Assessment of pharmacokinetic mycophenolic acid clearance models using Monte Carlo numerical analysis.

Previously, we performed population pharmacokinetic analysis and indicated age, mycophenolate mofetil (MMF)/mycophenolic acid (MPA) daily dose, and presence of nifedipine in patient therapy as significant predictors of MPA apparent clearance (CL/F) variability. This study aimed to determine the reliability of previously published population pharmacokinetic models derived from similar studies. Furthermore, this study investigated correspondence between chosen population models from the literature.By means of the Monte Carlo simulation method, pharmacokinetic models from different studies are simulated and analysed in the range of standard deviations of measured system parameters as well as the range of observed model parameters taken from the comparison studies.The 1000 numerical simulations were performed for every analysed model in order to calculate the most possible MPA CL/F values according to the expected values from the performed experiment. Fitting our results with other models showed how the presence of nifedipine makes difference in MPA CL/F values.By testing the data from selected studies into our model, a similar range of expected CL/F values was obtained, which may confirm the validity of our model. The results of our population pharmacokinetic study are partially applicable in models by other researchers.

The significant role of dietary intake of vitamin D in non-menopausal women health.

Optimal vitamin D status is very important for reflecting not only bone but overall woman's health. The aim of the study was to determine pharmacokinetic variability of 25-hydroxy vitamin D, to reveal and quantify the most significant factors that affect its variability in the population of healthy non-menopausal women using the population pharmacokinetic (PopPK) approach. The study population consisted of 74 healthy reproductive women aged from 35 to 50 years, without the use of any supplement. A population pharmacokinetics analysis was conducted using a nonlinear mixed-effects model software. A total of 35 factors were assessed: demographic, clinical, biochemical data and lifestyle factors. The average age and bodyweight of our participants were 40.11 ± 4.35 years 65.30 ± 6.80 kg, respectively. The observed mean serum concentration of 25-hydroxy vitamin D was 26.51 ± 13.49 ng/mL with a wide range of 6.97 to 59.89 ng/mL. Development final PopPK model of the clearance of 25-hydroxy vitamin D showed that only the average daily dose of vitamin D intake from food had a significant influence, with a magnitude of its effects of 0.00401. These results could help when individualizing vitamin D intake in the form of supplements, especially during the wintertime, in healthy reproductive women.

Chokeberry juice supplementation in type 2 diabetic patients - impact on health status.

Recent literature evidence indicates the potential use of chokeberry preparations in the prevention and treatment of some chronic noncommunicable diseases. The aim of the present study was to evaluate the effects of the three months oral chokeberry juice supplementation in type 2 diabetic patients, as well as its influence on hematological parameters and certain parameters of the renal dysfunction. The study was designed as an open-label trial, which included 35 patients who have received the herbal supplement, polyphenol-rich chokeberry juice (150 ml/day, three times a day for 50 ml), in addition to their standard therapy. Chokeberry juice as a rich source of polyphenol compounds could be an effective preventive and therapeutic agent in diabetes mellitus type 2. Hematological and biochemical parameters were measured at baseline, after 3 months with the chokeberry juice supplementation and after the next 3 months without the chokeberry juice supplementation (follow-up period). Significant difference was noticed in the levels of LDL-cholesterol, glycated hemoglobin and serum creatinine (p < 0.05), as well as in the levels of some hematological parameters, such as white blood cell and lymphocyte count (p < 0.01), hematocrit, blood hemoglobin, mean corpuscular volume, hemoglobin and hemoglobin concentration and red blood cell count (p < 0.05). The daily consumption of the chokeberry juice could improve the health status in patients with type 2 diabetes mellitus, in combination with their standard therapy.

