A review on renal toxicity profile of common abusive drugs

Analysis of drug of abuse compounds using passive sampling and ultrahigh-liquid chromatography coupled to mass spectrometry

The present study proposes the monitoring of compounds of drugs of abuse through the use of passive samplers in water systems. Initially, four positive ion compounds of interest were determined according to national surveys, and then composite sampling and passive sampling were implemented using continuous-flow passive samplers containing two types of sorbents, the Empore disk and Gerstel Twister. Two study sites were established at the beginning and at the end of the middle Bogotá River basin. After 4 days, the sorbents were removed so that they could be desorbed and analyzed using UHPLC-MS in the laboratory. For the composite samples, the results were below the first calibration curve point (FCCP) of the chromatographic method, and for passive sampling, peaks of benzoylecgonine (BE) (21427.3 pg mL-1), methamphetamine (MET) (67101.5 pg mL-1), MDMA (ecstasy) (225844.8 pg mL-1) and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) (15908.4 pg mL-1) were found. Therefore, passive sampling could be suggested as an alternative to composite sampling for the monitoring of compounds.

Caffeine Intake, Plasma Caffeine Level, and Kidney Function: A Mendelian Randomization Study

Caffeine is a psychoactive substance widely consumed worldwide, mainly via sources such as coffee and tea. The effects of caffeine on kidney function remain unclear. We leveraged the genetic variants in the CYP1A2 and AHR genes via the two-sample Mendelian randomization (MR) framework to estimate the association of genetically predicted plasma caffeine and caffeine intake on kidney traits. Genetic association summary statistics on plasma caffeine levels and caffeine intake were taken from genome-wide association study (GWAS) meta-analyses of 9876 and of >47,000 European ancestry individuals, respectively. Genetically predicted plasma caffeine levels were associated with a decrease in estimated glomerular filtration rate (eGFR) measured using either creatinine or cystatin C. In contrast, genetically predicted caffeine intake was associated with an increase in eGFR and a low risk of chronic kidney disease. The discrepancy is likely attributable to faster metabolizers of caffeine consuming more caffeine-containing beverages to achieve the same pharmacological effect. Further research is needed to distinguish whether the observed effects on kidney function are driven by the harmful effects of higher plasma caffeine levels or the protective effects of greater intake of caffeine-containing beverages, particularly given the widespread use of drinks containing caffeine and the increasing burden of kidney disease.

The effect of cocaine on patients undergoing total hip arthroplasty

BACKGROUND

Cocaine use has surged in the past decade, with 4.8 million Americans (1.7% of the population greater than 12) reporting use in 2021, leading to a healthcare burden of 1.3 billion dollars. Cocaine users experience prolonged hospital stays, higher costs, worse surgical outcomes, increased risk of medical conditions, and inflammation-related osteoarthritis. The study aims to identify factors influencing length of stay, costs, and perioperative complications in cocaine users undergoing total hip arthroplasty (THA) to reduce these risks.

METHODS

This study utilized the NIS database, providing comprehensive information on patient demographics, length of stay, hospital costs, and complications. Statistical analyses were conducted using SPSS software, including propensity matching and significance testing, to compare outcomes between cocaine users (CU) and non-cocaine users (NCU) undergoing total hip arthroplasty.

RESULTS

After propensity matching, cocaine users had a significantly longer LOS (4.8 days) in comparison to non-cocaine users (2.6 days) (p < 0.001). Similarly, the CU group had a larger of care (87984.9) than the NCU group (69149.2) (p < 0.001). Cocaine users had significantly higher rates of blood loss anemia (OR: 3.24, 95% CI: 2.21, 4.73), blood loss anemia (OR: 1.59, 95% CI: 1.12, 2.24), blood transfusion (OR: 2.23, 95% CI: 1.04, 4.78), periprosthetic dislocation (OR: 6.57, 95% CI: 1.47, 29.32), and periprosthetic infection (OR: 4.59, 95% CI: 1.54, 13.68) than patients in the non-cocaine user's group.

CONCLUSION

Cocaine users had a significantly longer length of stay, higher costs of care, and an increased number of post-operative complications compared to non-cocaine users. These data contribute to understanding the potential ramifications of cocaine users undergoing THA.

