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Although carboplatin (CBDCA) is classified as a moderately emetogenic agent, the majority of guidelines recommend the use of a neurokinin-1 receptor antagonist in addition to a 5-hydroxytryptamine type 3 receptor antagonist with dexamethasone (DEX) for CBDCA-containing chemotherapy because of its higher emetogenic risk. However, the additional efficacy of aprepitant (APR) in CBDCA-containing treatment remains controversial, and data on multiple-day treatments are limited. Etoposide (ETP) was administered on days 1-3 in the CBDCA + ETP regimen, and it is important to evaluate suitable antiemetic therapy for the regimen. Therefore, we evaluated the efficacy of additional APR in CBDCA + ETP. Patients were divided into two groups and retrospectively evaluated. One was the control group, which was prophylactically administered palonosetron (PALO) and DEX, and the other was the APR group, which received APR orally with PALO and DEX. The primary endpoint was complete response (CR) between the groups. The overall CR rates were 75.0 and 76.4% in the control and APR groups, respectively, with no significant difference (p = 1.00). In the acute phase, it was 88.9 and 97.2%, respectively, and 86.1 and 79.2% in the delayed phase, respectively, without significant differences (p = 0.10 and 0.38, respectively). The incidence and severity of nausea, vomiting, and anorexia were not significantly different between the two groups in the acute and delayed phases. Our findings suggest that combining APR with PALO and DEX does not improve the CR rate in CBDCA + ETP therapy.

Platelets have been reported to exert diverse actions besides hemostasis and thrombus formation in the body. However, whether platelets affect transporter activity remains to be determined. In this study, we examined the effects of platelets on the activity of amino acid transporter system A, which is known to be changed by various factors, and we clarified the mechanism by which platelets affect system A activity. Among system A subtypes, we found that sodium-coupled neutral amino acid transporter (SNAT) 4 played a central role in the transport activity of system A in HuH-7 human hepatoma cells. Interestingly, platelets showed a biphasic effect on system A activity: activated platelet supernatants (APS) including the granule contents released from platelets downregulated system A activity at lower concentrations and the downregulation was suppressed at higher concentrations. The downregulation was due to a decrease in the affinity of SNAT4 for its substrate and not a decrease in the SNAT4 abundance on the plasma membrane. In addition, APS did not decrease the expression level of SNAT4 mRNA. On the other hand, platelets did not affect system A activity when the platelet suspension was added to HuH-7 cells. These results indicate that platelets indirectly affect the transport activity of system A by releasing bioactive substances but do not directly affect it by binding to HuH-7 cells.

The Child-Pugh score is widely used to assess liver function and estimate drug clearance in patients with liver cirrhosis. Recently, the albumin-bilirubin (ALBI) score, which objectively assesses liver function based only on albumin and total bilirubin levels, was developed as a new method. The purpose of this study was to analyze the relationship between the liver function assessment method and the plasma concentration of voriconazole (VRCZ), an antifungal drug for patients with liver cirrhosis. This single-center retrospective study enrolled 159 patients who received VRCZ between 2012 and 2020. In patients administered VRCZ orally, the median concentration to dose (C : D) ratio increased with the progression of Child-Pugh and ALBI grades. Positive correlations between the ALBI score and VRCZ C : D ratio were observed in patients with cirrhosis (r = 0.52 (95% confidence interval, 0.069-0.79); p < 0.05). In addition, a highly negative correlation was observed between the ALBI score and VRCZ daily maintenance dose (r=-0.79 (95% confidence interval, -0.92 to -0.50); p < 0.0001). In contrast, for patients administered VRCZ intravenously, no increase in C : D ratio was observed for both Child-Pugh and ALBI scores compared to the non-liver cirrhosis group. This may be because the injection is often used in severely ill patients, and factors other than impaired liver function may affect the plasma concentrations of VRCZ. In conclusion, the ALBI score was shown to be useful in predicting VRCZ clearance as well as the Child-Pugh score, and the initial dose of VRCZ might be determined according to the ALBI score.

Vancomycin (VCM)-induced nephrotoxicity (VIN) is a major side effect in paediatric patients. However, most studies are limited to patients aged 0-18 years. We evaluated the risk factors of VIN in patients aged 0-1 year using Japanese electronic medical record database. We used RWD database which was contained electronic medical records and claims data of approximately 20 million people from 160 medical institutions. We targeted hospitalized patients who were administered VCM between June 2000 and December 2020. VIN was defined by two criteria: Criterion 1 was an increase in serum creatinine (Scr) ≥ 0.5 mg/dL or 50% during VCM treatment period compared to the Scr baseline; and criterion 2 was an increase in Scr ≥50% within seven days or Scr ≥0.3 mg/dL within two days during VCM treatment. The risk factors of VIN were evaluated using multivariate logistic regression analysis. We analysed 446 patients; patients with VIN in Criteria 1 and 2 were 33 and 58, respectively. In Criterion 1, multivariate logistic regression analysis identified four independent factors with p-value <0.05 (VCM concentration ≥20 mg/L, amphotericin B (AMPH-B), piperacillin-tazobactam (TAZ/PIPC), and vasopressor drugs). In Criterion 2, multivariate logistic regression analysis identified concomitant use of vasopressor drugs with p-value <0.05. Therefore, concomitant use of vasopressor drugs was suggested to affect the risk of VIN in patients aged 0-1 year. The findings may help in developing estimation models to assess the risk of VIN in paediatric patients.

