whilst the proportion of elevated MMA was unchanged. Cystatin C was correlated with tHcy ( r = 0.45, P < 0.001) and with MMA ( r =0.28, P < 0.001), independently of vitamin B12- and folate status. According to multiple regression, independent predictors for tHcy were plasma folate (15%), cystatin C (11%) and vitamin B12 (4%), and for MMA, cystatin C (8%) and vitamin B12 (2%). Conclusions. The prevalence of elevated tHcy may be overestimated in elderly populations unless GFR is taken into account. Nomograms for evaluation of tHcy and MMA in relation to both cystatin C and serum creatinine are presented. [ABSTRACT FROM AUTHOR]

Abstract: Background: Glomerular filtration rate (GFR) has major prognostic implications in heart failure. Our objective was to validate the MDRD prediction equations for GFR in patients with advanced heart failure, and to compare their predictive performance to that of the Cockcroft–Gault (CG) equation. Methods: We analysed GFR in 45 patients referred for heart transplantation evaluation. 51Cr–EDTA-measured GFR was compared to GFR estimates obtained by MDRD1 and MDRD2 equations, CG equation using actual body weight, and ideal body weight. Regression analyses and Pearson correlations were performed, and Bland and Altman plots were drawn. ROC curves were obtained to illustrate each equation''s ability to predict a GFR less than 60 ml/min/1.73 m2 (moderate renal impairment). Results: Patients had a mean age of 52 years, and 69% were in NYHA class III. The mean EDTA-measured GFR was 46.9±17.2 ml/min/1.73 m2. The MDRD1 equation provided the best predictive model (narrowest limits of agreement; r =0.766, p <0.001), and the highest performance in predicting a GFR less than 60 ml/min/1.73 m2 (area under curve: 0.901). Conclusions: MDRD equations, especially MDRD1, adequately predict GFR in advanced heart failure, with higher accuracy than the CG equation. MDRD1 also has higher performance in predicting a GFR less than 60 ml/min/1.73 m2. [Copyright &y& Elsevier]

Objectives: The aim of this study was to evaluate renal function and the need for postnatal treatment--antibiotic therapy and/or surgery--in relation to the grade of fetal renal pelvic dilatation (RPD) found on third-trimester ultrasound examination. Methods: The retrospective study included 78 children, born between 1995 and 2000, with 115 dilated fetal renal pelvic units. The children were allocated to three groups based on pelvic anteroposterior diameter (APD) detected on third-trimester ultrasound: APDs of 7-9.9 mm, 10-14.9 mm and > or = 15 mm were classified as mild dilatation, moderate hydronephrosis and severe hydronephrosis, respectively. Renal function was assessed by scintigraphy. Results: None of the 20 children with mild dilatation experienced a urinary tract infection (UTI) or underwent surgery; two had associated renal or urinary tract abnormalities. In contrast, five out of 22 (23%) children with moderate hydronephrosis and 23 out of 36 (64%) with severe hydronephrosis had either a UTI or required surgery (P < 0.001); associated abnormalities were also more common (6 out of 22 and 15 out of 36, respectively). There was no significant correlation between the grade of antenatal RPD and postnatal ipsilateral renal function. Conclusions: The need for postnatal treatment increased significantly with the grade of antenatal RPD. Children with antenatal mild dilatation were discharged early from follow-up whereas those with moderate and severe fetal hydronephrosis needed close follow-up by a multidisciplinary team. [ABSTRACT FROM AUTHOR]