CYP1A2 Genetic Variation, Coffee Intake, and Kidney Dysfunction

IMPORTANCE

Caffeine is detoxified by cytochrome P450 1A2 (CYP1A2), and genetic variation in CYP1A2 impacts the rate of caffeine clearance. Factors that may modify the association between coffee intake and kidney disease remain unclear.

OBJECTIVE

To assess whether CYP1A2 genotype modifies the association between coffee intake and kidney dysfunction.

DESIGN, SETTING, AND PARTICIPANTS

The Hypertension and Ambulatory Recording Venetia Study (HARVEST) was a prospective cohort study of individuals with stage 1 hypertension in Italy; HARVEST began on April 1, 1990, and follow-up is ongoing. The current study used data from April 1, 1990, to June 30, 2006, with follow-up of approximately 10 years. Blood pressure and biochemical data were collected monthly during the first 3 months, then every 6 months thereafter. Data were analyzed from January 2019 to March 2019. Participants were screened and recruited from general practice clinics. The present study included 1180 untreated participants aged 18 to 45 years with stage 1 hypertension; those with nephropathy, diabetes, urinary tract infection, and cardiovascular disease were excluded.

EXPOSURES

Coffee intake and CYP1A2 genotype rs762551 were exposures analyzed over a median follow-up of 7.5 (IQR, 3.1-10.9) years.

MAIN OUTCOMES AND MEASURES

Albuminuria (defined as an albumin level of ≥30 mg/24 h) and hyperfiltration (defined as an estimated glomerular filtration rate of ≥150 mL/min/1.73 m2) were the primary outcomes as indicators of kidney dysfunction.

RESULTS

Among 1180 participants, genotyping, lifestyle questionnaires, and urine analysis data were obtained from 604 individuals (438 [72.5%] male) with a mean (SD) age of 33.3 (8.5) years and a mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 25.4 (3.4). A total of 158 participants (26.2%) consumed less than 1 cup of coffee per day, 379 (62.7%) consumed 1 to 3 cups per day, and 67 (11.1%) consumed more than 3 cups per day. Genotype frequencies for rs762551 (260 participants [43.1%] with genotype AA, 247 participants [40.8%] with genotype AC, and 97 participants [16.1%] with genotype CC) did not differ between coffee intake categories. The level of risk of developing albuminuria, hyperfiltration, and hypertension, assessed by Cox regression and survival analyses, was not associated with coffee intake in the entire group or among fast metabolizers. The risks of albuminuria (adjusted hazard ratio [aHR], 2.74; 95% CI, 1.63-4.62; P < .001), hyperfiltration (aHR, 2.11; 95% CI, 1.17-3.80; P = .01), and hypertension (aHR, 2.81; 95% CI, 1.51-5.23; P = .001) increased significantly among slow metabolizers who consumed more than 3 cups per day.

CONCLUSIONS AND RELEVANCE

In this study, the risks of albuminuria, hyperfiltration, and hypertension increased with heavy coffee intake only among those with the AC and CC genotypes of CYP1A2 at rs762551 associated with slow caffeine metabolism, suggesting that caffeine may play a role in the development of kidney disease in susceptible individuals.

Use of in vitro metabolomics in NRK cells to help predicting nephrotoxicity and differentiating the MoA of nephrotoxicants

We describe a strategy using an in vitro metabolomics assay with tubular rat NRK-52E cells to investigate the Modes of Action (MoAs) of nephrotoxic compounds. Chemicals were selected according to their MoAs based on literature information: acetaminophen, 4-aminophenol and S-(trichlorovinyl-)L-cysteine (TCVC), (covalent protein binding); gentamycin, vancomycin, polymycin B and CdCl₂ (lysosomal overload) and tenofovir and cidofovir (mitochondrial DNA-interaction). After treatment and harvesting of the cells, intracellular endogenous metabolites were quantified relative to vehicle control. Metabolite patterns were evaluated in a purely data-driven pattern generation process excluding published information. This strategy confirmed the assignment of the chemicals to the respective MoA except for TCVC and CdCl₂. Finally, TCVC was defined as unidentified and CdCl₂ was reclassified to the MoA "covalent protein binding". Hierarchical cluster analysis of 58 distinct metabolites from the patterns enabled a clear visual separation of chemicals in each MoA. The assay reproducibility was very good and metabolic responses were consistent. These results support the use of metabolome analysis in NRK-52E cells as a suitable tool for understanding and investigating the MoA of nephrotoxicants. This assay could enable the early identification of nephrotoxic compounds and finally reduce animal testing.

