Recruitment or activation of mast cells in the liver aggravates the accumulation of fibrosis in carbon tetrachloride-induced liver injury.

Liver diseases caused by viral infections, alcoholism, drugs, or chemical poisons are a significant health problem: Liver diseases are a leading contributor to mortality, with approximately 2 million deaths per year worldwide. Liver fibrosis, as a common liver disease characterized by excessive collagen deposition, is associated with high morbidity and mortality, and there is no effective treatment. Numerous studies have shown that the accumulation of mast cells (MCs) in the liver is closely associated with liver injury caused by a variety of factors. This study investigated the relationship between MCs and carbon tetrachloride (CCl4)-induced liver fibrosis in rats and the effects of the MC stabilizers sodium cromoglycate (SGC) and ketotifen (KET) on CCl4-induced liver fibrosis. The results showed that MCs were recruited or activated during CCl4-induced liver fibrosis. Coadministration of SCG or KET alleviated the liver fibrosis by decreasing SCF/c-kit expression, inhibiting the TGF-ß1/Smad2/3 pathway, depressing the HIF-1a/VEGF pathway, activating Nrf2/HO-1 pathway, and increasing the hepatic levels of GSH, GSH-Px, and GR, thereby reducing hepatic oxidative stress. Collectively, recruitment or activation of MCs is linked to liver fibrosis and the stabilization of MCs may provide a new approach to the prevention of liver fibrosis.

Mitochondrial uptake of aristolactam I plays a critical role in its toxicity.

Aristolochic acid I (AAI), a component of aristolochic acids, can be converted to the toxic metabolite Aristolactam I (ALI) in vivo which forms aristolactam-nitrenium with delocalized positive charges. It is widely accepted that delocalized lipophilic cations can accumulate in mitochondria due to the highly negatively charged microenvironment of the mitochondrial matrix, but the uptake of ALI by mitochondria is not known. In this study, the cell uptake and mitochondrial localization of ALI, and its subsequent impact on mitochondrial function were investigated. Results show that ALI can rapidly penetrate HK-2 cells without relying on organic anion transporters 1/3 (OAT1/3). The cellular distribution of ALI was found to align with the observed distribution of a mitochondria-selective dye in HK-2 cells. Furthermore, the cell uptake and mitochondrial uptake of ALI were both inhibited by carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone, which induces mitochondrial membrane depolarization. These results suggest that ALI is selectively taken up by mitochondria. Consequently, mitochondrial dysfunction was observed after treatment with ALI. It should be noted that inhibiting OAT1/3 could result in an increased exposure of ALI in vivo and cause more seriously nephrotoxicity. In conclusion, this research reports the mitochondrial uptake of ALI and provides new insight on potential strategies for protection against AAI-induced nephrotoxicity.

Identification and characterization of endogenous biomarkers for hepatic vectorial transport (OATP1B3-P-gp) function using metabolomics with serum pharmacology.

The organic anion-transporting polypeptide 1B3 and P-glycoprotein (P-gp) provide efficient directional transport (OATP1B3-P-gp) from the blood to the bile that serves as a key determinant of hepatic disposition of the drug. Unfortunately, there is still a lack of effective means to evaluate the disposal ability mediated by transporters. The present study was designed to identify a suitable endogenous biomarker for the assessment of OATP1B3-P-gp function in the liver. We established stably transfected HEK293T-OATP1B3 and HEK293T-P-gp cell lines. Results showed that azelaic acid (AzA) was an endogenous substrate for OATP1B3 and P-gp using serum pharmacology combined with metabolomics. There is a good correlation between the serum concentration of AzA and probe drugs of rOATP1B3 and rP-gp when rats were treated with their inhibitors. Importantly, after 5-fluorouracil-induced rat liver injury, the relative mRNA level and expression of rOATP1B3 and rP-gp were markedly down-regulated in the liver, and the serum concentration of AzA was significantly increased. These observations suggest that AzA is an endogenous substrate of both OATP1B3 and P-gp, and may serve as a potential endogenous biomarker for the assessment of the function of OATP1B3-P-gp for the prediction of changes in the pharmacokinetics of drugs transported by OATP1B3-P-gp in liver disease states.

Effects of Early Versus Delayed Feeding in Patients With Acute Pancreatitis: A Systematic Review and Meta-analysis.