The modified Cockcroft-Gault (CG) equation, previously developed for an aged-oriented cohort, was validated in a newly obtained dataset. Estimates of creatinine clearance (CCr) using this equation were found to be more accurate than those determined using the conventional CG equation, particularly for patients exceeding 65 years of age. We identified a subset of patients in this cohort whose estimates were inadequate. Using statistical analysis, we found that the deviation from estimates was attributed to a decreased albumin level. In addition, we determined a reduced albumin cutoff value for the modified CG equation to obtain a good estimate. Univariate linear regression analysis was applied to measure the CCr in this cohort and identify parameters related to body composition, and we found that extracellular water (ECW)/total body water (TBW) and body fat (%) were relevant. Using measured values of ECW/TBW and body fat (%), a multivariate linear regression (MLR) estimating equation was developed based on the modified CG equation. This equation was applied to a cohort over 65 years of age, and it was found that a good estimate was obtained for older patients with low albumin levels. Thus, we propose a flow diagram that illustrates conditions for selecting an appropriate estimating equation from among the CG, modified CG, and MLR equations.

It is important to select appropriate antibiotics for infection control. Linezolid and tedizolid are newly developed and synthesized oxazolidinone antibacterial agents. It has been pointed out that there is a relationship between a high plasma concentration of the target drug and incidence of adverse effects, although it has been reported that neither linezolid nor tedizolid requires dose adjustment according to renal function. Due to the high incidence of adverse effects, both are often switched. Precise plasma concentration control by therapeutic drug monitoring (TDM) is desirable for reducing the adverse effects of both drugs and obtaining a better therapeutic effect. In this study, we aimed to establish a method for simultaneous quantification of linezolid and tedizolid in human plasma using LC coupled with tandem mass spectrometry. Sample preparation was performed by a simple operation with acetonitrile. Linezolid and tedizolid were separated by an octadecylsilyl column using a gradient elution of acetonitrile in aqueous 0.1% formic acid solution and were detected in the positive ion electrospray mode with multiple reaction monitoring. Quantification of linezolid and tedizolid ranged from 0.5 to 50 and 0.5 to 20 µg/mL, respectively. The intra-day and inter-day precision and accuracy of data were assessed and found to be acceptable. The developed method was successfully applied to measurement of the concentrations of linezolid and tedizolid. This simple method, which can simultaneously quantify both drug concentrations for daily TDM, could contribute to safer treatment of patients.

In therapeutic drug monitoring of vancomycin (VCM), the area under the concentration-time curve (AUC) is related to clinical efficacy and toxicity. Determining the maintenance for patient is necessary since VCM concentrations are affected by factors such as renal function. We constructed a machine learning-based model to estimate the maintenance dose to target an AUC of 400-600 mg⋅h/L in each combination of patient's factors. This retrospective observational study was conducted at two hospitals. Patients who received VCM intravenously with measured trough and another point (e.g., peak) concentrations within the November 2011 to March 2019 period were enrolled. We extracted the factors that affect VCM concentration and constructed a decision tree model using a classification and regression tree algorithm. Of the 1380 patients, 822 were included. Training data were split up to four times and included 24 subgroups. The average corrected VCM daily doses ranged 17.6-59.4 mg/kg. Estimated glomerular filtration rate, age, and body mass index were selected as predictive variables that affected the recommended daily dose. In the validation data, our model had slightly higher proportions of AUC of 400-600 mg⋅h/L than other nomograms. However, our model was based only on limited patients. Thus, further clinical studies are needed to develop a general-purpose model in the future. We successfully constructed a model that recommends VCM maintenance daily doses with AUC of 400-600 mg⋅h/L for each combination of independent variables. Our model has the potential for application as a simple decision-making tool for medical staff.

Chemotherapy regimen management is one of the most important oncology pharmacy practices, because chemotherapy is conducted according to the registered regimens. In this study, we evaluated the pharmaceutical practice that assumes the initial confirmation of chemotherapy regimens and the quality of practice sharing between oncology-specialized and non-specialized pharmacists in regimen management committee. Pharmacists initially confirmed the applied regimen prescribed by physicians regarding chemotherapeutic agents and prophylactic supportive care medicines. Following confirmation, the regimens were reviewed by the Hokkaido University Hospital Regimen Management Committee. A total of 233 regimens were reviewed by the committee over three years. In total, 110 pharmaceutical inquiries were conducted, 45% of inquiries were concerning chemotherapeutic agents, of which approximately half were regarding supportive care medicines. Most inquiries were regarding premedication, followed by those on administration time, solvent of infusion medicines, and dosage. Correction was performed for 84.5% of inquiries. There was no significant difference in inquiry rates between practice and trial regimens. We have entrusted the first basic regimen review according to the checklist, creation of the chemotherapy plan document, and registry of the adopted regimens in the ordering system from oncology-certified pharmacists to non-certified pharmacists. Basic regimen review was well conducted by a non-certified pharmacist, and a more advanced review was additionally performed by certified pharmacists. In conclusion, we demonstrated the utility of pharmaceutical confirmation in a chemotherapeutic regimen review, suitable review coverage, and quality practice sharing between oncology-certified and non-certified pharmacists, which is one of the recommended methods in chemotherapy regimen review.

CT-P6 is a biosimilar of trastuzumab and is recommended to be administered for 30-90 min in subsequent maintenance infusions to prevent infusion-related reactions (IRRs). We administered CT-P6 for 30 min as the first injection and as an alternative to reference trastuzumab in the maintenance infusion and evaluated the safety of the administration. A total of 140 patients with breast or gastric cancer, who received a switch from tri-weekly reference trastuzumab to CT-P6 for 30 min in maintenance infusions, were retrospectively evaluated. Premedication was administered prior to an infusion of CT-P6 and a cytotoxic agent. However, premedication was not provided when CT-P6 was co-administered with pertuzumab or administered alone. The primary endpoint was the incidence of IRRs. The secondary endpoint was the incidence of diarrhea and skin toxicity. Ninety-five percent of the patients had breast cancer, and 44.3% had advance-stage cancer. The treatment included CT-P6 alone (17.9%) or with cytotoxic agents (23.6%), antihormonal drugs (25.7%), and pertuzumab (62.9%). Median administration time of trastuzumab at the switch was 13 administrations (range 2-140). Premedication was administered to 20.7% patients. One patient (0.7%) experienced grade 3 IRR. The frequency of diarrhea in the reference trastuzumab group and the CT-P6 group was 7.1 and 6.4%, respectively, and that of skin toxicity was 6.4 and 5.0%, respectively, without differences. In conclusion, we first demonstrated that an initial CT-P6 administration for 30 min during the switch from reference trastuzumab in maintenance infusion is an acceptable administration method.