Blood lead concentration among oral/inhaled opium users: systematic review and meta-analysis

Lead is a poisonous heavy metal with various known side effects. The effect of opium on raising blood lead concentration (BLC) has been investigated with no general agreement. In Iran, the number of lead poisoning cases has raised among the opium-addicted population. This systematic review and meta-analysis aim to combine the results of previous studies with the Iranian population to investigate the effect of opium on BLC. In this systematic review, PubMed/Medline, Web of Sciences, Embase, and Scopus were searched for studies using the Iranian population to compare the BLC of opium-addicted cases and non-addicted controls till January 2020. A random-effects model was used to pool the results. I-square test was used to assess the heterogeneity of the studies. The effect sizes were standardized mean differences (proxied by Hedges' g) followed by a 95% confidence interval. Of 417 initial articles, 13 studies met the inclusion criteria to be considered in the meta-analysis. The sample size of eligible studies ranged from 40 to 131 (mean 81.83, SD 27.6). All studies were focused on adults with mean age ranged from 33.5 to 65.15 years old (overall mean 49.0, SD 7.66). There were 13 studies included with 18 Hedges' g effect sizes. Using a random effect model, the pooled effect size was g_w = 2.48 (95% CI: 1.58-3.39) and statistically significant in favor of opium-addicted participants. Moreover, heterogeneity was 96.6% (I2=96.6, Q(17) = 504.95, p < 0.001). For studies with large Hedges' g effect sizes (> 4) identified as outliers and removed from meta-analysis. The pooled Hedges' g effect size reduced to 1.39 (95% CI: 0.94-1.85), still highly significant in favor of higher levels of lead in the opium-addicted group. The funnel plot appeared symmetrical confirmed by Egger's test (t = 1.87, p = 0.088), indicating no publication bias present.

Repeated Administration of Clinical Doses of Tramadol and Tapentadol Causes Hepato- and Nephrotoxic Effects in Wistar Rats

Tramadol and tapentadol are fully synthetic and extensively used analgesic opioids, presenting enhanced therapeutic and safety profiles as compared with their peers. However, reports of adverse reactions, intoxications and fatalities have been increasing. Information regarding the molecular, biochemical, and histological alterations underlying their toxicological potential is missing, particularly for tapentadol, owing to its more recent market authorization. Considering the paramount importance of liver and kidney for the metabolism and excretion of both opioids, these organs are especially susceptible to toxicological damage. In the present study, we aimed to characterize the putative hepatic and renal deleterious effects of repeated exposure to therapeutic doses of tramadol and tapentadol, using an in vivo animal model. Male Wistar rats were randomly divided into six experimental groups, composed of six animals each, which received daily single intraperitoneal injections of 10, 25 or 50 mg/kg tramadol or tapentadol (a low, standard analgesic dose, an intermediate dose and the maximum recommended daily dose, respectively). An additional control group was injected with normal saline. Following 14 consecutive days of administration, serum, urine and liver and kidney tissue samples were processed for biochemical, metabolic and histological analysis. Repeated administration of therapeutic doses of both opioids led to: (i) increased lipid and protein oxidation in liver and kidney, as well as to decreased total liver antioxidant capacity; (ii) decreased serum albumin, urea, butyrylcholinesterase and complement C3 and C4 levels, denoting liver synthesis impairment; (iii) elevated serum activity of liver enzymes, such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyl transpeptidase, as well as lipid profile alterations, also reflecting hepatobiliary commitment; (iv) derangement of iron metabolism, as shown through increases in serum iron, ferritin, haptoglobin and heme oxygenase-1 levels. In turn, elevated serum cystatin C, decreased urine creatinine output and increased urine microalbumin levels were detected upon exposure to tapentadol only, while increased serum amylase and urine N-acetyl-β-D-glucosaminidase activities were observed for both opioids. Collectively, these results are compatible with kidney injury. Changes were also found in the expression levels of liver- and kidney-specific toxicity biomarker genes, upon exposure to tramadol and tapentadol, correlating well with alterations in lipid profile, iron metabolism and glomerular and tubular function. Histopathological analysis evidenced sinusoidal dilatation, microsteatosis, mononuclear cell infiltrates, glomerular and tubular disorganization, and increased Bowman's spaces. Although some findings are more pronounced upon tapentadol exposure, our study shows that, when compared with acute exposure, prolonged administration of both opioids smooths the differences between their toxicological effects, and that these occur at lower doses within the therapeutic range.