BACKGROUND: The aim of this study was to summarize the optimal strategy for early feeding in patients with acute pancreatitis. METHODS: The search was undertaken in electronic databases, which compared early with delayed feeding in acute pancreatitis. The primary outcome was the length of hospital stay (LOHS). The second outcomes were intolerance of refeeding, mortality, and total cost of each patient. This meta-analysis followed the "Preferred Reporting Items for Systematic Reviews and Meta-analyses" guideline. Research is registered by PROSPERO, CRD42020192133. RESULTS: A total of 20 trials involving 2168 patients were included, randomly assigned to the early feeding group (N = 1033) and delayed feeding group (N = 1135). The LOHS was significantly lower in the early feeding group than the delayed feeding group (mean difference: -2.35, 95% CI: -2.89 to -1.80; P < 0.0001), no matter the mild or severe subgroup ( Pint = 0.69). The secondary outcome of feeding intolerance and mortality were no significant difference (risk ratio: 0.96, 0.40 to 2.16, P = 0.87 and 0.91, 0.57 to 1.46, P = 0.69; respectively). Moreover, the hospitalization cost was significantly less in the early feeding group, resulting in an average savings of 50%. In patients with severe pancreatitis, early feeding after 24 hours may be beneficial ( Pint = 0.001). CONCLUSION: Early oral feeding can significantly reduce the LOHS and hospitalization costs in patients with acute pancreatitis without increasing feeding intolerance or mortality. In patients with severe pancreatitis, early feeding after 24 hours may be beneficial.

Accumulation of Renal Fibrosis in Hyperuricemia Rats Is Attributed to the Recruitment of Mast Cells, Activation of the TGF-ß1/Smad2/3 Pathway, and Aggravation of Oxidative Stress.

Renal fibrosis is relentlessly progressive and irreversible, and a life-threatening risk. With the continuous intake of a high-purine diet, hyperuricemia has become a health risk factor in addition to hyperglycemia, hypertension, and hyperlipidemia. Hyperuricemia is also an independent risk factor for renal interstitial fibrosis. Numerous studies have reported that increased mast cells (MCs) are closely associated with kidney injury induced by different triggering factors. This study investigated the effect of MCs on renal injury in rats caused by hyperuricemia and the relationship between MCs and renal fibrosis. Our results reveal that hyperuricemia contributes to renal injury, with a significant increase in renal MCs, leading to renal fibrosis, mitochondrial structural disorders, and oxidative stress damage. The administration of the MCs membrane stabilizer, sodium cromoglycate (SCG), decreased the expression of SCF/c-kit, reduced the expression of α-SMA, MMP2, and inhibited the TGF-ß1/Smad2/3 pathway, thereby alleviating renal fibrosis. Additionally, SCG reduced renal oxidative stress and mitigated mitochondrial structural damage by inhibiting Ang II production and increasing renal GSH, GSH-Px, and GR levels. Collectively, the recruitment of MCs, activation of the TGF-ß1/Smad2/3 pathway, and Ang II production drive renal oxidative stress, ultimately promoting the progression of renal fibrosis in hyperuricemic rats.

Multidisciplinary Guidelines for the Rational Use of Topical Non-Steroidal Anti-Inflammatory Drugs for Musculoskeletal Pain (2022).

(1) Background: Topical non-steroidal anti-inflammatory drugs (NSAIDs) are one of the primary drugs for treating musculoskeletal pain. However, there are currently no evidence-based recommendations about drug selection, drug administration, drug interactions, and use in special populations or other pharmacology-related content of such medications. To this end, the Chinese Pharmaceutical Association Hospital Pharmacy Professional Committee developed multidisciplinary guidelines on using topical NSAIDs to treat musculoskeletal pain. (2) Methods: The guidelines development process followed the World Health Organization guideline development handbook, the GRADE methodology, and the statement of Reporting Items for Practice Guidelines in Healthcare. The guideline panel used the Delphi method to identify six clinical questions to be addressed in the guidelines. An independent systematic review team conducted a systematic search and integration of evidence. (3) Results: Based on the balance between the benefits and harms of an intervention, the quality of the evidence, patient preferences and values, and resource utilization, the guideline panel developed 11 recommendations and nine expert consensuses on using topical NSAIDs to treat acute and chronic musculoskeletal pain. (4) Conclusions: Based on the effectiveness and overall safety of topical NSAIDs, we recommend patients with musculoskeletal pain use topical NSAIDs and suggest high-risk patients use topical NSAIDs, such as those with other diseases or receiving other concurrent treatments. The evidenced-based guidelines on topical NSAIDs for musculoskeletal pain incorporated a pharmacist perspective. The guidelines have the potential to facilitate the rational use of topical NSAIDs. The guideline panel will monitor the relevant evidence and update the recommendations accordingly.