Potentially inappropriate prescribing of drugs in elderly patients on chronic hemodialysis treatment
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PURPOSE: The aim of this study was to determine the prevalence of potentially inappropriate drug prescription (PIP) in older patients who were on chronic hemodialysis treatment and to explore the factors that lead to PIP. MATERIALS AND METHODS: The study was performed at the Department of Nephrology, Clinical Center Nis, Serbia. It included patients who were 65 years old and older who suffered from the end-stage of kidney failure and were treated by hemodialysis. Univariate and subsequent multivariate logistic regression was used to analyze risk factors for PIP or omission (PPO) according to the STOPP and START criteria. RESULTS: The study included 83 patients. According to the START criteria, PPO was found in 18 (22%) patients, and 32 (39%) patients experienced PIPs according to the STOPP criteria. The following factors were associated with PIP according to the START criteria: a number of comorbidities, reading the patient leaflet, and having the habit of drinking coffee. According to the STOPP criteria, polypharmacy was associated with PIP (OR = 1.287, p = 0.021): each additional drug increased the risk of potentially inadequate medications (PIM) by 28.7%. CONCLUSION: Adequate consideration of potential risk factors, as well as the implementation of valid criteria for assessment of PIP, are just some of the measures that would contribute to solving complex therapeutic problems and designing strategies for rational prescribing according to the individual characteristics of patients.
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Renalase Assessment With Regard to Kidney Function, Lipid Disturbances, and Endothelial Dysfunction Parameters in Stable Renal Transplant Recipients.

BACKGROUND: Renal transplant dysfunction has been shown to be independent predictor for premature cardiovascular disease and mortality. Renalase, a flavoprotein secreted by several tissues, including the kidney, has been found to regulate sympathetic tone and blood pressure. The purpose of this secondary analysis was to explore relationships among parameters of endothelial dysfunction, lipids, glomerular filtration rate, and renalase in 2 groups: renal transplant patients with controlled hypertension and healthy volunteers. METHODS: In the parent study, 73 renal transplant recipients and 32 age- and gender-matched controls were enrolled. A fasting sample for endothelial, lipid, and renalase values, along with other clinical parameters, was obtained. RESULTS: We found statistically significant inverse correlation between renalase and estimated glomerular filtration rate ( r = -0.552, P < .001), positive correlation between renalase and creatinine ( r = 0.364, P = .003), total cholesterol ( r = 0.578, P < .001), low-density lipoprotein cholesterol ( r = 0.261, P = .046), and non-high-density lipoprotein cholesterol ( r = 0.327, P = .01). Renalase inversely correlated with hemoglobin ( r = -0.232, P = .032) and positively with white blood cells ( r = 0.233, P = .032). There was a significant difference in plasma renalase with regard to chronic kidney disease stages ( F = 13.346, P < .001) but did not correlate with C-reactive protein. Renalase did not correlate with any of parameters of endothelial dysfunction, C-reactive protein, neither with some demographic data (gender, age, time or type of transplantation, risk factors). There were no differences in renalase concentration with regard to antihypertensive therapy. CONCLUSION: Renalase strongly and inversely correlated with kidney function, positively with creatinine and lipid disturbances. Due to that it is very likely that renalase levels are determined mostly by renal function.

Variability of mycophenolic acid elimination in the renal transplant recipients ­ population pharmacokinetic approach.

The aim of this study was to develop a population pharmacokinetic (PK) model for clearance of mycophenolic acid (MPA) in adult renal transplant recipients, to quantify the PK parameters and the influence of covariates on the MPA pharmacokinetic parameters. Parameters associated with plasma concentrations of MPA at steady-state were analyzed in 70 renal transplant recipients (mean age 42.97 years; mean total body weight 75.33 kg) using nonlinear mixed-effect modeling (NONMEM). Characteristics of patients screened for influence on the pharmacokinetic parameters were gender, age, body weight, time after transplantation, whether the patient was diagnosed as having diabetes mellitus, organ source (living or deceased donor), biochemical parameters and co-therapy (tacrolimus, cyclosporine, prednisolone, omeprazole, bisoprolol, carvedilol, nifedipine). A validation set of 25 renal transplant recipients was used to estimate the predictive performance of population pharmacokinetic model. Typical mean value of MPA oral clearance, estimated by base model (without covariates) was 0.741 L h(-1). During population modeling, the full model showed that clearance of the MPA was significantly influenced by age, total daily dose of MPA, creatinine clearance, albumin level, status and gender of a donor, and the nifedipine and tacrolimus co-therapy. In the final model, clearance of MPA was reported to be significantly influenced by age, total daily dose of MPA and thenifedipine co-therapy. The derived model describes adequately MPA clearance in terms of characteristics of our patients, offering basis for individual pharmacotherapy approach.

Gender-dependent predictable pharmacokinetic method for tacrolimus exposure monitoring in kidney transplant patients.