A major adverse effect of benzbromarone is hepatotoxicity. Therefore, periodic liver function tests are required at least for the first 6 months of benzbromarone administration. However, it is not clear whether the relevant blood tests are implemented appropriately. Here, we performed a cross-sectional survey of the implementation status of liver function tests in patients who were newly prescribed benzbromarone, using the Japanese large claims database. Male patients who were newly prescribed benzbromarone from January 2010 to December 2016 were included. We targeted patients who continued benzbromarone during the observation period (up to 180 d from the start of administration). The primary endpoint was the proportion of patients in whom periodic liver function tests were implemented. A periodic liver function test was defined as one or more liver function tests performed during both 1-90 and 91-180 d of initial benzbromarone administration. We labeled the tests as a "periodic test" or "non-periodic test" based on whether periodic liver function tests were performed or not, respectively. Furthermore, factors influencing non-periodic test were analyzed. Periodic testing was implemented only in 28.7% of patients. Additionally, factors such as number of hospital beds ≤19 (compared to 100-199 beds) and duration of the first prescription of benzbromarone were associated with non-periodic testing. Our study revealed that periodic liver function tests are not performed sufficiently in Japan. Thus, clinicians prescribing benzbromarone should be educated about the test. Our blood-test-based approach should be applied to other drugs and countries in future research.

Antibiotic-associated diarrhea (AAD) is a typical side effect of antibiotic treatment, especially in children. Amoxicillin (AMPC) and amoxicillin/clavulanate (AMPC/CVA) are associated with high risk of AAD; however, these antibiotics are important in the pediatric field. Recent research suggests that probiotics prevent pediatric AAD, including that caused by AMPC and AMPC/CVA. Indeed, guidelines for acute otitis media in children recommend the concomitant use of probiotics. However, the prescription status of probiotics for pediatric patients with otitis media receiving oral AMPC and AMPC/CVA remains unknown. We therefore conducted a survey to clarify the current status of these prescriptions and, in particular, to identify specific populations with a low proportion of probiotic prescriptions. Pediatric patients (≤15 years of age) newly prescribed oral AMPC or AMPC/CVA for otitis media between April 2016 and March 2017 were identified from a Japanese health insurance claims database. Eligible patients were divided into the AMPC (1303 patients) and AMPC/CVA (424 patients) groups, in which 659 (50.6%) and 293 (69.1%) patients were prescribed probiotics, respectively. Of the patients receiving probiotic prescriptions in the AMPC and AMPC/CVA groups, 632 (95.9%) and 286 (97.6%) patients received antibiotic-resistant probiotic prescriptions, respectively. When classified by the prescribing clinical department and patient age, the proportions of probiotic prescriptions in Internal Medicine and Pediatrics departments were lower than those in the Otorhinolaryngology department regardless of age. These results indicate the probability of insufficient probiotic prescriptions for pediatric patients with otitis media. Solving this issue may lead to the provision of safer antimicrobial therapy.

Olanzapine is effective for schizophrenia management; however, it is contraindicated in diabetes patients. In addition, olanzapine is useful for treating nausea and vomiting, such as in the case of chemotherapy-induced nausea and vomiting (CINV). Therefore, we hypothesized that the contraindicated prescription of olanzapine likely occurs among cancer patients with diabetes, especially by non-psychiatric physicians. Hence, we conducted a nationwide survey to elucidate the situation of such contraindicated prescriptions and the associated risk factors. We extracted the data of patients who were newly prescribed olanzapine between April 2015 and March 2017 from the health insurance claims database developed by JMDC, Inc., Tokyo. The patients who were prescribed contraindicated olanzapine were defined as those who were prescribed olanzapine after a diagnosis of diabetes and diabetes drug prescription. In all, the data of 7181 patients were analyzed. We evaluated the proportion of diabetes patients who were prescribed contraindicated olanzapine from among those who were prescribed olanzapine. Furthermore, we investigated the background of patients who were prescribed olanzapine for information such as olanzapine prescribers and history of cancer chemotherapy. In all, 100 diabetes patients (1.39%) were prescribed olanzapine. In these patients, the frequency of olanzapine prescription was higher by non-psychiatry/neurology physicians than by psychiatry/neurology physicians (3.25 and 0.85%, respectively). Additionally, all olanzapine prescriptions in cancer chemotherapy-treated diabetes patients were issued by non-psychiatry/neurology physicians. Thus, our study revealed there were diabetes patients who were prescribed olanzapine. Additionally, olanzapine for CINV management was more likely to be a contraindicated prescription.