Uric acid accumulation in the kidney triggers mast cell degranulation and aggravates renal oxidative stress.

The accumulation of uric acid (UA) in the body can lead to the occurrence of hyperuricemia or uric acid nephropathy. Mast cells (MCs) increase oxidative stress and release renin to promote the production of Ang II. The aim of this study was to investigate the effect of UA on MCs in rat kidneys and the association between MCs and renal injury. Our results show that UA accumulation in the kidney stimulated the degranulation of MCs and the release of renin to promote Ang II production, resulting in renal oxidative stress, mitochondrial structural damage, and microvascular system damage. The expression of urate-related transporters was regulated by the UA level and serum urinary toxins levels were substantially elevated in hyperuricemia. Administration of the MCs membrane stabilizer sodium cromoglycate (SCG) or the angiotensin receptor antagonist Valsartan decreased the production of renin and Ang II and relieved renal oxidative stress, mitigated mitochondrial structural damage and microvascular system damage, and promoted the excretion of UA and urinary toxins by increasing the expression of urate-related transporters. These results demonstrate that the accumulation of UA in the kidney can trigger the degranulation of MCs and promote the development of renal oxidative stress. Administration of SCG and Valsartan ameliorated UA-induced renal injury by inhibiting MCs degranulation and reducing renal oxidative stress by inhibiting renin and Ang II production and accelerating renal clearance of UA and uremic toxins.

7, 8-Dihydroxy-4-methyl coumarin alleviates cholestasis via activation of the Farnesoid X receptor in vitro and in vivo.

Cholestasis is primarily caused by bile acid homeostasis dysregulation, resulting in retention, aggregation, and accumulation of the toxic cholate in the hepatocytes. Existing therapies for cholestasis are limited, demanding the urgent development of novel drugs. As a result, targeting FXR specifically promises a unique treatment strategy for cholestasis. The current study aims to evaluate the influence of 7, 8-dihydroxy-4-methyl coumarin (DMC) against alpha-naphthyl isothiocyanate (ANIT)-induced liver injury in mice. The "Computer-Aided Drug Design" (CADD) and molecular docking study anticipated that DMC would proficiently bind and activate the FXR. Accordingly, the hepatoprotective activity of DMC against ANIT-induced hepatotoxicity and cholestasis was investigated in ANIT-treated HepaRG cells and the ANIT-induced cholestatic mouse model. Outcomes indicated the protective effects of DMC against ANIT toxicity in HepaRG cells after 24 h of intervention and animals after seven days of treatment. DMC partially blocks ANIT-induced increases in serum markers of hepatocellular injury, liver and gall bladder enlargement, and hepatic necrosis. Western blotting revealed that DMC alleviates ANIT-induced hepatotoxicity and cholestasis via activating the FXR receptor and regulating CYP7A1, the enzyme responsible for bile acid synthesis. DMC exhibited protective activity against cholestasis through activating FXR, suggesting it might be a promising strategy for preventing and treating cholestatic liver disease.

Enalapril increases the urinary excretion of metformin in rats by inducing multidrug and toxin excretion protein 1 in the kidney.

Two-thirds of patients with type 2 diabetes mellitus have hypertension, and thus the combination of two or more drugs to treat these diseases is common. It has been shown that the combination of metformin and enalapril has beneficial effects, but few studies have evaluated the interactions between these two drugs. This study investigated the effects of enalapril on the pharmacokinetics and urinary excretion of metformin in rats, with a focus on transporter-mediated drug interactions. Rats were dosed orally with metformin alone (100 mg/kg) or in combination with enalapril (4 mg/kg). The concentration of metformin was measured by high performance liquid chromatography and the level of organic cation transporters (rOCTs) and multidrug and toxin excretion protein 1 (rMATE1), which mediate the uptake and efflux of metformin, respectively, were evaluated by immunoblotting. After single and 7-day dosing, the plasma concentration of metformin in the co-administration group was significantly lower than that in the metformin-only group, and the CL/F and urinary excretion were increased in the co-administration group. Enalapril did not affect the Kp of metformin but reduced renal slice-uptake of metformin. The expression of rMATE1 was increased, whereas rOCT2 expression was decreased in rat kidney. Importantly, long-term co-administration of metformin and enalapril markedly decreased the level of lactic acid and uric acid in the blood. Enalapril increases the urinary excretion of metformin through the up-regulation of rMATE1. This reveals a new mechanism of drug interactions and provides a basis for drug dosage adjustment when these drugs are co-administered.