Tacrolimus (Tac) is an immunosuppressive drug with a narrow therapeutic width and highly variable pharmacokinetics. Therefore, monitoring of Tac blood concentrations is of utmost importance in the management of renal transplant recipients. The occurrence and intensity of adverse effects depend on blood concentration and total exposure of the organism to this drug. This implies finding a new gender-dependent predictable method for Tac exposure monitoring based on determination of the area under the time concentration curve (AUC). The primary aim of this study was to investigate gender differences in systemic body exposure to Tac in renal transplant patients after the first oral dose and in a steady state by determining 12-h AUC (AUC(0-12)). The secondary objective was to find the best sampling time in which measured Tac concentration best predicts AUC value with respect to gender. Tac pharmacokinetic study was conducted in 20 kidney transplant recipients (10 men/10 women) on quaternary immunosuppressive therapy. The first oral Tac dose (0.05 mg/kg) was given on the fifth day post-transplant. After reaching steady state, regimen stabilized and dosage was adjusted in accordance with the level of Tac. Blood concentrations were measured by microparticle enzyme immunoassay method. AUC(0-12) for each patient was calculated after the first oral Tac dose and in the steady state from a plot of Tac concentration versus time from 0 to 12 h using the trapezoid rule. Associations between each sampling time point of concentrations within 12 h after the administration and AUC(0-12) were evaluated by Pearson correlation coefficients. Abbreviated sampling equations were derived by multiple stepwise regression analyses. Statistically significant difference was found in AUC(0-12) between male and female patients after the first oral dose (p < 0.01), but this difference was lost in a steady state. In female recipients C(2) seemed to be good indicator of total body exposure to Tac after the first oral dose and this was also confirmed in a steady state. The three-point sampling method was required for calculating AUC after the first oral dose in male patients, whereas in the steady state, concentration of C(8) seemed to be a good indicator of abbreviated AUC for a Tac monitoring strategy in male patients. Non-compartment Tac pharmacokinetic and regression analysis showed gender difference in total Tac exposure and determined the best predictable Tac concentrations after the first oral dose. Our study confirmed gender-dependent pharmacokinetics in a steady state in terms of best sampling time in which measured Tac concentration best predicts AUC value.

Immunosuppressive medication adherence in kidney transplant patients.

OBJECTIVES: To assess the degree of immunosuppressive medication adherence in kidney transplant patients (KTPs) and to determine if there is a difference in the rate of adherence to tacrolimus (Tac), cyclosporine (CsA) and sirolimus (Sir). SUBJECTS AND METHODS: From a total of 63 KTPs treated at the Clinic of Nephrology, Clinical Centre Nis, Serbia, 60 participated in the study by responding to questionnaires. They were divided into the adherence group (n = 43) and the nonadherence group (n = 17) according to their degree of adherence which was measured using a validated survey form, the simplified medication adherence questionnaire. The KTP adherence to the different immunosuppressive regimens (Tac, CsA and Sir) was compared. Statistical analysis was performed using the Student t test. RESULTS: Adherence was observed in 43 (71.7%) patients, and only 17 (28.3%) did not follow the prescribed therapy. The estimated glomerular filtration rate was significantly lower in the nonadherence group (38.52 ± 18.22 ml/min) than in the adherence group (52.43 ± 16.91 ml/min, p < 0.05). With regard to the Tac level, a significant difference was also found between the adherers and the nonadherers (6.30 ± 2.06 vs. 5.0 ± 1.52 ng/ml, p < 0.05). CONCLUSION: The KTPs in this study demonstrated a high level of adherence. Nonadherence was associated with worse graft function and a lower Tac level. Knowledge about the degree of adherence could help the early identification of nonadherent patients and the development of strategies to improve this.

The Impact of Opioid Receptor Gene Polymorphism on Fentanyl and Alfentanil's Analgesic Effects in the Pediatric Perioperative Period.

Introduction: The polymorphism of the gene coding mu-opioid receptor (OPRM1) is one of the factors contributing to the variability in the response to opioid analgesics in children. The goal of this study is to investigate its role in association with postoperative acute pain in children of various ages. Methods: This prospective study analyzed 110 pediatric patients, after plastic or orthopedic surgery, who were genotyped and randomly assigned to receive fentanyl or alfentanil. Postoperative pain was rated using Numerical Rating Scale (0-10). All the patients were genotyped forOPRM1 118A>G (rs1799971) gene polymorphism. Results: School children under the age of 11 with the OPRM1 AA genotype were shown to have a higher BMI (p<0.05). Children over the age of 12 carrying G allele OPRM1, had increased postoperative pain sensitivity and intensity (3.28±1.95 vs 4.91±2.17; p<0.05), as compared to AA allele carriers. Discussion: OPRM1 118A>G polymorphism may explain the variation in the perception of postoperative pain in children over the age of 12 and may be a useful predictor for adjusting the dose of analgesics, but the dose is relative to the patient's needs regardless of his genetic characteristics. In younger children, carriers of polymorphic OPRM1 118G allele may be protected from obesity, due to diminished MOP expression.