Dasatinib is a first-line pharmacotherapeutic treatment for chronic myeloid leukemia (CML). It is more effective than traditional treatments but causes adverse effects such as pleural effusion that limits its effective treatment cycle. Since pleural effusion is caused by vascular hyperpermeability and causes discontinuation of treatment with dasatinib, it is important to explore the mechanism of pleural effusion caused by dasatinib and how to prevent it. In this study, we investigated how dasatinib increase vascular permeability, and how it can be prevented. Cytotoxicity was observed in vascular endothelial cells or epithelial cells were exposed to high concentrations of dasatinib. Thus, it was observed in vascular endothelial cells such as human umbilical vascular endothelial cell (HUVEC). Vascular endothelial (VE)-cadherin is one of the important factors that control vascular permeability. When VE-cadherin expression decreases, vascular permeability increases, but it did not change with tyrosine kinase inhibitor exposure. Monolayer permeability significantly increased only with high concentration of dasatinib, but this increase was prevented by cAMP activation. Furthermore, dasatinib affects the cell morphology of HUVEC, with increased inter celluar space compared to control and bosutinib, which were also attenuated by cAMP activation. Dasatinib significantly affected permeability control of vascular endothelial cells compared to bosutinib and imatinib. These results indicated that the cAMP signaling pathway may be involved in the pleural effusion caused by dasatinib in CML patients.

Nausea is a typical adverse event associated with opioids. In this study, we performed logistic regression analysis with the aim of clarifying the risk factors for nausea induced by extended-release oxycodone (ER-OXY). Furthermore, we constructed a decision tree (DT) model, a typical data mining method, to estimate the risk of oxycodone-induced nausea by combining multiple factors. A retrospective study was conducted on patients who newly received ER-OXY for cancer pain during hospitalization at Hokkaido University Hospital in Japan from April 2015 to March 2018. In logistic regression and DT analyses, the dependent variable was the presence or absence of nausea. Independent variables were the potential risk factors. First, univariate analyses were performed to screen potential factors associated with oxycodone-induced nausea. Then, multivariate and DT analyses were performed using factors with p-values <0.1 in the univariate analysis. Of 267 cases included in this study, nausea was observed in 30.3% (81/267). In multivariate logistic regression analysis, only female sex was extracted as an independent factor affecting nausea (odds ratio, 1.98). In the DT analysis, we additionally revealed that an age <50 years was a risk factor for nausea in female patients. Thus, our DT model indicated that the risk of ER-OXY-induced nausea was highest in the subgroup comprising females <50 years of age (66.7%) and lowest in male patients (25.1%). The DT model suggested that the factor of young women may be an increased risk of ER-OXY-induced nausea.

We have reported that a strict denosumab administration management system with oral calcium/vitamin D supplementation attenuates denosumab-induced hypocalcemia in 158 cancer patients with bone metastasis. In this report, 27.8% of the patients experienced hypocalcemia, including 0.6% with grade 2. So far, the risk factors for ≥grade 2 hypocalcemia incidence have been identified in denosumab-treated cancer patients, including patients without calcium/vitamin D supplementation. Therefore, the present study aimed to reveal the factors that affect all-grade hypocalcemia incidence with calcium/vitamin D supplementation and team medical care according to the management system. A receiver operating characteristic curve analysis suggested that the cutoff of baseline serum calcium level for all-grade hypocalcemia incidence was 9.3 mg/dL. Multivariate analysis revealed that age ≥65 years (odds ratio, 95% confidence interval: 2.57, 1.11-5.95, p = 0.03), grade 1 or higher serum alkaline phosphatase elevation (3.70, 1.71-8.00, p < 0.01), an adjusted serum calcium level of less than 9.3 mg/dL (3.21. 1.25-8.24, p = 0.02) at baseline, and co-administration of cytotoxic agents (2.33, 1.06-7.11, p = 0.03) are risk factors for the incidence of all-grade hypocalcemia. However, renal dysfunction, which has been suggested to be a risk factor in previous reports, was not a factor. In conclusion, we revealed the risk factors for all-grade hypocalcemia in calcium/vitamin D supplementation and awareness, as demonstrated by the management system. Moreover, renal dysfunction was not a risk factor in our strict denosumab administration management system. Our results support the value of early detection of hypocalcemia incidence to guide the selection of an appropriate management strategy.

The currently approved dose of pazopanib (800 mg) is being re-examined owing to its adverse effects. The aim of this study was to evaluate the relationships among starting or maintenance doses of pazopanib, estimated pazopanib C min , and other clinical factors, including albumin and α-1 acid glycoprotein levels, in soft-tissue sarcoma and renal cell carcinoma. We also determined whether therapeutic drug monitoring of pazopanib concentrations may be used to improve its therapeutic efficacy and prevent adverse effects. Forty patients who received pazopanib for renal cancer or soft-tissue sarcoma at the Hokkaido Cancer Center were evaluated prospectively. C min for pazopanib was calculated based on the measured values from the plasma samples. The efficacy and time to treatment failure were then assessed. The pazopanib maintenance doses were 200 (n = 4), 400 (n = 34), 600 (n = 4), and 800 mg (n = 1). Most patients (65%) who received a 400 mg dose had an effective pazopanib concentration (≧20 µg/mL), whereas 35% of patients who received the 400 mg dose had ineffective concentrations (<20 µg/mL). Logistic regression analysis revealed that only the albumin level was significantly associated with effective pazopanib concentrations (odds ratio: 1.37, p = 0.0234). In conclusion, a dose of 400 mg had been effective and well tolerated in more than half of patients in this study. However, therapeutic drug monitoring is necessary during pazopanib therapy.

This study aimed to construct an optimal algorithm for initial dose settings of vancomycin (VCM) using machine learning (ML) with decision tree (DT) analysis. Patients who were administered intravenous VCM and underwent therapeutic drug monitoring (TDM) at the Hokkaido University Hospital were enrolled. The study period was November 2011 to March 2019. In total, 654 patients were included in the study. Patients were divided into two groups, training (patients who received VCM from November 2011 to December 2017; n = 496) and testing (patients who received VCM from January 2018 to March 2019; n = 158) groups. For the training group, DT analysis of the classification and regression tree algorithm was performed to construct an algorithm (called DT algorithm) for the initial dose settings of VCM. For the testing group, the rates of attaining the VCM therapeutic range (trough value = 10-15 and 10-20 mg/L) with the DT algorithm and three conventional dose-setting methods were compared for model evaluation. The DT algorithm was constructed to be used for patients with estimated glomerular filtration rate ≥50 mL/min and body weight ≥40 kg. As a result, the recommended daily doses ranged from 20.0 to 58.1 mg/kg. In model evaluation, the DT algorithm obtained the highest rates of attaining the VCM therapeutic range compared to conventional dose-setting methods. Therefore, our DT algorithm can be applied to clinical practice. In addition, ML is useful for setting drug doses.