The influence of pharmaceutical care in patients with advanced non-small-cell lung cancer receiving combination cytotoxic chemotherapy and PD-1/PD-L1 inhibitors.

Background: Immune checkpoint inhibitors combined chemotherapy (ICIC) are widely used for various types of lung cancer in the past decade. However, ICIC related adverse events (AEs) are more serious than immune-related adverse events (irAE) or cytotoxic chemotherapy alone. Objective: This prospective interventional study aimed to evaluate the impact of the pharmaceutical care program in reducing adverse events and analyze pharmacy interventions in patients with NSCLC who receive ICIC therapies. Method: NSCLC patients were enrolled in this study, the pharmaceutical care program was introduced after patients received the second cycle ICIC therapies, and were followed by the pharmacist for 6 months after hospital discharge. The percentages of adverse events between patients in and after the first two cycles were analyzed and compared. Results: After the first two treatment cycles, the clinical pharmacist proposed 67 interventions in 30 patients. The most frequent types of intervention were drug discontinuation (40.3%, 27/67) followed by drug modification (14.9%, 10/67). There were significant decreases in AEs after the second cycle with respect to nausea (≥grade-2, 14% vs. 28.3%, p = 0.039), constipation (≥grade-2, 8.8% vs. 21.7%, p = 0.039), diarrhea (≥grade-2, 6% vs. 16.7%, p = 0.031), and myelosuppression (≥grade-2, 15.8% vs. 30.0%, p = 0.022). Conclusion: Provision of pharmaceutical care for NSCLC patients receiving ICIC therapies can optimize drug therapy and reduce adverse events.

Construction and Evaluation of a Novel Organic Anion Transporter 1/3 CRISPR/Cas9 Double-Knockout Rat Model.

BACKGROUND: Organic anion transporter 1 (OAT1) and OAT3 have an overlapping spectrum of substrates such that one can exert a compensatory effect when the other is dysfunctional. As a result, the knockout of either OAT1 or OAT3 is not reflected in a change in the excretion of organic anionic substrates. To date, only the mOAT1 and mOAT3 individual knockout mouse models have been available. METHODS: In this study, we successfully generated a Slc22a6/Slc22a8 double-knockout (KO) rat model using CRISPR/Cas9 technology and evaluated its biological properties. RESULTS: The double-knockout rat model did not expression mRNA for rOAT1 or rOAT3 in the kidneys. Consistently, the renal excretion of p-aminohippuric acid (PAH), the classical substrate of OAT1/OAT3, was substantially decreased in the Slc22a6/Slc22a8 double-knockout rats. The relative mRNA level of Slco4c1 was up-regulated in KO rats. No renal pathological phenotype was evident. The renal elimination of the organic anionic drug furosemide was nearly abolished in the Slc22a6/Slc22a8 knockout rats, but elimination of the organic cationic drug metformin was hardly affected. CONCLUSIONS: These results demonstrate that this rat model is a useful tool for investigating the functions of OAT1/OAT3 in metabolic diseases, drug metabolism and pharmacokinetics, and OATs-mediated drug interactions.

The role of the farnesoid X receptor in quadruple anti-tuberculosis drug-induced liver injury.

Anti-tuberculosis drugs-induced liver injury may be associated with the hepatic farnesoid X receptor (FXR). However, the relationship between isoniazid, rifampicin, pyrazinamide and ethambutol (HRZE) coadministration-induced liver injury and FXR has not been clarified. The purpose of this study was to clarify the role of FXR in HRZE-induced liver injury. To measure indices of liver injury, blood samples were collected from clinical tuberculosis patients who had taken HRZE for approximately two months; in these patients serum total bile acids were increased, while other hepatic biochemical indexes showed no significant changes. When Wistar rats were orally administered isoniazid (30 or 60 mg/kg) + rifampicin (45 or 90 mg/kg) + pyrazinamide (150 or 300 mg/kg) + ethambutol (75 or 150 mg/kg) in combination for 15 days, the expression and function of FXR was up-regulated, and hepatic bile acids were decreased. However, following 30 days of HRZE treatment the expression and function of FXR was down-regulated and bile acids accumulated in the liver, suggestive of hepatotoxicity. Treatment of HepaRG cells with HRZE lead to time- and dose- dependent cytotoxicity, with the expression of FXR up-regulated in early stage, but down-regulated with prolonged HRZE treatment, consistent with the results of animal experiments. In summary, HRZE may upregulate FXR with short-term administration, but more prolonged treatment appears to suppress FXR function, resulting in hepatic bile acid accumulation.