Impact of IL-6 and IL-10 genotypes on tacrolimus dose requirements in kidney transplant recipients: Monte Carlo analysis.

Introduction: IL-6 and IL-10 may affect the activity of cytochrome P450 (CYP) 3A enzymes involved in tacrolimus (Tac) metabolism. Moreover, the effect of IL-6 and IL-10 on Tac pharmacokinetics may differ with respect to the genetic variations in their genes.Aim: To examine the influence of IL-6 and IL-10 gene polymorphisms on Tac dose requirements and exposure over a 5-year period following kidney transplantation. Univariate and standard multivariate linear regression and Monte Carlo analysis were performed to investigate potential covariates influencing Tac dose-adjusted trough concentration (C0/D) in various post-transplantation periods.Materials & methods: IL-6 (-174G > C), IL-10 (-1082G > A, -819C > T and -592C > A) genotype, Tac daily dose, C0, C0/D and intrapatient variability data were collected from 113 patients.Results: Multivariate regression analysis and accompanied Monte Carlo simulation underscore the importance of considering IL-6 -174G > C and IL-10 -1082G > A gene polymorphisms, alongside Tac metabolic phenotype and post-transplantation period, when tailoring Tac dosage regimen.Conclusion: This study provides valuable insights regarding the individualized adjustment of Tac treatment in various post-transplantation periods.

[Box: see text].

Population pharmacokinetics of bisoprolol in patients with chronic heart failure.

PURPOSE: The aim of the study was to develop a population pharmacokinetic (PK) model for clearance of bisoprolol in patients with congestive heart failure (CHF). METHODS: Parameters associated with the plasma concentrations of bisoprolol at steady-state were analyzed in 61 patients (mean age 66.21 ± 9.49 years; mean total body weight 8.90 ± 12.26 kg) with CHF using non-linear mixed-effect modeling (NONMEM). A validation set of 17 patients with heart failure was used to estimate the predictive performance of the pharmacokinetic model. RESULTS: The typical mean value for bisoprolol clearance (CL), estimated by the base model (without covariates), in our population was 11.4 l h(-1). In the full model, covariates such as bisoprolol total daily dose (DD) and creatinine clearance were included. The final regression model for the clearance of bisoprolol was the following: CL (l h(-1)) = 4.68 + 0.859 * DD. CONCLUSION: The derived PK model describes the clearance of bisoprolol in patients with CHF, showing that the total daily dose of bisoprolol is the most important covariate. This finding will provide the basis for future PK studies on beta blockers in this specific patient population and lead to better overall management of heart failure.

How the duration period of erythropoietin treatment influences the oxidative status of hemodialysis patients.

BACKGROUND: End-stage renal disease is a state of enhanced oxidative stress (OS) and hemodialysis (HD) and renal anemia further augment this disbalance. Anemia correction with erythropoietin (EPO) may improve oxidative status. However, there is no evidence of time dependent effects of EPO therapy on redox status of HD patients. OBJECTIVE: The aim of this study was to evaluate whether the duration of EPO treatment may affect OS parameters in uremic patients. PATIENTS AND METHODS: 104 HD patients and 29 healthy volunteers were included. Patients were divided into 3 groups according to the duration of EPO treatment. Forth group consisted of HD patients without EPO treatment. Plasma and erythrocyte malondialdehyde (MDA, MDA(rbc)), reactive carbonyl groups (RCG), plasma sulfhydryl (-SH) groups and total antioxidative capacity (TAC) levels were evaluated. RESULTS: HD patients both with and without EPO treatment, showed a significant increase in all oxidative parameters without significance between EPO treated and -untreated group. The decrease in MDA and MDA(rbc) levels coincided with the duration of EPO treatment. A negative correlation was observed between the duration of EPO treatment and serum MDA (r=-0.309, p=0.003). Increasing periods of EPO treatment were associated with decrease in RCG, without significance between EPO groups. Increase in TAC accompanied increasing durations of EPO treatment, with EPO treatment for more than 24 months causing the most striking changes (p<0.05). There were no significant differences in -SH levels between EPO subgroups. CONCLUSION: Our results suggest that long term administration of EPO attenuated the lipid peroxidation process and restored the levels of antioxidants.

