1.Four Possible Itching Pathways Related to the TRPV1 Channel, Histamine, PAR-2 and Serotonin
Malaysian Journal of Medical Sciences 2013;20(4):5-12
The following four possible pathways for itching sensation have been suggested by recent reports. 1) Histaminergic TRPV1-positive pathway: Although histamine-positive nerve fibers cannot strictly be classified as “itch specific” due to their excitation also by pure algogens (making them itch-selective), the existence of a subpopulation of nociceptors responsible for itching is strongly suggested. Moreover, the TRPV1-expressing neurons have been suggested to be the main sensors and mediators of itching. 2) Histaminergic TRPV1-negative pathway: The scratching behavior caused by itching was not different between capsaicin-pre-treated and vehicle-treated (control) mast cell-rich NC mice. This result suggests the existence of a capsaicin-insensitive (TRPV1-negative) histaminergic pathway. 3) Non-histaminergic PAR-2 pathway: Protease-activated receptor 2 (PAR-2) has been shown to play a role in the itching of atopic dermatitis (AD). The itch evoked by cowhage (a non-histaminergic pruritogen that activates PAR-2) is very similar in characteristics to the itch evoked by conditions such as AD. 4) Non-histaminergic serotonin (5-HT) pathway: 5-HT alone applied to the human skin evokes an itching sensation and has been suggested to be involved in the itching associated with pruritic diseases, such as polycythemia vera and cholestasis.
Pruritus
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Histamine
2.Assessments of Therapeutic Equivalence and Pharmacoeconomics of Original-Brand and Generic Drug of Glimepiride (Amaryl® vs. Glimepiride [Tanabe])
Nami Azuchi ; Kazuya Hiura ; Chinami Suzuki ; Daichi Kan ; Takumi Yukita ; Shunsuke Fuchigami ; Akina Suyama ; Takahiro Inagaki ; Takahito Imai ; Akio Shibanami ; Hiroaki Watanabe ; Yuji Kohara
Japanese Journal of Drug Informatics 2016;17(4):199-204
Objective: The use of generic drugs is promoted for the purpose of reductions of medical costs and patient’s copayment. In general, it is thought that clinical effects of the original brand and the generic drugs are equal if they are bioequivalent. However, it is necessary to inspect their therapeutic equivalence to use the generic drugs securely. We, therefore, assessed the therapeutic equivalence and pharmacoeconomics by substitution of an original drug (Amaryl®) with a generic drug (Glimepiride [Tanabe]).
Methods: Therapeutic Equivalence: The total variation was calculated by using the HbA1c levels before it switched from Amaryl® to Glimepiride [Tanabe]. The tolerance limits were set as 1/4 of the total variation. Pharmacoeconomics: The difference of drug prices and the difference of patient’s copayment were calculated.
Results: As the variation of HbA1c levels was within tolerance limits before and after switching from Amaryl® to Glimepiride [Tanabe], we evaluated that their therapeutic effect was equivalent. The difference of drug prices after switching from the original to the generic one was 4,582.6 yen/year on average (minimum: 949.0 yen, maximum: 12,045.0 yen); the difference of patient’s copayment was 872.5 yen/year on average (minimum: 0 yen, maximum: 3,613.5 yen). These data show that the use of the generic drugs is effective to reduce medical costs.
Conclusion: For further promoting the use of the generic drugs, we consider it essential to compare the therapeutic equivalence and the safety of the original and the generic drugs in clinical practice.