Herbal Nephropathy

This column is supplied by Amita Jain, MD, and Juan Jose Olivero, MD. Dr. Jain completed an internal medicine residency at Houston Methodist Hospital in Houston, Texas, and recently joined a primary care practice in Delaware. She earned a Bachelor of Medicine and Surgery (MBBS) degree, with a distinction in microbiology, from Terna Medical College at the Maharashtra University of Health Sciences in Navi Mumbai, India. Before coming to Houston, Dr. Jain completed residency training in internal medicine and allied subspecialties at the Dr. Babasaheb Ambedkar Memorial Hospital in Byculla, Mumbai. Dr. Olivero is a nephrologist at Houston Methodist Hospital and a member of the hospital's Nephrology Training Program. He obtained his medical degree from the University of San Carlos School of Medicine in Guatemala, Central America, and completed his residency and nephrology fellowship at Baylor College of Medicine in Houston, Texas.

Traditional Chinese Medicine-Guided Dietary Intervention for Male Youth Undergoing Drug Detoxification: A Randomized Controlled Trial

Objective

The aim of this study was to evaluate the effectiveness of traditional Chinese medicine- (TCM-) guided dietary interventions in improving yang-qi deficiency and yin-blood deficiency TCM syndromes according to the principles of TCM syndrome differentiation theory in male youths undergoing drug detoxification during the rehabilitation period who stayed in a compulsory isolation detoxification center.

Methods

Male youths undergoing drug detoxification who met the criteria to be included in the study were randomly divided into the intervention group (n = 62) and the control group (n = 61) according to a random number table in a 1 : 1 ratio. The intervention group received a TCM-guided diet, and the control group received routine food support. Over an intervention period of 3 months, we observed changes in the TCM syndrome element scores in the two groups before and after intervention.

Results

After 3 months, the qi deficiency, yin deficiency, blood deficiency, and yin-blood deficiency syndrome in the intervention group improved significantly (P values 0.009, 0.000, 0.005, and 0.001, respectively). In the control group, yang deficiency, qi deficiency, and yang-qi deficiency syndromes worsened significantly (P values 0.003, 0.032, and 0.009, respectively). The differences (post-pre) in yang deficiency, qi deficiency, yang-qi deficiency, yin deficiency, blood deficiency, and yin-blood deficiency syndromes between the two groups were statistically significant (P values 0.003, 0.003, 0.003, 0.001, 0.005, and 0.002, respectively).

Conclusion

A TCM-guided diet can delay the worsening of yang-qi deficiency syndrome symptoms and improve yin-blood deficiency syndrome and the prognosis of male youth undergoing drug detoxification during the rehabilitation period.

Effects of concurrent chloroquine and ethanol administration on the rat kidney morphology

Introduction

The use of antimalarial chloroquine in malaria-endemic regions of Africa is rampant and it is not uncommon to find individuals taken the drug concurrent with alcohol. Effects of anti-malarial drug chloroquine (Chq) and ethanol (Et) combination on kidney volume and function using rat model was investigated.

Methods

32 adult male rats were randomly distributed into four groups of 8 rats each. Group C serve as control and received vehicle only, while Q is Chq treated only, E is Et treated and QE is Et and Chq treated. Chq was administered intraperitoneally at 1mg/100g body weight weekly and 6% Et in drinking water provided ad libitum. Urine volume was collected before the treatment began and after the treatment. After eight weeks, all animals were euthanized; kidneys were harvested and fixed in 10% neutral formalin. The fixed left kidneys were scanned with computed tomography and the scan slices were used to estimate 3-dimensional kidney volume on ImageJ.

Results

Total kidney volume was none significantly increased in Q, E and QE treated compared to control groups (p = 0.5150). Also, microscopic analysis showed increased proximal tubule diameter (p = 0.1426) and epithelial hypertrophy (p = 0.2530) and significant urinary space shrinkage (p = 0.00001). The initial urine volume was not significantly different between the control and treated groups (p = 0.9864) however, following treatment urine volume was significantly reduced in QE rats group (p = 0.0029).