We previously reported that successive pharmaceutical care by oncology pharmacy specialists contributes to quality outpatient chemotherapy. However, there are a few reports regarding such care during immune checkpoint inhibitors (ICIs) treatment, despite increasing patients being treated with ICIs and the profile of immune-related adverse events being quite different from that of the adverse effects of cytotoxic agents. We retrospectively evaluated the effectiveness of continuous pharmaceutical care in outpatient ICI treatment, focusing especially on the period of providing pharmaceutical recommendations. The adoption rate, efficacy, and period of pharmaceutical interventions, such as prescription questions and pharmaceutical recommendations, were evaluated. A total of 3597 ICI administrations (366 patients) were evaluated. We performed 2625 face-to-face medication counseling. A total of 282 prescription questions and 147 pharmaceutical recommendations were conducted. Approximately 70% of the questions were regarding ordering of laboratory examination, and 86.5% of these questions were adopted. Pharmaceutical recommendations were categorized into medication recommendations (81.1%), examination recommendations (10.8%), and recommendation of expert consultation (8.1%). The adoption rate of pharmaceutical recommendations was 96.0, and 70% of the medication recommendations attenuated the symptoms. Finally, the provision rate of pharmaceutical recommendations was significantly higher in the first 3 months after ICI treatment initiation. We found that pharmaceutical care contributes to an improved quality of outpatient ICI treatment, and face-to-face pharmaceutical counseling up to 3 months after ICI treatment initiation is the most important.

The anti-inflammatory agent colchicine may cause toxic effects such as rhabdomyolysis, pancytopenia, and acute respiratory distress syndrome in cases of overdose and when patients have renal or liver impairment. As colchicine is a substrate for CYP3A4 and P-glycoprotein (P-gp), drug-drug interactions are important factors that cause fatal colchicine-related side effects. Thus, we conducted a nation-wide survey to determine the status of inappropriate colchicine prescriptions in Japan. Patients prescribed the regular use of colchicine from April 2014 to March 2017 were identified using the Japanese large health insurance claims database. As the primary endpoint, we evaluated the concomitant prescription proportions of strong CYP3A4 and/or P-gp inhibitors classified as "contraindications for co-administration" with colchicine in patients with renal or liver impairment. We defined these cases as "inappropriate colchicine prescriptions." Additionally, factors affecting inappropriate colchicine prescriptions were analyzed. Among the 3302 enrolled patients, 43 (1.30%) were inappropriately prescribed colchicine. Of these 43 patients, 11 had baseline renal and/or liver impairment. By multiple regression analysis, the primary diseases "gout" and "Behçet's disease" were extracted as independent factors for inappropriate colchicine prescriptions with odds ratios of 0.40 (95% confidence interval: 0.19-0.84) and 4.93 (95% confidence interval: 2.12-11.5), respectively. We found that approximately 1% of patients had important colchicine interactions. Particularly, Behçet's disease was a risk factor for inappropriate prescriptions, with approximately 25% of patients showing renal and/or liver impairment (classified as "contraindications for co-administration"). These findings may be useful for medical professionals who prescribe colchicine therapy.

Tyrosine kinase inhibitors (TKIs) are used as the first choice for chronic myeloid leukemia (CML) pharmacotherapeutics. Some patients taking these drugs showed good therapeutic reactivity despite the disappearance of drugs from blood. We investigated whether these drugs have sustained effects even after their disappearance and whether their effects depend on their amounts of intracellular accumulation. Cell proliferation after exposure of K562 cells or Multidrug resistance-1 (MDR-1)-transfected K562 cells was determined by a cell counting kit-8 assay. The intracellular accumulation amount of the drug showing a sustained cytostatic effect was measured by ultra high performance liquid chromatography mass spectrometry. Cell viability decreased in a culture time-dependent manner after washing out nilotinib and dasatinib. The sustained cytostatic effect of dasatinib, but not that of nilotinib, correlated with the intracellular accumulation level. In contrast, imatinib showed continuous a cytostatic effect after drug washout for long-term exposure but not after drug washout for short-term exposure. These results suggest that a good response in patients with a low serum concentration of imatinib, nilotinib or dasatinib may be due to the cytostatic effect of that drug continues even after its disappearance in plasma.

Olfactory bulbectomized (OBX) mice are characterized by impaired performance in the passive avoidance test and decreased number of cholinergic neurons in the hippocampus. Several studies have reported that κ-opioid receptor agonists improve cognitive function in mice. However, their influence on OBX-induced cognitive dysfunction remains unclear. To address this question, we evaluated the effects of the endogenous κ-opioid receptor agonist dynorphin A (Dyn A) and the selective agonist trans-(-)-U-50488 on the behavior of OBX mice in the passive avoidance test. The cognitive dysfunction of OBX mice was significantly recovered by the intracerebroventricular administration of Dyn A or trans-(-)-U-50488. The effects of these two agonists were counteracted by the selective κ-opioid receptor antagonist nor-binaltorphimine or the inhibitor of acetylcholine release β-bungarotoxin. These findings suggest that κ-opioid receptor agonists produce anti-dementia effects through activation of cholinergic neurons in OBX mice.

