Paliperidone-Induced Acute Hyperglycemia Is Caused by Adrenaline Secretion via the Activation of Hypothalamic AMP-Activated Protein Kinase.

Although paliperidone-related hyperglycemia has been extensively examined, the underlying mechanisms have not yet been elucidated. We investigated the effects of a single intravenous injection of paliperidone (0.2, 0.4, or 0.6 mg/kg) on serum concentrations of glucose and other endogenous metabolites in rats. We also examined the effects of a single intravenous injection of paliperidone (0.4 mg/kg) on AMP-activated protein kinase (AMPK) activity in the hypothalamus and liver. To clarify the relationship between AMPK activity and adrenaline secretion, the effects of berberine, which inhibits hypothalamic AMPK, on paliperidone-induced hyperglycemia were assessed. Significant increases were observed in serum glucose, adrenaline, and insulin concentrations following intravenous injections of paliperidone at doses of 0.4 and 0.6 mg/kg. A propranolol pretreatment attenuated paliperidone-induced increases in serum concentrations of glucose, but not adrenaline. Significant increases were also noted in phosphorylated AMPK concentrations in the hypothalamus following the administration of paliperidone at a dose of 0.4 mg/kg. A berberine pretreatment attenuated paliperidone-induced increases in blood concentrations of glucose, adrenaline, and insulin and phosphorylated AMPK concentrations in the hypothalamus. Collectively, the present results demonstrated that an acute treatment with paliperidone induced hyperglycemia, which was associated with the effects of hypothalamic AMPK activation on the secretion of adrenaline.

Prevention of Acne-Like Eruption Caused by Panitumumab Treatment through Oral Administration of Non-steroidal Anti-inflammatory Drugs.

Acne-like eruption caused by anti-epidermal growth factor receptor (EGFR) antibodies such as panitumumab reduces treatment adherence and patient QOL; an alternative therapy is desired. Meanwhile, the usefulness of oral Non-steroidal Anti-inflammatory Drugs (NSAIDs) for acne-like eruptions caused by low-molecular-weight EGFR inhibitors such as erlotinib has been reported in the treatment of lung cancer. This study aimed to investigate whether the combined use of oral NSAIDs and panitumumab for colorectal cancer patients helps prevent acne-like eruption. We retrospectively investigated 167 colorectal cancer patients who had been treated with panitumumab for three cycles or more. The observation period was set from the start of panitumumab treatment to the end of three cycles. Within this period, the incidence and severity of acne-like eruptions were compared. A total of 59 and 108 patients were in the NSAIDs use and non-use groups, respectively, showing differences in the incidence of acne-like eruption rates (78.0 vs. 90.7%, respectively; p = 0.033). In the use group, eruption severity grades 0, 1, 2, and 3 were observed in 13, 33, 13, and 0 patients, respectively; the corresponding values in the non-use group were 10, 60, 36, and 2, respectively (p = 0.007). Oral NSAIDs may help prevent acne-like eruptions caused by panitumumab.

Interleukin 6/gp130 axis promotes neural invasion in pancreatic cancer.

BACKGROUND: Nerve invasion (N-inv) is an important prognostic factor in pancreatic ductal adenocarcinoma (PDAC). Elucidation of circulating N-inv stimulators could provide deeper insights and novel perspectives for PDAC therapy. The interleukin (IL)-6/gp130 axis was evaluated in this study as a candidate N-inv stimulator. METHODS: A human pancreatic cancer (PC) cell, Capan-1, was confirmed to have the stimulant activity of IL-6/gp130 axis through the evaluation of mRNA, cell surface protein and intracellular protein levels and chemotaxis and wound healing assay. The upregulation of IL-6/gp130 axis was evaluated using tumor-derived IL-6 level and intratumoral pSTAT3 expression in N-inv of murine sciatic nerves by intraneural injection of Capan-1 cell (N-inv model) and using resected pancreatic cancer tissue and clinical data from 46 PDAC patients. RESULTS: mRNA and protein expressions of IL-6 and IL-6 receptor were found in whole cell lysate and condition medium from PC cell. Cell surface protein expression of gp130 were clearly detected on PC cell. IL-6 promoted migration and chemotaxis of PC cell. Serum IL-6 and tumoral IL-6 mRNA levels in N-inv model mice were significantly higher than those in subcutaneous tumor mice (p = 0.004 and p = 0.002, respectively). Silencing of IL-6 and gp130 on PC cell and administration of an anti-IL-6 receptor antibody, tocilizumab, suppressed N-inv, compared to each control (p = 0.070, p = 0.118 and p = 0.122, respectively). In PDAC patients, the high-N-inv group showed poor prognosis (p =0.059) and elevated serum levels of IL-6 and C-reactive protein, synthesis of which is promoted by IL-6, compared to those in the low-N-inv group (p = 0.006 and p = 0.075, respectively). Tumoral gp130 expression at N-inv was higher than that in the primary pancreatic tumor (p = 0.026). CONCLUSION: Biological activity of IL-6/gp130 axis promoted N-inv in murine model and was upregulated in PDAC patients with severe N-inv. This study is the first evidence that the IL-6/gp130 axis offers a potential therapeutic target in PDAC with N-inv.