Conclusion

The results suggest chloroquine and ethanol combination as potential cause of kidney injury through structural damage and function derangement.

Puérperas dependientes de crack: dificultades y facilidades afrontadas en el cuidado al recién nacido

Introducción: los recién nacidos de dependientes de crack sufren los efectos de la dependencia ya en las primeras horas de vida y pueden presentar cuadro de irritabilidad, sudoración, hipertonía y dificultad en los ciclos de sueño y vigilia. Esta realidad requiere el auxilio profesional a la puérpera usuaria de crack para su instrumentalización al cuidado del recién nacido. Objetivo: conocer dificultades y facilidades de puérperas dependientes de crack en el cuidado al recién nacido. Método: se realizó investigación con enfoque cualitativo en una maternidad del sur de Brasil, por medio de entrevistas semiestructuradas con 18 puérperas. Resultados: desde el análisis de contenido, se identificaron como dificultades: abstinencia de la droga, no lactancia, falta de respaldo familiar, vigilancia de los profesionales del Consejo Tutelar (Similar al Bienestar Familiar en Colombia), falta de habilidad para la realización de cuidados directos al recién nacido, miedo a lastimarlo y falta de condiciones financieras. Como facilidades, se encontró que el recién nacido llore poco, sea tranquilo y quieto; respaldo de la familia, vecinos y amigos, y auxilio financiero del compañero y familiares. Conclusión: puérperas dependientes de crack necesitan de auxilio para que cumplan su rol de cuidadoras del recién nacido. Deben ser identificadas durante el embarazo y acompañadas de forma a que realicen el prenatal, orientadas acerca de los cuidados con el niño y recibidas en servicios de apoyo.

Maternal Hypercholesterolemia Associated with Nicotine Exposure in Adulthood May Induce Kidney Injury in Male Rats if Hypomagnesemia Occurs

BACKGROUND/AIMS

Maternal hypercholesterolemia is a risk factor to renal injury in rat pups at adulthood, especially if they feed a cholesterol-enriched diet after weaning. However, the renal function of male pups of dams with hypercholesterolemia (PH) that were fed a regular chow from weaning to adulthood needs investigation, particularly those exposed to an adverse risk such as nicotine.

METHODS

We evaluated the renal function of PH animals and we compared the data with those found in male pups of control dams (PC) at 3- and 6-month-old by inulin clearance. Moreover, we investigated the effect of nicotine treatment for 8 days in both PH and PC animals at 6 months old via metabolic function studies and by renal histological analysis.

RESULTS

Inulin clearance and other renal function parameters were similar in PH and PC animals at 3 and 6 months old. Nevertheless, the PH group showed significant differences with regard to histological analysis despite a similar number of glomeruli. The glomerular area of PH animals was significantly smaller than that measured in PC animals, and the fractional interstitial area was significantly larger in PH animals than that measured in PC animals at 3 months old. With regard to nicotine treatment, we observed a trend for a reduction in creatinine clearance in both PC and PH groups, but only PH animals showed hypomagnesemia and the highest fractional interstitial area.

CONCLUSIONS

The offspring exposed to a high cholesterol milieu during intrauterine and neonatal life may show a silent kidney injury at adulthood that may be aggravated by nicotine exposure if hypomagnesemia occurs.

Acute administration of tramadol and tapentadol at effective analgesic and maximum tolerated doses causes hepato- and nephrotoxic effects in Wistar rats