Antibiotic utility and susceptibility changes of multidrug-resistant Escherichia coli and Klebsiella spp: 5-year experience in a tertiary healthcare centre.

OBJECTIVES: Multiple studies have identified cross-sectional relationships between antibiotic use and bacterial resistance. The aim of this study was to analyse the susceptibility of multidrug-resistant (MDR) and non-MDR (nMDR) isolates of Escherichia coli and Klebsiella spp to cephalosporins: ceftazidime (CTZ), ceftriaxone (CTX), cefepime (CEF) and fluoroquinolones: ciprofloxacin (CIP) and levofloxacin (LEV) in a tertiary healthcare centre from 2014 to 2018. In addition, we aimed to evaluate a correlation between the antibiotic utility and susceptibility of the selected enterobacteria. METHODS: Antibiotics consumption and antimicrobial resistance were monitored in a tertiary care university hospital from 2014 to 2018. Utilisation of antibiotics in the observed period was expressed as defined daily dose (DDD) per 100 bed/days (DBD). Bacterial susceptibility was reported as the percentage of susceptible results among all tested isolates from all patient samples. In further analysis, bacterial strains were considered as MDR or nMDR species. An MDR bacterial strain was defined as one with acquired non-susceptibility to at least one agent in three or more antimicrobial categories. RESULTS: Our results suggest that cephalosporins were the most used antibiotics, followed by fluoroquinolones, during the entire observed period 2014-2018. Our findings show that MDR isolates of E. coli had an increasing trend in susceptibility in relation to CTX (p=0.005), whereas a decreasing trend was observed for MDR isolates of E. coli susceptibility towards CIP and LEV (p<0.001). Klebsiella spp susceptibility for MDR isolates showed a decreasing trend in relation to CEF (p<0.001) and both fluoroquinolones (p<0.001). A significant negative association between CEF consumption and Klebsiella spp MDR isolates susceptibility was observed (p=0.045). CONCLUSION: Implementation of antimicrobial stewardship programmes with early detection and close monitoring of MDR bacterial strains of E. coli and Klebsiella spp may be a crucial step in reducing the menace of antimicrobial resistance, which is now a global problem.

Utility of salivary mycophenolic acid concentration monitoring: Modeling and Monte Carlo validation approach.

The results of the previous studies demonstrated an association between mycophenolic acid (MPA) exposure, serum albumin level (ALB), and adverse effects in kidney transplant patients. The aim was the identification of mathematical correlation and association between both, total and unbound MPA concentration in relation to ALB, body mass (BM), age and estimated glomerular filtration rate (eGFR) in stable kidney transplant recipients. Furthermore, investigation was conducted with the aim to clarify the role of salivary concentration (CSAL ) of MPA in adverse effect profile. In order to analyze the association between total and salivary concentration of MPA in relation to ALB, BM, age and eGFR, a least squares method for determining the correlation between these parameters was performed. In addition, derived mathematical model based on experimental data can also be performed and simulated through the Monte Carlo (MC) approach. Adverse effects were grouped according to the nature of symptoms and scored by a previously published validated system. Numerically calculated values of CSAL from the models [CSAL  = f(ALB, BM, age, eGFR, CP ) = a00 + a10 *(ALB, BM, age, eGFR) + a01 *CP ] were then compared with those from validation set of patients, where the best fitting model was for ALB [CSAL  = 54.96-1.64*ALB +13.4*CP ]. Adverse effects estimation showed the difference in esthetic score, positively correlated with CSAL in the lower ALB group (145.41 ± 219.02 vs. 354.08 ± 262.19; with statistical significance p = .014) and almost significant for gastrointestinal score (167.69 ± 174.79 vs. 347.55 ± 320.95; p = .247). The study showed that CSAL MPA may contribute to management of adverse effects, but these findings require confirmation of clinical utility.

Effect of the Interrelation between CYP3A5 Genotype, Concentration/Dose Ratio and Intrapatient Variability of Tacrolimus on Kidney Graft Function: Monte Carlo Simulation Approach.