Dietary and biliary cholesterol absorption contributes to the maintenance of tight control of cholesterol homeostasis. Cholesterol is present as mixed micelles formed by bile salts and phospholipids in the intestinal lumen. Recently, Niemann-Pick C1-Like 1 (NPC1L1) transporter was identified as being critical for cholesterol absorption. However, the uptake mechanism of an enveloped substrate of NPC1L1 in whole lipid emulsion particles remains unclear. In this study, we investigated the uptake mechanism of a substrate of NPC1L1 in lipid emulsion particles. We also investigated whether these particles containing cholesterol can improve the intestinal absorption of other lipophilic components via NPC1L1. The uptake of lysophosphatidylcholine (LPC)-4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-propionic acid saccinimidyl ester (BODIPY), a fluorescently labeled phospholipid, in lipid emulsion particles containing cholesterol (1 µM) was significantly increased compared to that without cholesterol in Caco-2 cells. On the other hand, its increased uptake was significantly inhibited by ezetimibe, a selective inhibitor of NPC1L1. These results suggested that not only cholesterol but also some components in lipid emulsion particles are taken up into enterocytes via NPC1L1. We also examined an approach to improve intestinal absorption of a poorly absorbed water-insoluble component, coenzyme Q10 (CoQ10), by this mechanism. The uptake of CoQ10 in lipid emulsion particles containing cholesterol was significantly increased compared to that without cholesterol. Its increased uptake was significantly inhibited by ezetimibe. Though it is still not clear whether CoQ10 is a substrate of NPC1L1, there is a potential for improvement of the absorption of poorly absorbed components by lipid emulsion particles containing cholesterol.

Combination chemotherapy is often used to treat cancer. Many studies have shown schedule-dependent effects between anticancer drugs. Our previous studies showed that K-562 cells pretreated with non-cytotoxic concentrations of 4-hydroperoxycyclophosphamide (4-HPC), which is a preactivated analog of cyclophosphamide (CY), enhanced the cytotoxicity of etoposide (VP-16). The appearance of cellular resistance to anticancer drugs is a major problem in cancer chemotherapy. P-Glycoprotein (P-gp) plays an important role in drug resistance, and VP-16 is a substrate for this efflux pump. In the present study, we demonstrated schedule-dependent cytotoxicity of VP-16 and CY in P-gp-overexpressed K-562/P-gp cells. Cytotoxicity of VP-16 was enhanced in K-562/P-gp cells that were pretreated with a non-cytotoxic concentration of 4-HPC compared to that of cells not treated with 4-HPC. 4-HPC arrested the cell cycle at S phase. Cells in S phase are most sensitive to VP-16. The results suggest that cell cycle arrest by 4-HPC pretreatment may be responsible for the enhanced cytotoxicity of VP-16. The findings in this study should lead to improvements in clinical combination chemotherapy.

Coenzyme Q10 (CoQ10) is an essential component in the electron-transport systems of mitochondria and bacteria and is often used as a supplementary treatment for some diseases. We previously reported that the bioavailability of CoQ10 powder was less than 10%. In this study, we investigated various preparations to improve the intestinal absorption of CoQ10 with focus on the effect of emulsification. We prepared a suspension and some emulsions with four types of surfactants and investigated the plasma concentration profile after oral administration to rats. The absorption of CoQ10 was improved by an emulsion formulation although there was little absorption of CoQ10 when a suspension was administered. However, little CoQ10 was absorbed in the bile duct-ligated group even when the emulsion formulation was administered (about 50% of the control group). Bile and emulsion formulation are essential for absorption of CoQ10. When the preparations containing Tween20 (polysorbate (20) sorbitan monolaurate) and Tween80 (polyoxyethylene (20) sorbitan monooleate) were administered, plasma concentrations of CoQ10 were higher than those obtained with preparations containing Tween65 (polyoxyethylene (20) sorbitan tristearate) and Span20 (sorbitan monolaurate). Tween20 and Tween80 have higher hydrophile-lipophile balance (HLB) values than those Tween65 and Span20. Our study suggests that highly lipophilic compounds like CoQ10 would diffuse the unstirred water layer and would easily access the intestinal apical membrane by an emulsion containing a surfactant with a high HLB value. Attention must be given to CoQ10 supplementation for patients whose bile is not excreted to the intestine such as patients with cholestasis.

Carvedilol is administered orally as a racemic mixture of R(+)- and S(-)-enantiomers for treatment of angina pectoris, hypertension and chronic heart failure. We have reported that enzyme kinetic parameters for carvedilol glucuronidation by human liver microsomes (HLM) differed greatly depending on the substrate form, namely, racemic carvedilol and each enantiomer. These phenomena were thought to be caused by mutual inhibition between carvedilol enantiomers during racemate glucuronidation. The aim of this study was to clarify the mechanism of these phenomena in HLM and human intestinal microsomes (HIM) and its relevance to uridine 5'-diphosphate (UDP)-glucuronosyl transferase (UGT) 1A1, UGT2B4 and UGT2B7, which mainly metabolize carvedilol directly in phase II enzymes. HLM apparently preferred metabolizing (S)-carvedilol to (R)-carvedilol in the racemate, but true activities of HLM for both glucuronidation were approximately equal. By determination of the inhibitory effects of (S)-carvedilol on (R)-carvedilol glucuronidation and vice versa, it was shown that (R)-carvedilol glucuronidation was more easily inhibited than was (S)-carvedilol glucuronidation. UGT2B7 was responsible for (S)-carvedilol glucuronidation in HLM. Ratios of contribution to (R)-carvedilol glucuronidation were approximately equal among UGT1A1, UGT2B4 and UGT2B7. However, enzyme kinetic parameters were different between the two lots of HLM used in this study, depending on the contribution ratio of UGT2B4, in which (R)-glucuronidation was much more easily inhibited by (S)-carvedilol than was (S)-glucuronidation by (R)-carvedilol. Meanwhile, HIM preferred metabolizing (R)-carvedilol, and this tendency was not different between the kinds of substrate form.