Tramadol and tapentadol are two atypical synthetic opioid analgesics, with monoamine reuptake inhibition properties. Mainly aimed at the treatment of moderate to severe pain, these drugs are extensively prescribed for multiple clinical applications. Along with the increase in their use, there has been an increment in their abuse, and consequently in the reported number of adverse reactions and intoxications. However, little is known about their mechanisms of toxicity. In this study, we have analyzed the in vivo toxicological effects in liver and kidney resulting from an acute exposure of a rodent animal model to both opioids. Male Wistar rats were intraperitoneally administered with 10, 25 and 50mg/kg tramadol and tapentadol, corresponding to a low, effective analgesic dose, an intermediate dose and the maximum recommended daily dose, respectively, for 24h. Toxicological effects were assessed in terms of oxidative stress, biochemical and metabolic parameters and histopathology, using serum and urine samples, liver and kidney homogenates and tissue specimens. The acute exposure to tapentadol caused a dose-dependent increase in protein oxidation in liver and kidney. Additionally, exposure to both opioids led to hepatic commitment, as shown by increased serum lipid levels, decreased urea concentration, increased alanine aminotransferase and decreased butyrylcholinesterase activities. It also led to renal impairment, as reflected by proteinuria and decreased glomerular filtration rate. Histopathological findings included sinusoidal dilatation, microsteatosis, vacuolization, cell infiltrates and cell degeneration, indicating metabolic changes, inflammation and cell damage. In conclusion, a single effective analgesic dose or the maximum recommended daily dose of both opioids leads to hepatotoxicity and nephrotoxicity, with tapentadol inducing comparatively more toxicity. Whether these effects reflect risks during the therapeutic use or human overdoses requires focused attention by the medical community.

Preparation and therapeutic evolution of Ficus benjamina solid lipid nanoparticles against alcohol abuse/antabuse induced hepatotoxicity and cardio-renal injury

Chronic alcoholism destroys the propensity for hepatic detoxification of toxic substances, which further promotes the rapid and intense accumulation of aldehydes in the liver.

Diallyl disulfide attenuates acetaminophen-induced renal injury in rats

This study investigated the protective effects of diallyl disulfide (DADS) against acetaminophen (AAP)-induced acute renal injury in male rats. We also investigated the effects of DADS on kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL), which are novel biomarkers of nephrotoxicity in renal tissues, in response to AAP treatment. The following four experimental groups were evaluated: (1) vehicle control, (2) AAP (1,000 mg/kg), (3) AAP&DADS, and (4) DADS (50 mg/kg/day). AAP treatment caused acute kidney injury evidenced by increased serum blood urea nitrogen (BUN) levels and histopathological alterations. Additionally, Western blot and immunohistochemistry analysis showed increased expression of KIM-1 and NGAL proteins in renal tissues of AAP-treated rats. In contrast, DADS pretreatment significantly attenuated the AAP-induced nephrotoxic effects, including serum BUN level and expression of KIM-1 and NGAL proteins. Histopathological studies confirmed the renoprotective effect of DADS. The results suggest that DADS prevents AAP-induced acute nephrotoxicity, and that KIM-1 and NGAL may be useful biomarkers for the detection and monitoring of acute kidney injury associated with AAP exposure.

Predominant D1 Receptors Involvement in the Over-expression of CART Peptides after Repeated Cocaine Administration

The aim of this study was to investigate the involvement of dopaminergic receptors (DR) in behavioral sensitization, as measured by locomotor activity, and the over-expression of cocaine- and amphetamine-regulated transcript (CART) peptides after repeated administration of cocaine in mice. Repeated administrations of cocaine induced behavioral sensitization and CART over-expression in mice. The levels of striatal CART mRNA were significantly increased on the 3^rd day. CART peptides were over-expressed on the 5^th day in the striata of behaviorally sensitized mice. A higher proportion of CART⁺ cells in the cocaine-treated mice were present in the nucleus accumbens (NAc) shell than in the dorsolateral (DL) part of caudate putamen (CP). The concomitant administration of both D₁R and D₂R antagonists, SCH 23390 (D₁R selective) and raclopride (D₂R selective), blocked cocaine induced-behavioral sensitization, CART over-expression, and cyclic adenosine 5'-monophosphate (cAMP)/protein kinase A (PKA)/phospho-cAMP response element-binding protein (pCREB) signal pathways. SCH 23390 more predominantly inhibited the locomotor activity, CART over-expression, pCREB and PKA activity than raclopride. Cocaine induced-behavioral sensitization was also attenuated in the both D₁R and D₂R knockout (KO) mice, respectively. CART over-expression and activated cAMP/PKA/pCREB signal pathways were inhibited in the D₁R-KO mice, but not in the D₂R-KO mice. It is suggested that behavioral sensitization, CART over-expression and activated cAMP/PKA/pCREB signal pathways induced by repeated administration of cocaine could be more predominantly mediated by D₁R.