Meta-analysis of seven heterogeneous studies on liraglutide add-on therapy in patients with type 2 diabetes mellitus treated with insulin.

BACKGROUND AND AIMS: Clinical trials indicate the efficacy of add-on therapy using incretin-related drugs to treat type 2 diabetes mellitus (DM) inadequately controlled by insulin. However, heterogeneity exists among these studies. Baseline body mass index (BMI) accounts for the heterogeneity of add-on therapy with dipeptidyl peptidase-4 (DPP-4) inhibitors and the associated higher BMI with a lower efficacy. The efficacy of add-on therapy with glucagon-like peptide-1 (GLP-1) receptor agonists remains unclear. METHODS: We performed a meta-analysis of randomized controlled trials of ≥12 weeks reporting the endpoint of adjusted mean change in hemoglobin A1c levels (AMΔHbA1c) or hypoglycemia incidence. Patients with type 2 DM treated with insulin alone or with metformin for at least 8 weeks before the study treatment were included. The intervention group received liraglutide co-administered with insulin or a fixed-dose combination. The control group received a placebo or insulin. Covariates included five baseline parameters (HbA1c, fasting plasma glucose, BMI, type 2 DM duration, and treatment duration). RESULTS: Seven studies (2067 patients) were selected. AMΔHbA1c was -1.00% (95% confidence interval [CI]: -1.21 to -0.78, I2 = 74.7%). The odds ratio for hypoglycemia incidence was 0.97 (95% CI: 0.50-1.87, I2 = 81.9%). Covariates did not account for the heterogeneity in AMΔHbA1c or hypoglycemia incidence. CONCLUSIONS: Liraglutide add-on therapy reduced HbA1c levels without increasing hypoglycemia incidence, independent of BMI, in insulin non-responders with type 2 DM. GLP-1 receptor agonists may be more suitable than DPP-4 inhibitors for add-on therapy in patients with high BMI. REGISTRATION NUMBER: PROSPERO #CRD42021178888.

The antiplatelet effect of mirtazapine is mediated by co-blocking 5-HT2A and α2-adrenergic receptors on platelets: An in vitro human plasma-based study.

Mirtazapine (MTZ) is a noradrenergic and specific serotonergic antidepressant that has been associated with an increased risk of bleeding. However, there is insufficient evidence confirming this association. We hypothesised that 5-HT2A and α2 receptor-mediated inhibitory effects of MTZ on platelets suppress platelet aggregation and increase the risk of bleeding. In this study, we examined the antiplatelet effect of MTZ on human platelets to test our hypothesis. Blood samples for platelet aggregation tests were obtained from 14 healthy volunteers. The antiplatelet effect of MTZ was evaluated using light transmission aggregometry. MTZ significantly suppressed platelet aggregation mediated both by the synergistic interaction of serotonin (5-HT) and adrenaline and the synergistic interaction of ADP and 5-HT or adrenaline. In conclusion, MTZ exerts its antiplatelet effects by co-blocking the 5-HT2A and α2-adrenergic receptors on platelets and also suppresses platelet aggregation induced by ADP and 5-HT or adrenaline. Therefore, when MTZ is used, especially for patients with a high risk of bleeding, the significance of its use must be considered carefully. In addition, the platelet aggregation pattern by adrenaline + 5-HT, ADP + adrenaline, and ADP + 5-HT was similar between humans and mice; however, this study did not directly compare the effects of MTZ on human and murine platelets. Therefore, under the conditions for inducing platelet aggregation using adrenaline + 5-HT, ADP + adrenaline, and ADP + 5-HT, mouse platelets can be used in the evaluation of the efficacy of antiplatelet drugs in humans.