In allogeneic bone marrow transplantation (allo-BMT) in patients with leukemia, the combination of VP-16 and cyclophosphamide (CY) is commonly used for the conditioning regimen. In the present study, we demonstrated schedule-dependent cytotoxicity of VP-16 and CY in K-562 cells. K-562 cells were pretreated with low concentrations (2.5 and 5 µg/mL) of 4-hydroperoxycyclophosphamide (40487S), which is a preactivated analog of CY. It was confirmed that these concentrations did not influence cell viability. Cells subsequently exposed to 0.5-100 µg/mL of VP-16 showed reduced the viability compared to that of control cells not treated with 40487S. In contrast, there was no change in the viability of K-562 cells pretreated with low concentrations (0.5 and 1 µg/mL) of VP-16. It was confirmed that these concentrations did not influence cell viability. Viability of subsequently exposed to 1-20 µg/mL was not different from that of control cells not treated with VP-16. VP-16 caused cell cycle arrest at G₂/M phase. On the other hand, 40487S arrested the cell cycle at S phase. Thymidine-synchronized cells, VP-16 showed cell cycle specificity for cell killing from early-S to mid-S phase. On the other hand, 40487S showed cell cycle-independent cytotoxicity. Exposure of cells to VP-16 after 40487S induced a greater cytotoxic effect on K-562 cells. The findings may lead to improvements in clinical combination chemotherapy.

Ischemia-reperfusion (I/R) injury of the intestine is an important factor associated with high rates of morbidity and mortality. Intestinal I/R is a common clinical problem in the settings of severe burns, circulatory shock and strangulation ileus. Intestinal I/R damages remote organs and promotes multi-organ failure. It has been shown that enteral feeding before ischemic insults is beneficial for reducing organ injury and improving survival after intestinal I/R. In that study, the authors used a standard complex enteral diet and they suggested that it is important to find new nutrient formulas. Since reactive oxygen species are responsible for intestinal I/R injury, we focused on a dietary polyphenol, the soy isoflavone genistein. Genistein has a wide spectrum of biochemical and pharmacological activities. However, the possibility of a protective effect of genistein as enteral nutrition on I/R injury has not been investigated. We therefore investigated the protective effect of genistein on oxidative injury using intestinal I/R model rats. We found that genistein, which has combined antioxidant activity from radical scavenging, xanthine oxidase inhibition and chain-breaking effects, exhibits a protective effect on intestinal I/R injury. The results suggest that genistein, a soy isoflavone, has the possibility as a new nutrient formula of enteral feeding.

5-Fluorouracil (5-FU)-based chemotherapies with irinotecan have been applied for the treatment of cancers, and a common dose-limiting toxicity is neutropenia and diarrhea. In this study, we investigated the effect of 5-FU treatment on expression levels of drug transporters for SN-38 transportation and SN-38 absorption from the intestine following 5-FU treatment. Expression levels of several drug transporters and nuclear receptors in rats after 5-FU treatment were evaluated. SN-38 absorption from the intestine was evaluated by SN-38 concentration levels in serum following SN-38 injection into the intestine of 5-FU treated rats. The levels of renal multidrug resistance protein 2 (Mrp2) on day 4 after treatment (400 mg/kg) showed significant upregulation, 359.2 ± 33.2% (mean ± S.E.) of control. Mrp2 levels in the intestine were downregulated to 26.2 ± 8.4% of control. 5-FU treatment (400 mg/kg) also significantly downregurated expression levels of P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) to 41.2 ± 14.7%, 15.7 ± 4.3% of control, respectively. To evaluate SN-38 absorption from the intestine, SN-38 was loaded in to the intestine on day 4 after 5-FU treatment. Pretreatment with 5-FU significantly increased SN-38 concentration in the blood 30, 60 and 90 min after SN-38 administration. The area under the curve for SN-38 in the 5-FU group was significantly higher than in vehicle groups. 5-FU treatment decreased expression levels of P-glycoprotein and Bcrp in intestine. The present study suggests that combination chemotherapy of 5-FU with irinotecan (CPT-11) may elevate SN-38 absorption from intestine.

Sorafenib and sunitinib is a small molecule inhibitor of certain receptor tyrosine kinases, and have improved outcomes for patients with advanced renal cell carcinoma. Inhibitory concentration of 50% cell growth of sorafenib significantly rose to 6.4-fold in a multidrug resistance protein 2 (MRP2) transfected cell line versus control cell line. The concentration of sorafenib was significantly decreased to 74% of control cells after 3 h treatment. In contrast, a tyrosine kinase inhibitor sunitinib did not show alteration of inhibitory concentration of 50% cell growth and accumulation into the cells of MRP2 transfected cells. The present study suggest that sorafenib is a substrate for MRP2, suggesting that MRP2 may implicate drug resistance to sorafenib.

Carvedilol, an alpha- and beta-adrenergic blocking drug, is mainly metabolized by CYP2D6, UGT1A1, UGT2B4 and UGT2B7. This drug is administered orally as a racemic mixture of R(+)- and S(-)-enantiomers. It has been reported that CYP2D6 prefers metabolizing S-carvedilol to R-carvedilol stereoselectively. On the other hand, stereoselective metabolism of carvedilol by UGTs is still unclear. Moreover, we have reported that patients with chronic heart failure who had polymorphism in CYP2D6, UGT1A1 and/or UGT2B7 had lower metabolic activity and oral clearance than did patients with no polymorphism. The aim of this study was to clarify stereoselective metabolism of carvedilol by UGT1A1 and UGT2B7 and to determine by using a recombinant enzyme-introduced mutation whether genetic mutation in UGT1A1 and UGT2B7 causes reduction in metabolic activity for carvedilol. A glucuronidation assay using human liver microsomes and recombinant UGT1A1 and UGT2B7 expressed in HeLa cells demonstrated that UGT1A1 prefers metabolizing R-carvedilol to S-carvedilol. On the other hand, UGT2B7 prefers metabolizing S-carvedilol to R-carvedilol. Moreover, G71R mutation of UGT1A1 reduced both affinity and capacity but did not affect stereoselective metabolism. On the other hand, both A71S and H268Y mutations of UGT2B7 reduced capacity but did not affect affinity and, as a result, the efficiency of metabolism was remarkably reduced. However, as in the case of UGT1A1, neither of the mutations affected stereoselective metabolism.