Clinical Aspects of Drug-Drug Interaction and Drug Nephrotoxicity at Renal Organic Cation Transporters 2 (OCT2) and Multidrug and Toxin Exclusion 1, and 2-K (MATE1/MATE2-K).

The organic cation transporter 2 (OCT2) belongs to the SLC22 family, while the multidrug and toxin extrusion 1 and 2-K (MATE1/MATE2-K) belong to the SLC47 family, are localized to the basolateral and apical membrane of human renal proximal tubular epithelial cells, respectively. They are polyspecific transporters that enable the transit of structurally diversified drugs with overlapping selectivity across plasma membranes. OCT2 and MATE1/2-K are critically involved in renal secretion, pharmacokinetics (PK), and toxicity of cationic drugs. Drug-drug interactions (DDIs) at OCT2 and/or MATE1/2-K have been shown to result in clinical impacts on PK, therapeutic efficacy and are probably involved in the renal accumulation of drugs. Sites of OCT2 and MATE1/2-K expression and function play an essential role in the pharmacokinetics and toxicity of drugs, such as cisplatin. Thus, knowing the sites (basolateral vs. apical) of the interaction of two drugs at transporters is essential to understanding whether this interaction helps prevent or enhance drug-induced nephrotoxicity. In this work, an overview of OCT2 and MATE1/2-K is presented. Primary structure, membrane location, functional properties, and clinical impact of OCT2 and MATE1/2-K are presented. In addition, clinical aspects of DDIs in OCT2 and MATE1/2-K and their involvement in drug nephrotoxicity are compiled.

Application of physiologically based pharmacokinetic modelling for the prediction of drug-drug interactions involving anlotinib as a perpetrator of cytochrome P450 enzymes.

Anlotinib is a small molecule of novel tyrosine kinase inhibitor initially approved to treat non-small cell lung cancer in China. Drug-drug interaction (DDI) is an extrinsic factor important for the appropriate use of anlotinib in clinical practice. In vitro experiments demonstrated that anlotinib is a substrate of cytochrome P450 (CYP) enzymes and moderate inhibitor of several common ones; however, no clinical DDI studies have been performed to investigate inhibitory effects of anlotinib on these CYP enzymes. Thus, its drug label recommends avoiding co-administration with substrates of these enzymes, which have narrow therapeutic windows. In this study, we performed a CYP450 inhibition study, followed by gathering in vitro and clinical pharmacokinetic data to build the first physiologically based pharmacokinetic (PBPK) model of anlotinib. The verified model was subsequently used to predict the DDI mediated by anlotinib. As a result, the marginal plasma exposure changes of typical CYP3A and CYP2C9 substrates were less than the bioequivalence threshold, indicating that anlotinib has a very low potential of causing clinically meaningful DDI through the inhibition of several major CYP enzymes. According to the FDA's latest guideline on DDI, the established model with the simulation results may support the revision of anlotinib labelling without further clinical studies, lifting unnecessary restrictions on anlotinib regimens.

Adefovir accumulation in the renal interstitium triggers mast cell degranulation and promotes renal interstitial fibrosis.

Organic anion transporters 1 (OAT1) and OAT3 are responsible for transporting adefovir (ADV) into renal tubular epithelial cells. Our previous research found that ADV accumulated in the renal interstitium and caused renal interstitial fibrosis when Oat1/3 were inhibited by OATs inhibitor probenecid for long-term. Mast cells (MCs) in the interstitial space are considered to be key drivers of renal fibrosis. The current work investigated the effect of ADV on MCs in vitro and during the development of interstitial fibrosis in rats. Results indicate that ADV triggers chymase release from cultured RBL-2H3 mast cells in a time-and concentration-dependent manner. Angiotensin II (Ang II) in renal interstitium is generated mainly by chymase, renin and other products released from MCs, and has a direct effect on fibrosis through the angiotensin receptor. The concentrations of Ang II and fibrosis was significantly increased after administration of ADV alone or with probenecid for 4 weeks. The MCs membrane stabilizer sodium cromoglycate (SCG) and the angiotensin receptor antagonist Valsartan (VAL) could ameliorate ADV-induced nephrotoxicity. Additionally, SCG or VAL could reduce the accumulation of ADV in the renal interstitium by upregulating the expression of Oat1/3 and multidrug resistance-associated protein 4. Therefore, ADV accumulation in the renal interstitium could promote the degranulation of interstitial MCs and drive the development of renal fibrosis. SCG or VAL could ameliorate ADV-associated fibrosis by decreasing degranulation of MCs and accelerating renal clearance of ADV.