Risk Factors Associated With Unplanned Acute Care in Outpatient Chemotherapy With Oral Anticancer Drugs as Monotherapy or Combination Therapy With Injectable Anticancer Drugs.

BACKGROUND/AIM: Recently, the number of patients with cancer receiving outpatient chemotherapy using oral anticancer drugs has increased, but the currently available outpatient cancer chemotherapy is not safer than that available before. The present study aimed to identify risk factors associated with unplanned acute care (UAC) requiring outpatient chemotherapy-related consultation and hospitalisation. PATIENTS AND METHODS: We conducted a case- control study among 1,674 patients who received oral anticancer drug treatment either alone or in combination with injectable anticancer drugs at National Cancer Center Hospital East, Japan, between December 1, 2014, and November 30, 2015. RESULTS: Body mass index (BMI) was identified as a risk factor for UAC during chemotherapy. Patients with a BMI of <18.5 kg/m2, classified as underweight according to the World Health Organization classification of nutritional status, had a significantly higher risk of UAC. CONCLUSION: A low BMI immediately before the occurrence of chemotherapy-related UAC is a risk factor for adverse effects; therefore, underweight patients need more careful monitoring and supportive care.

Clinical and Tumor Characteristics of Patients with High Serum Levels of Growth Differentiation Factor 15 in Advanced Pancreatic Cancer.

We aimed to evaluate the association of circulating growth differentiation factor 15 (GDF-15) with cachexia symptoms and the biological activity of advanced pancreatic cancer (APC). Treatment-naïve patients with liver metastasis of APC or with benign pancreatic disease were retrospectively analyzed. Clinical data, blood samples, and biopsy specimens of liver metastasis were collected prior to anti-cancer treatment. Serum GDF-15 levels and multiple protein expressions in lysates extracted from liver metastasis were measured by enzyme-linked immuno-sorbent assay and reverse-phase protein array, respectively. The cut-off for serum GDF-15 was determined as 3356.6 pg/mL, the mean plus two standard deviations for benign pancreatic disease. The high-GDF-15 group was characterized as showing low Karnofsky performance status (KPS) (p = 0.037), poor Eastern Cooperative Oncology Group performance status (ECOG-PS) (p = 0.049), severe appetite loss (p = 0.011), and high serum levels of carbohydrate antigen 19-9 (p = 0.019) and C-reactive protein (p = 0.009). Tumors of the high-GDF-15 group expressed high levels of phosphorylated (p)JNK (p = 0.007) and pAkt (p = 0.040). APC patients with high serum GDF-15 showed signatures of cachexia and activation of the signaling pathways involving Akt and JNK in the tumor. This study indicated circulating GDF-15 could be associated with cachectic symptoms in APC.

Comparison of the Safety and Effectiveness of Four Direct Oral Anticoagulants in Japanese Patients with Nonvalvular Atrial Fibrillation Using Real-World Data.

Direct oral anticoagulants (DOACs) are widely used for the prevention of ischemic stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF). However, the differences in safety and effectiveness among four DOACs, dabigatran, rivaroxaban, apixaban, and edoxaban, in Japanese patients have not been clarified. Therefore, we conducted a retrospective cohort study to directly compare the safety and effectiveness among the four DOACs using the Japan Medical Data Center (JMDC) claims database. We identified 3823 patients with NVAF who started receiving a DOAC between March 2011 and June 2017. The safety outcome was major bleeding (a composite outcome of intracranial, gastrointestinal, respiratory, or renal/urinary tract bleeding) and the effectiveness outcome was the composite of ischemic stroke including transient ischemic attack (TIA) or systemic embolism. We constructed a Cox proportional hazard model to calculate the hazard ratio (HR) for all four DOAC combinations. The risk of major bleeding was significantly lower in the dabigatran group than in the apixaban group (HR, 0.55; 95% confidence interval (CI), 0.31-0.93; p = 0.03). In contrast, there was no significant difference in the risk of major bleeding among the other DOACs. In the composite risk of ischemic stroke including TIA or systemic embolism, there was no significant difference among the four DOACs. This study suggested that in the current use of DOACs in Japanese patients with NVAF, dabigatran had a significantly lower risk of major bleeding than apixaban, but there was no significant difference in effectiveness among the four DOACs.