3.Efficacy and Safety of Pemafibrate and Bezafibrate in Patients with Type 2 Diabetes
Kaori BANDO ; Chinami SUZUKI ; Yuki YAMASHITA ; Akifumi MIZUTANI ; Akio SHIBANAMI ; Kazuya HIURA
Japanese Journal of Drug Informatics 2022;24(3):159-165
Objective: Management of low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) is important for patients with type 2 diabetes merger hyperlipidemia. Pemafibrate (PF) has different characteristics from conventional fibrates. In this study, we retrospectively compared the efficacy and safety of PF and bezafibrate (BF) in patients with type 2 diabetes merger hypertriglyceridemia.Methods: Patients who were administered PF (0.2 mg/day) or BF (400 mg/day) for 24 weeks or longer were included. Twenty patients in each group were extracted using propensity score matching (PS). PS was calculated using the patient background (before the start of administration) of PF or BF. We investigated lipid-related parameters (TG, high density lipoprotein cholesterol [HDL-C], and LDL-C) and other laboratory test parameters pre administration and 24 weeks post administration.Results: TG decreased significantly in both groups (p<0.05). However, there were no significant differences between the two groups in the TG treatment target (<150 mg/dL) achievement rate (p =1.00), TG change rate (p=0.84), and TG change amount (p=0.77). In addition, there were no significant changes in HDL-C and LDL-C in both groups. In the PF group, alanine transaminase (ALT) (p< 0.05), alkaline phosphatase (p<0.05) decreased. In the BF group, ALT (p<0.05) and γ-GTP (p<0.05) decreased. Both groups showed improvement in liver function after 24 weeks. eGFR (p<0.05) significantly decreased only BF group. There were no significant changes in renal function, creatine kinase (CK), or hemoglobin A1c (HbA1c) in either group.Conclusion: Our study suggests that there is no difference in the TG lowering effect and safety of PF and BF in type 2 diabetic patients.
4.Usefulness of Cystatin C-Based Renal Function Assessment in Patients Undergoing Paclitaxel and Carboplatin Combination Therapy
Ayaka WAKAMATSU ; Aya TANAKA ; Ryosuke WAKAMATSU ; Yuki YAMASHITA ; Akio SHIBANAMI ; Kazuya HIURA
Journal of the Japanese Association of Rural Medicine 2024;72(5):385-393
We investigated the relationship between renal function assessment based on cystatin C (CsyC) and serum creatinine levels and the status of chemotherapy use in patients with gynecological cancer undergoing paclitaxel and carboplatin therapy. A significant positive correlation was found between estimated glomerular filtration rate from creatinine (eGFRcre) and eGFR from CsyC (eGFRcys) in the 98 patients included in the study. When eGFRcre and eGFRcys values were grouped according to GFR categories in the CKD severity classification, severe cases (eGFRcys < eGFRcre) were of more advanced age (P < 0.05) and had lower albumin levels (P < 0.01) than matched cases. Although no clear relationship was found between renal function assessment and chemotherapy status, the CysC and eGFRcys values tended to be higher and lower, respectively, in patients whose chemotherapy was deferred (P < 0.01 for CysC, P = 0.07 for eGFRcys). These results suggest that eGFRcre-based renal function assessment is overestimated compared with eGFRcys-based assessment in patients with gynecological cancer and may lead to carboplatin overdose or treatment deferral in elderly patients and patients with hypoalbuminemia.
5.Multi-Institutional Joint Study on Adverse Events of Original and Generic Gemcitabine Drugs (Gemzar® vs. Gemcitabine Sandoz) Using Propensity Score Matching
Chinami SUZUKI ; Kazuya HIURA ; Mitsugu TANAYA ; Hiroshi SATO ; Yuji KOHARA ; Akio SHIBANAMI ; Hiroaki WATANABE
Japanese Journal of Drug Informatics 2020;22(1):24-29
Objective: The use of generic drugs is promoted to reduce medical costs and copayments. However, tumor agents are expensive and generic drugs are not widelyused. Thus, it is necessaryto evaluate the safetyof generic drugs in more detail. We compared the incidence of adverse events between the original drug (Gemzar®: GEM) and generic drug (Gemcitabine [Sandoz]: GE-GEM) using propensityscore (PS) matching.Methods: We investigated adverse events in patients who received one course of GEM or GE-GEM. The patient background (age,sex, BSA, cancer type, stage, metastasis, surgical history, and radiotherapy) and administration status (administration route and RDI) were used to calculate the PS.Results: Among all patients (GEM: 51, GE-GEM: 54), a significantlygreater number in the GE-GEM group had cancer metastasis. On comparison of adverse events, there were significantlymore cases of vascular pain (p<0.05) in the GEM group, and manycases of nausea (p=0.08) and rash (p=0.08). Fortypatients in each group were extracted byPS matching. There were no significant differences in the patient background between the groups, and on comparison of adverse events, the two groups did not significantly differ.Conclusion: Our studysuggested that there is no difference in side effects between Gemzar® and gemcitabine [Sandoz]. To compare the incidence of adverse events, it is useful to use PS matching in clinical practice.