Tamsulosin alters the pharmacokinetics of metformin via inhibition of renal multidrug and toxin extrusion protein 1 and organic cation transporter 2 in rats.

Among the endocrine and metabolic disorders, type-2 diabetes mellitus (T2DM) and benign prostatic hyperplasia (BPH) are common progressive diseases related to aging. Metformin and tamsulosin as the first-choice drug for patients with T2DM and BPH, respectively, are often co-administered to male patients with T2DM and BPH. However, whether concomitantly administering metformin and tamsulosin leads to drug-drug interactions (DDIs) remains unclear. This study aimed to evaluate the effect of tamsulosin on the pharmacokinetics of metformin and explore the relevant underlying mechanism. The plasma, urine, and tissue concentrations of metformin were analyzed using HPLC, and metformin cell uptake was analyzed using LC-MS/MS. In addition, western blotting was used to investigate the expression of Oct1, Oct2, and Mate1. As demonstrated by comparison with metformin alone, tamsulosin significantly increased the area under concentration-time curves (AUC0-t), the maximum plasma concentration (Cmax) and the decreased 24 h cumulative urinary excretion of metformin after single or multiple-dose administration in rats, as well as increased the kidney tissue concentration of metformin after multiple-dose. In addition, tamsulosin treatment significantly inhibited the expression of Mate1 and Oct2 in rat kidneys, but Oct1 and Mate1 did not show a significant difference in the liver. Consistently, tamsulosin inhibited OCT2 and MATE1 expressions and decreased metformin uptake in HEK293 cells. Notably, serum LCA level in the co-administration group was increased by 34% and 39% after multiple-dose (7 and 14 consecutive days, respectively) administration compared to the metformin alone group. Altogether, our data suggest that tamsulosin could increase systemic exposure and reduce excretion of metformin via inhibiting Oct2 and Mate1-mediated transport cooperatively.

The utility of endogenous glycochenodeoxycholate-3-sulfate and 4ß-hydroxycholesterol to evaluate the hepatic disposition of atorvastatin in rats.

The liver is an important organ for drugs disposition, and thus how to accurately evaluate hepatic clearance is essential for proper drug dosing. However, there are many limitations in drug dosage adjustment based on liver function and pharmacogenomic testing. In this study, we evaluated the ability of endogenous glycochenodeoxycholate-3-sulfate (GCDCA-S) and 4ß-hydroxycholesterol (4ß-HC) plasma levels to evaluate organic anion-transporting polypeptide (Oatps)-mediated hepatic uptake and Cyp3a-meidated metabolism of atorvastatin (ATV) in rats. The concentration of ATV and its metabolites, 2-OH ATV and 4-OH ATV, was markedly increased after a single injection of rifampicin (RIF), an inhibitor of Oatps. Concurrently, plasma GCDCA-S levels were also elevated. After a single injection of the Cyp3a inhibitor ketoconazole (KTZ), plasma ATV concentrations were significantly increased and 2-OH ATV concentrations were decreased, consistent with the metabolism of ATV by Cyp3a. However, plasma 4ß-HC was not affected by KTZ treatment despite it being a Cyp3a metabolite of cholesterol. After repeated oral administration of RIF, plasma concentrations of ATV, 2-OH ATV and 4-OH ATV were markedly increased and the hepatic uptake ratio of ATV and GCDCA-S was decreased. KTZ did not affect plasma concentrations of ATV, 2-OH ATV and 4-OH ATV, but significantly decreased the metabolic ratio of total and 4-OH ATV. However, the plasma level and hepatic metabolism of 4ß-HC were not changed by KTZ. The inhibition of hepatic uptake of GCDCA-S by RIF was fully reversed after a 7-d washout of RIF. Plasma concentration and hepatic uptake ratio of GCDCA-S were correlated with the plasma level and hepatic uptake of ATV in rats with ANIT-induced liver injury, respectively. These results demonstrate that plasma GCDCA-S is a sensitive probe for the assessment of Oatps-mediated hepatic uptake of ATV. However, Cyp3a-mediated metabolism of ATV was not predicted by plasma 4ß-HC levels in rats.