In our previous study it was observed that the frequencies of UGT1A1*6, UGT2B7*3 and CYP2D6*10 in patients who have a low level ability of glucuronidation were significantly higher than those in patients with a high level of ability of glucuronidation. The same tendency was found in the frequency of CYP2D6*5, though there was no significant difference. The purpose of this study was to evaluate the effects of the polymorphism on pharmacokinetics of carvedilol by population pharmacokinetic analysis. Population pharmacokinetic analysis was performed using 373 plasma concentrations from 41 patients with chronic heart failure or angina pectoris. A one compartment pharmacokinetic model with first-order absorption (for oral dosing) was used to describe the concentration-versus-time data for carvedilol. We examined the effects of various clinical and genetic covariables in the regression models for clearance and volume of distribution. The results suggested that the factors of interindividual variation for carvedilol clearance were creatinine clearance and polymorphisms of UGT2B7 and CYP2D6 in the Japanese population with heart disease. It was estimated that UGT2B7*3 decreased the clearance of carvedilol by 37%, but UGT2B7*2 did not show any effect. Clearance in the patients who have intermediate activity of CYP2D6 was decreased by 39%.

We previously reported that small intestinal motility was significantly inhibited by restraint stress, but not by footshock stress. In the present study, we found that plasma beta-endorphin levels were more significantly elevated by footshock stress than restraint stress, and that preloading of footshock stimulus canceled the inhibition of small intestinal motility by restraint stress. Pretreatment with the mu-opioid receptor antagonist naltrexone significantly attenuated this canceling effect of footshock stimulus. These results suggest that footshock stimulus may cancel the inhibition of small intestinal motility by restraint stress via activation of mu-opioid receptors.

We have reported that acute restraint stress inhibits small intestinal motility in rats. In order to clarify this inhibitory mechanism, we examined the effects of alpha- and beta-adrenergic antagonists on the inhibition of small intestinal motility induced by restraint stress. This inhibition underwent recovery by propranolol (beta1/beta2-antagonist) or SR59230A (beta3-antagonist), but not by atenolol (beta1-antagonist), ICI-118,551 (beta2-antagonist), prazosin (alpha1-antagonist) or yohimbine (alpha2-antagonist). These results suggest that beta3-adrenoceptors play an important role in the inhibition of small intestinal motility caused by restraint stress.

The effect of two different stress stimuli, restraint stress and footshock stress, on small intestinal motility was evaluated by a more reliable method with improvement of the previous method using a radionuclide, 51Cr. The small intestinal transit was significantly inhibited by restraint stress, but not by footshock stress, although plasma corticosterone levels were significantly elevated to the same extent by restraint stress and footshock stress. These results suggest that restraint stress and footshock stress stimuli influence small intestinal motility via different mechanisms, but the reason for the difference is unclear. This experimental system using 51Cr seems to be useful for the elucidation of mechanisms for restraint stress-induced dysfunction of small intestinal motility because of its excellent quantitative evaluation of small intestinal transit.

The effect of membrane surface potential of the apical side on the intracellular uptake of ionic compounds was investigated using the human colon adenocarcinoma cell line (Caco-2). The transepithelial transport of indolepropionic acid and tryptamine was consistent with the uptake behavior shown by rat intestinal brush-border membrane (BBM) vesicles. Imipramine, which diminished the negative charge of the membrane surface (for both Caco-2 and BBM), acted to increase the uptake of the anionic compounds, indolepropionic acid and ceftibuten, and to decrease that of tryptamine (cationic compound) by both the Caco-2 monolayer and the intestinal BBM vesicles at a pH of 7.5. These results suggest that the effects of membrane surface potential on the permeability of ionic compounds were detectable on the Caco-2 cell line as well as the BBM vesicles. On the other hand, the inhibition of H(+)-linked transport and the stimulation of the surface charge-regulated uptake of ceftibuten have occurred simultaneously on the Caco-2 cell line in the presence of imipramine. It seems that the membrane surface charge (negative) plays an important role in the transport process of ionic compounds across the intestinal epithelium.

The mechanism of the renal transport of enoxacin (ENX) has been investigated using brush-border membrane vesicles (BBMVs) isolated from the rat renal cortex. The initial rate and time-course of ENX uptake were quite dependent upon the medium pH (pH 5.5 > pH 7.5). The pH dependence was in accordance with the degree of cationic form. Carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP) affected the transient uphill transport of ENX across the renal brush-border membrane in the presence of an outward-directed H(+)-gradient. The initial uptake was saturable, and transport kinetic parameters were given for a Km and Vmax of 0.59mM and 1.37nmol/(mg protein)/30s, respectively. On the other hand, an outward H(+)-gradient (pHin = 5.5, out = 7.5) dependent uptake of ENX was partially decreased by the voltage-clamped BBMVs. Furthermore, a valinomycin-induced K(+)-diffusion potential (interior negative) was found to increase the uptake of ENX at pH 5.5, which is cationic form-rich. These results suggest that ENX uptake participates in not only the H+/organic cation antiport system for organic cation secretion but also the ionic diffusion potential (interior negative) dependent permeation through the membrane.