Prediction of Pharmacokinetics and Penetration of Moxifloxacin in Human with Intra-Abdominal Infection Based on Extrapolated PBPK Model

The aim of this study is to develop a physiologically based pharmacokinetic (PBPK) model in intra-abdominal infected rats, and extrapolate it to human to predict moxifloxacin pharmacokinetics profiles in various tissues in intra-abdominal infected human. 12 male rats with intra-abdominal infections, induced by Escherichia coli, received a single dose of 40 mg/kg body weight of moxifloxacin. Blood plasma was collected at 5, 10, 20, 30, 60, 120, 240, 480, 1440 min after drug injection. A PBPK model was developed in rats and extrapolated to human using GastroPlus software. The predictions were assessed by comparing predictions and observations. In the plasma concentration versus time profile of moxifloxcinin rats, C_max was 11.151 µg/mL at 5 min after the intravenous injection and t_1/2 was 2.936 h. Plasma concentration and kinetics in human were predicted and compared with observed datas. Moxifloxacin penetrated and accumulated with high concentrations in redmarrow, lung, skin, heart, liver, kidney, spleen, muscle tissues in human with intra-abdominal infection. The predicted tissue to plasma concentration ratios in abdominal viscera were between 1.1 and 2.2. When rat plasma concentrations were known, extrapolation of a PBPK model was a method to predict drug pharmacokinetics and penetration in human. Moxifloxacin has a good penetration into liver, kidney, spleen, as well as other tissues in intra-abdominal infected human. Close monitoring are necessary when using moxifloxacin due to its high concentration distribution. This pathological model extrapolation may provide reference to the PK/PD study of antibacterial agents.

Cocaine and kidney injury: a kaleidoscope of pathology

Cocaine is abused worldwide as a recreational drug. It is a potent activator of the sympathetic nervous system leading to intense vasoconstriction, endothelial dysfunction, oxidative stress, platelet activation and decrease in prostaglandins E2 and prostacyclin. Cocaine can lead to widespread systemic adverse effects such as stroke, myocardial infarction, arterial dissection, vascular thrombosis and rhabdomyolysis. In human and rat kidneys, cocaine has been associated with glomerular, tubular, vascular and interstitial injury. It is not uncommon to diagnose cocaine-related acute kidney injury (AKI), malignant hypertension and chronic kidney disease. Cocaine abuse can lead to AKI by rhabdomyolysis, vasculitis, infarction, thrombotic microangiopathy and malignant hypertension. It is reported that 50–60% of people who use both cocaine and heroin are at increased risk of HIV, hepatitis and additional risk factors that can cause kidney diseases. While acute interstitial nephritis (AIN) is a known cause of AKI, an association of AIN with cocaine is unusual and seldom reported. We describe a patient with diabetes mellitus, hypertension and chronic hepatitis C, who presented with AKI. Urine toxicology was positive for cocaine and a kidney biopsy was consistent with AIN. Illicit drugs such as cocaine or contaminants may have caused AIN in this case and should be considered in the differential diagnosis of causes of AKI in a patient with substance abuse. We review the many ways that cocaine adversely impacts on kidney function.

Interplay between RAS and opioids: opening the Pandora of complexities

Angiotensin and endogenous opioids are important bioactive neuropeptides, which are widely distributed in the brain and peripheral regions to produce diverse biological and neurobiological activities. An endogenous opioid system includes proopiomelanocortin-derived enkephalin, dynorphin and endorphin that act on their specific receptors such as delta (δ), kappa (κ) and mu (μ) receptors. Research evidence demonstrates significant positive as well as negative interactions between renin angiotensin system (RAS) and endogenous opioids in the brain and periphery. The diverse actions of Ang II are possibly mediated indirectly through endogenous opioids, while opioids are also shown to activate RAS components suggesting the up-regulation of each system in concern with each other. On the contrary, there are reports suggesting a negative correlation between RAS and opioid system. Research evidence also supports the notion that Ang II acts as anti-opioid peptide to decrease the actions of opioids. Moreover, opioids-induced decline in angiotensin release and functioning has also been reported. Co-administration of ACE inhibitors with opioids exhibits significant interactions possibly due to decreased metabolism of opioids leading to potentiation of their actions. The present review describes the complexities of positive and negative interactions between RAS and opioids along with possible mechanisms responsible for these interactions.