Investigating Intestinal Transporter Involvement in Rivaroxaban Disposition through Examination of Changes in Absorption.

PURPOSE: The involvement of the intestinally expressed xenobiotic transporters P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP) have been implicated in rivaroxaban disposition based on in vitro studies, similar to what had previously been proposed for apixaban. We recently showed that these efflux transporters were not clinically relevant for apixaban disposition and examine here their relevance for this second Factor Xa inhibitor. METHODS: Using recently published methodologies to discern metabolic- from transporter- mediated drug interactions, a critical evaluation was undertaken of 9 rivaroxaban studies reporting 12 DDIs, one study of food effects and one study of hepatic function. RESULTS: Rationale examination of these clinical studies using basic pharmacokinetic theory finds little support for the clinical significance of intestinal efflux transporters in rivaroxaban disposition. Drug-drug interactions are most likely adequately predicted based on the level of CYP 3A metabolism. CONCLUSION: These analyses indicate that inhibition of efflux transporters appears to have negligible, clinically insignificant effects on the rivaroxaban absorption process, which is consistent with the concern that predictions based on in vitro measures may not translate to a clinically relevant interaction in vivo. We emphasize the need to evaluate gastric emptying, dissolution and other processes related to absorption when using MAT changes to indicate efflux transporter inhibition.

Effects of dibutyl phthalate on lipid metabolism in liver and hepatocytes based on PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway.

Phateacid esters (PAEs), such as dibutyl phthalate (DBP), have been widely used and human exposure results into serious toxic effects; such as the development of fatty liver disease. In the present study, SD rat models for in vivo study (normal and fatty liver model group) and hepatocytes for in vitro study (normal and abnormal lipid metabolism model group) were established to determine the effects of DBP on liver function and discover the possible mechanisms. Meanwhile, the peroxisome proliferator activated receptor (PPARα) blocker, GW6471, with the Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activator, AICAR, were applied in vitro study to clarify the role of PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway in the process. Results suggested that DBP could activate PPARα signaling pathway and affected the protein expression of SREBP, FAS and GPAT to cause hyperlipidemia and abnormal liver function. DBP also could inhibit the phosphorylation and activation of AMPK to inhibit the decomposition and metabolism of lipids. Interestingly, the effects of DBP could be alleviated by GW6471 and AICAR. Our experimental results provide reliable evidence that DBP exposure could further induce liver lipid metabolism disorder and other hepatic toxicity through PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway.

Evidence-based Guideline for Therapeutic Drug Monitoring of Vancomycin: 2020 Update by the Division of Therapeutic Drug Monitoring, Chinese Pharmacological Society.

BACKGROUND: Clinical practice guidelines or recommendations often require timely and regular updating as new evidence emerges, because this can alter the risk-benefit trade-off. The scientific process of developing and updating guidelines accompanied by adequate implementation can improve outcomes. To promote better management of patients receiving vancomycin therapy, we updated the guideline for the therapeutic drug monitoring (TDM) of vancomycin published in 2015. METHODS: Our updated recommendations complied with standards for developing trustworthy guidelines, including timeliness and rigor of the updating process, as well as the use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We also followed the methodology handbook published by the National Institute for Health and Clinical Excellence and the Spanish National Health System. RESULTS: We partially updated the 2015 guideline. Apart from adults, the updated guideline also focuses on pediatric patients and neonates requiring intravenous vancomycin therapy. The guideline recommendations involve a broadened range of patients requiring TDM, modified index of TDM (both 24-hour area under the curve and trough concentration), addition regarding the necessity and timing of repeated TDM, and initial dose for specific subpopulations. Overall, 1 recommendation was deleted and 3 recommendations were modified. Eleven new recommendations were added, and no recommendation was made for 2 clinical questions. CONCLUSIONS: We updated an evidence-based guideline regarding the TDM of vancomycin using a rigorous and multidisciplinary approach. The updated guideline provides more comprehensive recommendations to inform rational and optimized vancomycin use and is thus of greater applicability.