Background: Tacrolimus (Tac) is characterized by large between- and within-patient (IPV) variability in pharmacokinetics and exposure. Aim: This study aimed to assess and validate the effect of Tac IPV and trough concentration-to-dose ratio (C0/D) over 6-12 months on reduced estimated glomerular filtration rate (eGFR) values in the late period after kidney transplantation (Tx), applying Monte Carlo (MC) simulation. Methods: The previously published linear regression was the basis for MC simulation, performed to determine how variations in significant predictors affect the distribution of eGFR from 13 to 36 months post-transplantation. The input C0/D values were derived from CYP3A5 genotype subgroups. Results: Patients characterized by high Tac IPV and low mean C0/D over 6-12 months could have been at greater risk of lower eGFR values in a three-year period following Tx compared to the other patient groups. This effect was more pronounced in patients with a lower eGFR at the 6th month and a history of acute rejection. The proven contribution of CYP3A5 expresser genotype to low C0/D values may suggest its indirect effect on long-term graft function. Conclusion: The findings indicate that simultaneous assessment of Tac IPV, C0/D, and CYP3A5 genotype may identify patients at risk of deterioration of graft function in the long-term post-transplantation period.

Combined Effect of Inter- and Intrapatient Variability in Tacrolimus Exposure on Graft Impairment Within a 3-Year Period Following Kidney Transplantation: A Single-Center Experience.

BACKGROUND AND OBJECTIVE: Tacrolimus is a cornerstone of the most immunosuppressive protocols after kidney transplantation, but its use is complicated by notable interpatient and intrapatient variability (IPV). The goal of this study was to evaluate whether or not tacrolimus IPV, or average dose-adjusted trough concentration (C0/D), during 6-12 months post-transplantation might have contributed to graft function decline in a 3-year period following kidney transplantation. After primary evaluation of individual effects of tacrolimus IPV and C0/D, the study aimed to estimate the combined effect of tacrolimus IPV and C0/D on composite endpoint (consisting of graft failure, chronic allograft dysfunction, chronic rejection, and doubling of serum creatinine concentration) in the period between 13 and 36 months after kidney transplantation. In addition, the goal was to analyze the impact of genetics on interpatient variability in tacrolimus exposure in the early and late post-transplantation periods. METHODS: The study enrolled 104 Caucasian patients and included 2541 patient examinations up to 36 months after kidney transplantation. All patients were genotyped on CYP3A5 6986A>G and ABCB1 3435C>T gene polymorphism. Patients were divided into groups based on the tacrolimus IPV tertiles and the median value of average C0/D during 6-12 months post-transplantation. RESULTS: The results showed a more pronounced decline in estimated glomerular filtration rate values within the high IPV tertile group (p = 0.018), as well as within the low C0/D group (p = 0.013) in a 3-year period after kidney transplantation. The carriers of CYP3A5*1/*3 genotype had lower C0/D compared to the CYP3A5*3/*3 carriers during the entire study period, while the results for ABCB1 were inconsistent when considering tacrolimus C0/D. Patients with high IPV/low C0/D had significantly reduced graft survival compared to the other tacrolimus IPV/C0/D combination groups (i.e., high IPV/high C0/D, low IPV/low C0/D, low IPV/high C0/D) with the hazard ratio of 3.14 in Cox analysis for reaching the composite endpoint. CONCLUSION: The findings of this study suggest that combined assessment of tacrolimus IPV and tacrolimus C0/D may categorize patients towards risk of graft deterioration in the long-term post-transplantation period.

Beta blocker rebound phenomenon is important, but we do not know its definition, incidence or optimal prevention strategies.

The aim of this review is to analyze whether there is a need for scientific information about the beta blocker (BB) rebound phenomenon; whether such information is available; and, if it is, how detailed is the BB rebound phenomenon explained in the guidelines and papers? A narrative review is used due to the lack of valid randomized clinical trials (RCTs) on the topic, which are needed for a meta-analysis. The BB rebound phenomenon can have dangerous consequences. The discontinuation of a BB leads to a fourfold increased risk of events related to coronary artery disease in hypertensive patients; it increases in-hospital mortality in heart failure patients; it can precipitate angina pectoris attack; and it increases the risk for death and rehospitalization in patients who survive acute myocardial infarction. Consequently, being considered in the guidelines, the BB rebound phenomenon is believed to be clinically relevant (by experts in the field). This is in sharp contrast with the lack of any additional relevant information about the BB rebound phenomenon in the various important guidelines. For example, we lack a consensus about the precise definition. Moreover, data about the incidence and optimal prevention strategies are lacking for the phenomenon (which is sometimes life-threatening). The BB rebound phenomenon is an additional reason why it is very important to test the prognosis of patients following the cessation of long-term medicaments in RCTs, particularly for BBs.