Comprehensive Exploration of Medications That Affect the Bleeding Risk of Oral Anticoagulant Users.

Oral anticoagulants (OACs) pose a major bleeding risk, which may be increased or decreased by concomitant medications. To explore medications that affect the bleeding risk of OACs, we conducted a nested case-control study including 554 bleeding cases (warfarin, n = 327; direct OACs [DOACs], n = 227) and 1337 non-bleeding controls (warfarin, n = 814; DOACs, n = 523), using a Japanese health insurance database from January 2005 to June 2017. Major bleeding risk associated with exposure to concomitant medications within 30 d of the event/index date was evaluated, and adjusted odds ratios (aORs) were calculated using logistic regression analysis. Several antihypertensive drugs, such as amlodipine and bisoprolol, were associated with a decreased risk of bleeding (warfarin + amlodipine [aOR, 0.64; 95% confidence interval (CI): 0.41-0.98], DOACs + bisoprolol [aOR, 0.51; 95% CI, 0.33-0.80]). As hypertension is considered a significant risk factor for intracranial bleeding in antithrombotic therapy, antihypertensive drugs may suppress intracranial bleeding. In contrast, telmisartan, a widely used antihypertensive drug, was associated with an increased risk of bleeding [DOACs + telmisartan (aOR, 4.87; 95% CI, 1.84-12.91)]. Since telmisartan is an inhibitor of P-glycoprotein (P-gp), the elimination of rivaroxaban and apixaban, which are substrates of P-gp, is hindered, resulting in increased blood levels of both drugs, thereby increasing the risk of hemorrhage. In conclusion, antihypertensive drugs may improve the safety of OACs, and the pharmacokinetic-based drug interactions of DOACs must be considered.

Antiplatelet Effect of Mirtazapine via Co-blocking of the 5-HT2A and α2-Adrenergic Receptors on Platelets.

Mirtazapine (MTZ) is a noradrenergic and specific serotonergic antidepressant. MTZ is reportedly associated with an increased risk of bleeding. However, the underlying mechanism remains unclear. In this study, we investigated the antiplatelet effect of MTZ in mice via light transmission aggregometry to elucidate the mechanism of MTZ-induced bleeding. The results of the ex vivo study showed that the oral administration of MTZ (20 or 100 mg/kg) significantly suppressed platelet aggregation mediated by the synergic interaction of 5-hydroxytryptamine (5-HT) and adrenaline. Additionally, MTZ significantly suppressed platelet aggregation, mediated by the synergic interaction of ADP and 5-HT or adrenaline. Similar results were obtained in vitro, under the condition of 5-HT- and adrenaline-induced platelet aggregation. Overall, the results suggest that MTZ exerts antiplatelet effect by co-blocking 5-HT2A and α2-adrenergic receptors on platelets and suppresses platelet aggregation mediated by ADP, increased by either 5-HT or adrenaline. Thus, a detailed monitoring of bleeding is recommended for patients taking MTZ.

Survey of serious adverse events and safety evaluation of oral anticancer drug treatment in Japan: A retrospective study.

The present study assessed the safety of outpatient oral anticancer chemotherapeutic drugs by investigating the type and frequency of serious adverse effects (SAEs). Emergency hospitalization, unplanned consultations and telephone calls were investigated in 1,832 patients who received oral anticancer drug treatment at the National Cancer Center Hospital East between December 1, 2014 and November 30, 2015. Oral cytotoxic anticancer and molecular targeted drugs were administrated to 1,140 (62.2%) and 692 (37.8%) patients, respectively. A total of 52 (2.8%) SAEs were reported, with 32 (2.8%) occurring following cytotoxic anticancer drug administration and 20 (2.9%) occurring after molecular targeted drug treatment. The most common SAE was gastrointestinal toxicity. The median time to SAE occurrence was 32 days (range, 5-1,705 days). The rate of unplanned consultations and telephone calls were 5.5 and 37.9% among all patients, respectively, with skin reactions being the most common reason for unplanned consultations. SAEs often occurred early after treatment initiation. It was concluded that measures against gastrointestinal toxicity are particularly important were administering chemotherapeutic agents.

Prediction of the permeability of antineoplastic agents through nitrile medical gloves by zone classification based on their physicochemical properties.

BACKGROUND: Permeability of antineoplastic agents through medical gloves is an important factor that must be considered for the appropriate selection of gloves. However, predicting the permeability of antineoplastic agents through medical gloves based on their physicochemical properties remains difficult. Thus, this study aimed to elucidate the relationship between the physicochemical properties and permeability of antineoplastic agents through medical gloves. Additionally, we tried to predict the risk of permeation of antineoplastic agents through medical gloves based on physicochemical parameters. METHODS: Ten antineoplastic agents (carboplatin, carmustine, cisplatin, cyclophosphamide, doxorubicin, etoposide, fluorouracil, ifosfamide, oxaliplatin, and paclitaxel) with varying physicochemical properties were investigated, and their permeation rates (PRs) through nitrile medical gloves of varying thicknesses (0.05, 0.07, and 0.1 mm) were measured using a continuous flow in-line cell device. We also determined the apparent permeation clearance (CLP,app) values of the antineoplastic agents based on their PRs at 240 min (PR240) and assessed the relationship between CLP,app and physicochemical parameters [molecular weight (MW) and logarithm of octanol-water partition coefficient (LogP)]. RESULTS: The CLP,app values of the 10 antineoplastic agents through nitrile medical gloves (0.05 mm thickness) were significantly correlated with their MWs, but not their LogP values (P = 0.026 and 0.39, respectively; Spearman's rank correlation). This finding indicated that the rates of diffusion of the antineoplastic agents in the glove material showed greater effects on CLP,app than the rates of absorption into the glove surfaces within 240 min of exposure. We then classified the 10 antineoplastic agents into 3 zones (Zone A, high LogP/low MW drugs; Zone B, high LogP/high MW drugs; and Zone C, low LogP) and found that Zones A, B, and C corresponded to high (PR240 > 10 ng/min/cm2), moderate (PR240 < 10 ng/min/cm2), and low (no detectable permeation) permeation risk, respectively. CONCLUSIONS: The permeation risk of antineoplastic agents through nitrile medical gloves within the actual continuous wearing time in clinical settings could be predicted using MW and LogP values. We believe that the proposed zone classification of antineoplastic agents will be a useful tool for predicting the permeation risk of antineoplastic agents through medical gloves.

Meta-Analysis of 11 Heterogeneous Studies regarding Dipeptidyl Peptidase 4 Inhibitor Add-On Therapy for Type 2 Diabetes Mellitus Patients Treated with Insulin.

BACKGROUND: Several clinical trials have addressed the therapeutic strategy of adding dipeptidyl peptidase 4 (DPP-4) inhibitors to the treatment of type 2 diabetes mellitus (DM) inadequately controlled by insulin therapy. However, there is a high degree of heterogeneity in these studies, and the cause of which has not been identified. METHODS: We conducted a meta-analysis of randomized controlled trials, which compared the efficacy and safety of adding DPP-4 inhibitors or placebo to insulin therapy; the level of hemoglobin A1c (HbA1c) in the patients was >7.0%, and the duration of treatment was ≥8 weeks. We focused on the mean changes in HbA1c from the baseline (ΔHbA1c) and the incidence of hypoglycemia. We assumed that five baseline parameters (HbA1c, fasting blood glucose, body mass index (BMI), duration of type 2 DM, and duration of treatment) could affect ΔHbA1c. Regarding the incidence of hypoglycemia, we suspected that the heterogeneity was caused by differences in the definition of hypoglycemia among the studies. RESULTS: Data obtained from 11 studies (n = 4654 patients) were included in the analysis. The mean ΔHbA1c between the DPP-4 inhibitor and placebo groups was -0.61% (95% confidence interval (CI): -0.74 to -0.48, I 2 = 73.4%). There was substantial heterogeneity among the 11 studies, but 74.1% of this variability was explained by the difference in BMI. The odds ratio for the incidence of hypoglycemia was 1.02 (95% CI: 0.74 to 1.42, I 2 = 63.8%), with substantial heterogeneity due to differences in the definition of hypoglycemia among the studies. There was no apparent effect of publication bias. CONCLUSIONS: The addition of DPP-4 inhibitors to insulin therapy for adult patients with type 2 DM can significantly reduce HbA1c levels without increasing the occurrence of hypoglycemia. BMI and hypoglycemia definition could explain the heterogeneity in the clinical trials. This trial is registered with PROSPERO #CRD42016035994.