Adverse effects of mycophenolic acid in renal transplant recipients: gender differences.

Background Mycophenolic acid is widely used immunosuppressive drug, associated with adverse effects which increase patient morbidity and decrease medication adherence. Objective To evaluate the adverse effects in renal transplant recipients under mycophenolate treatment with respect to gender. Setting University Clinical Centre of Nis, Clinic of Nephrology, Serbia. Method This research included 96 renal transplant recipients, who received immunosuppressive regimen, based on tacrolimus or cyclosporin A, prednisone and mycophenolic acid. The high-performance liquid chromatography method combined with protein precipitation was used for the analysis of mycophelate concentration in human plasma. Drug concentration and dose-adjusted concentration were determined with respect to the patients' gender. An adverse effect scoring system developed by nephrologists within the University of Buffalo Nephrology/Transplant Program was used to monitor adverse effects of therapy. Main outcome measure Individual and scores of adverse effects in relation to the dosing regimen and gender. Results Results showed statistically lower dose and concentrations in men compared to the women in our investigation group. Also, female patients demonstrated higher mean scores (cumulative and subscores) within the same dosing regimens of mycophenolic acid. The gastrointestinal score was significantly higher in women who received a dose greater than 720 mg compared to men (0.20 ± 0.12 vs 0.12 ± 0.12). Women demonstrated higher individual adverse effects such as diarrhea and skin changes (41.7 vs 17.0; p = 0.038 and 62.5 vs 30.2; p = 0.037, respectively). Conclusions The results of our research showed that recipients' gender may play an important role in pharmacokinetic profile of mycophenolic acid, suggesting that women had higher concentration of mycophenolic acid and more serious side effects.

Metronidazole- and levofloxacin-induced psychotic disorders in chronic kidney patient.

We present a case which reports the occurrence of psychotic disorders after metronidazole and levofloxacin therapy in a chronic kidney patient while being treated for enterocolitis and urinary infection. A 48-year-old female was admitted to a hospital for the placement of a peritoneal dialysis catheter due to indicated peritoneal dialysis. During admission, symptoms of enterocolitis and urinary infection had occurred, so metronidazole and levofloxacin were introduced into therapy, respectively. After 4 days of metronidazole and 3 days of levofloxacin therapy, the patient became confused, disoriented, with signs of delirium. Since the diagnosis of psychoorganic disorder was made, the therapy with lorazepam and haloperidol was initiated, while metronidazole and levofloxacin were discontinued. Complete recovery 4 days after discontinuation indicates that the patient has experienced antibiotics-induced neurotoxicity. This is the first report of expressed neurotoxicity after the combination of metronidazole and levofloxacin in chronic kidney patients.

Potentially inappropriate prescribing among older patients and associated factors: comparison of two versions of STOPP/START criteria

Abstract The study aimed to estimate and compare the prevalence and type of potentially inappropriate medications (PIMs) and potential prescribing omissions (PPOs) between the STOPP/START original (v1) and updated version (v2) among older patients in various settings, as well as associated factors. The study included 440 patients attending a community pharmacy, 200 outpatients and 140 nursing home users. An increase in the prevalence of STOPP v2 (57.9%) compared to v1 (56.2%) was not statistically significant in the total sample and within each setting (p>0.05). A decrease in the prevalence of START v1 (55.8%) to v2 (41.2%) was statistically significant (p<0.001) in the total sample and within each setting (p<0.05). Drug indication (32.9%) and fall-risk medications (32.2%) were most commonly identified for STOPP v2, while cardiovascular system criteria (30.5%) were the most frequently detected for START v2. The number of medications was the strongest predictor for both STOPP v1 and v2, with odds ratio values of 1.35 and 1.34, respectively. Patients' characteristics associated with the occurrence of STOPP and START criteria were identified. According to both STOPP/START versions, the results indicate a substantial rate of potentially inappropriate prescribing among elderly patients. The prevalence of PIMs was slightly higher with the updated version, while the prevalence of PPOs was significantly lower