Evaluation of the Role of P-glycoprotein (P-gp)-Mediated Efflux in the Intestinal Absorption of Common Substrates with Elacridar, a P-gp Inhibitor, in Rats.

BACKGROUND AND OBJECTIVES: P-glycoprotein (P-gp) has been shown previously to contribute to the intestinal absorption of verapamil, diltiazem, tacrolimus, colchicine and indinavir in situ; however, its contribution in vivo is unknown. The present study aimed to evaluate the in vivo involvement of P-gp using elacridar as its inhibitor to distinguish the contribution of P-gp from cytochrome P450 (CYP) 3A. METHODS: Fexofenadine (5 mg/kg) and buspirone (1 mg/kg) were used as probe substrates of P-gp and CYP3A, respectively. Each dual substrate (1 or 2 mg/kg) was orally administered to rats after elacridar pre-treatment (3 mg/kg). Additionally, verapamil, diltiazem or tacrolimus was orally co-administered with fexofenadine. RESULTS: Elacridar drastically increased the area under the plasma concentration-time curve (AUC0-t) of oral fexofenadine by 8.6-fold; however, it did not affect the AUC0-t of oral buspirone. Therefore, elacridar inhibited P-gp without affecting CYP3A. The absorption of oral verapamil, diltiazem and tacrolimus was not influenced by elacridar pre-treatment, and the increase in the AUC0-t of fexofenadine was approximately 3-fold when co-administered with each substrate; the minimal effect of elacridar was attributable to the limited contribution of P-gp but not to their self-inhibition against the transporter. Conversely, elacridar significantly increased the AUC0-t of colchicine (5.3-fold) and indinavir (2.0-fold), indicating that P-gp contributes to their absorption. CONCLUSIONS: Elacridar is useful for distinguishing the contribution of P-gp from CYP3A to the absorption of drugs in rats. The in vivo contribution of P-gp is minimal for high permeable compounds owing to their fraction absorbed of nearly 1.0.

Investigation of Approval Trends and Benefits of New Fixed-Dose Combination Drugs in Japan.

BACKGROUND: New fixed-dose combination drugs (FDCs) had been developed in limited numbers in Japan. Since regulatory requirements were relaxed in 2005, 73 new FDCs have been approved by PMDA since 2006. In this study, we investigate trends in new FDCs and their benefits through a questionnaire survey provided to patients and pharmacists. METHODS: The new FDCs were analyzed by therapeutic categories, first approval country and drug lag (DL). Questionnaire surveys were conducted on hypertension, bronchial asthma, and glaucoma in approximately 300 patients and 700 pharmacists in 66 hospitals to investigate the benefits of new FDCs. RESULTS: The highest number of FDCs approved by the therapeutic category was 15 cardiovascular agents. The DL (median) was less than 1 year in several therapeutic categories including cardiovascular agents. The survey results showed that patient compliance improved in 30.8% of the bronchial asthma. Regarding the time and effort required to prescribe these drugs, 32.5% of pharmacists reported "slightly decreased" in bronchial asthma, while 32.0% reported "slightly increased" in hypertension. More than one-third (70.6%) responded "recommend" in bronchial asthma. CONCLUSION: The number of new FDCs markedly increased since 2006, and this presented new opportunities for the Japanese pharmaceutical industry. FDCs not only increase convenience to the patient but also improve patient compliance and the efficiency of pharmacist prescription processes. However, the rapid increase in new FDCs may cause confusion in the medical field, and new FDCs should be developed not only to improve convenience but also to consider the benefits they provide to patients, pharmacists, and physicians.

Bergamottin can be used to assess CYP3A-mediated intestinal first-pass metabolism without affecting P-glycoprotein-mediated efflux in rats.

1. We investigated whether bergamottin would be useful for evaluating CYP3A-mediated intestinal metabolism in rats utilising its characteristics as a mechanism-based inhibitor of CYP3A.2. Buspirone and fexofenadine, probe substrates of CYP3A and P-glycoprotein (P-gp), respectively, were orally co-administered to rats with bergamottin (2.5 mg/kg) or orally administered 2 h after bergamottin pre-treatment. The effect of bergamottin pre-treatment on hepatic CYP3A specifically was investigated with intravenous administration of buspirone. The kobs of bergamottin for CYP3A was calculated based on the portal unbound Cmax.3. Co-administration of bergamottin significantly increased the AUC0-inf for buspirone and fexofenadine by 1.6-fold and 1.7-fold, respectively, indicating that bergamottin inhibited both CYP3A and P-gp.4. Bergamottin pre-treatment significantly elevated the AUC0-inf of oral buspirone by 3.7-fold but exerted no effect on the pharmacokinetics of intravenous buspirone, indicating that bergamottin pre-treatment selectively inhibited CYP3A-mediated intestinal metabolism without affecting the hepatic CYP3A. These findings were supported by the result that the kobs (0.00000118 min-1) of bergamottin for CYP3A was lower than the kdeg (0.0005 min-1) for CYP3A. Furthermore, bergamottin pre-treatment did not affect the pharmacokinetics of oral fexofenadine, suggesting that P-gp was not influenced.5. These profiles of bergamottin enable the convenient assessment of CYP3A-mediated intestinal metabolism.

Usefulness of novobiocin as a selective inhibitor of intestinal breast cancer resistance protein (Bcrp) in rats.

We investigated whether novobiocin is useful for elucidating the contribution of breast cancer resistance protein (Bcrp) to intestinal absorption without affecting the activities of P-glycoprotein (P-gp), cytochrome P450 (CYP) 3 A and hepatic organic anion transporting polypeptide (Oatp) in rats.To determine the effects of novobiocin on Bcrp, P-gp, CYP3A and Oatp activities, we used sulfasalazine, fexofenadine, bosentan and midazolam, respectively, as probe substrates. Each substrate was orally or intravenously administered to rats 15 min after oral novobiocin administration at a dose of 3 mg/kg.Pre-treatment with novobiocin significantly increased the area under the plasma concentration-time curve and the peak plasma concentration of sulfasalazine after oral administration by 3.2- and 5.9-fold, respectively, in rats, whereas its systemic clearance following intravenous dosing was not influenced. These results indicate that novobiocin selectively inhibits intestinal Bcrp-mediated efflux with limited effects on extra-intestinal Bcrp activity.In addition, novobiocin pre-treatment did not significantly alter the pharmacokinetic parameters of orally administered fexofenadine and midazolam or intravenously administered bosentan, suggesting that the effects of novobiocin on other processes were negligible.These findings demonstrate that novobiocin permits estimating the net contribution of Bcrp to intestinal absorption of drug candidates.

Association of ABC Transporter With Resistance to FK866, a NAMPT Inhibitor, in Human Colorectal Cancer Cells.

BACKGROUND/AIM: Nicotinamide phosphoribosyltransferase (NAMPT), a key enzyme in the NAD+ biosynthetic pathway, is a drug target of potent anticancer candidates, including FK866 and other reported NAMPT inhibitors. However, it is known that NAMPT point-mutations render resistance to specific NAMPT inhibitors in several cancer cells. We investigated the resistance mechanisms of NAMPT inhibitor FK866 in human colorectal cancer (CRC) cells. MATERIALS AND METHODS: We used CRC human cell line HCT116 to determine the expression profiles of FK866-sensitive parental HCT116 cells and FK866-resistant HCT116 (HCT116RFK866) cells by DNA microarray analysis. The levels of multidrug resistance protein 1 (MDR1) were assessed via western blot. In addition, we analyzed the sensitivity of FK866 in parental HCT116 cells and HCT116RFK866 cells by co-treatment with MDR1 inhibitor verapamil. RESULTS: Our results revealed an association between ATP-binding cassette (ABC) transporter gene ABCB1 and resistance to NAMPT inhibitor FK866 in both HCT116RFK866 cells and parental HCT116 cells. The expression of ABCB1, which encodes MDR1, was lower in HCT116RFK866 cells than in parental HCT116 cells. Furthermore, the protein level of MDR1/ATP-binding cassette sub-family B member 1 (ABCB1) was 0.5-fold lower in HCT116RFK866 cells than in parental HCT116 cells. Additionally, HCT116RFK866 cells showed improved sensitivity to FK866 when co-treated with verapamil, an ABCB1 inhibitor. Interestingly, the efficacy of FK866 in parental HCT116 cells was the same for the treatment with FK866 alone or in combination with verapamil. CONCLUSION: The change in expression of ABCB1 plays a key role in CRC drug resistance to NAMPT inhibitor FK866. This suggests that the MDR1/ABCB1 mechanism may regulate the resistance of anticancer NAMPT inhibitor FK866.

Influence of Drug Lag on New Drug Label Revisions.

BACKGROUND: Drug lag (DL) in Japan has decreased in the last few years as a result of the globalization of drug development in the past decade, and new molecule entities (NMEs) with short DL are on the rise. The purpose of this study was to investigate the influence of DL on postmarketing safety of NMEs, by comparing the length of DL and the chronological trend of package insert revisions. METHODS: The number of label revisions occurring during 6 years after approval was investigated for 142 NMEs approved between 2000 and 2006. The NMEs were classified by the length of DL (2 years and 4 years), and the label revision trends by each label section and therapeutic categories were analyzed. RESULTS: The cumulative number of level revisions in the "Drug Interactions" and "Clinically Significant Adverse Reactions" sections in the first year after approval in the DL <2 years group was significantly greater than in the DL ≥2 years group. In the chemotherapeutic category that showed the shortest DL, the first label revision occurred in 33.3% within the first year and in 66.7% by the second year, and label revisions were performed earlier than in any other therapeutic categories. CONCLUSIONS: These results suggest that the package inserts of NMEs with a shorter DL tend to be revised earlier and more frequently, and it requires more careful monitoring of safety information after product launch.

Evaluation of the permeation of antineoplastic agents through medical gloves of varying materials and thickness and with varying surface treatments.

BACKGROUND: Medical gloves are an important piece of personal protective equipment that prevents exposure to antineoplastic agents. The permeability of medical gloves to antineoplastic agents is a crucial factor in the appropriate selection of gloves. However, the relationship between glove permeability and material type, thickness, and surface treatment is poorly understood. METHODS: A continuous flow in-line cell device was used for the evaluation of the permeation of five antineoplastic agents (etoposide, cyclophosphamide, doxorubicin hydrochloride, paclitaxel, and fluorouracil) through medical gloves. Medical gloves made of three types of materials (chlorinated latex, non-chlorinated latex, and nitrile) were subjected to a permeability test. The antineoplastic agents in test solutions were tested at the highest concentrations employed in general clinical practice. Then, the relationship between glove thickness and permeability was assessed using chlorinated latex gloves with thicknesses of 0.1, 0.15, 0.2, and 0.1 mm × 2 (to represent the practice of "double gloving"). RESULTS: Only cyclophosphamide and fluorouracil showed detectable permeation through the tested latex gloves. The permeability of chlorinated latex was lower than that of non-chlorinated latex. Nitrile gloves showed no detectable permeability to any of the five antineoplastic agents tested. The permeability of chlorinated latex gloves depended on the thickness of the gloves; 0.1 mm × 2 (double gloving) exhibited the highest resistance to permeation by antineoplastic agents. CONCLUSIONS: The permeability of medical gloves was dependent on the type of material and the surface treatment and decreased as the thickness of the glove increased. The double glove was shown to prevent antineoplastic agent permeation more efficiently than did a single glove of the same total thickness. These results provided important information that will guide the appropriate selection of medical gloves.