Publications by authors named "Yushi Kashihara"

Background: Theophylline, a xanthine derivative drug, is used for the treatment of respiratory diseases, such as asthma, and is primarily eliminated by hepatic metabolism. There is marked interindividual variability in theophylline clearance. Therefore, the aim of this study was to evaluate the influence of chronic hepatitis (CH), liver cirrhosis (LC), and other covariates on theophylline clearance by population pharmacokinetic (PPK) analysis.

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Background: Fosphenytoin, the diphosphate ester salt of phenytoin, is widely used to treat status epilepticus. The aim of this study was to develop a population pharmacokinetic (PPK) model to describe serum phenytoin concentrations after the intravenous administration of fosphenytoin in adult and elderly epileptic patients.

Methods: Patient backgrounds, laboratory tests, and prescribed drugs were retrospectively collected from electronic medical records.

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Article Synopsis
  • * Volunteers with the *15/*15 genotype showed significantly higher plasma concentrations of atorvastatin, pitavastatin, and rosuvastatin, suggesting that this genotype influences drug absorption more than the other genotypes.
  • * The findings indicate that coproporphyrin I, GLCA-S, and GCDCA-S may serve as useful indicators for evaluating OATP1B1 activity in humans, reinforcing ideas from previous studies.
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Aims: The aim of the present study was to quantitate the hypoglycaemic effects of dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1r) and sodium glucose cotransporter 2 inhibitors (SGLT2i) as add-on treatments to metformin monotherapy in patients with type 2 diabetes mellitus (T2DM) using a model-based meta-analysis (MBMA).

Methods: A systematic literature search of public databases was conducted to develop models that describe the time courses of the fasting plasma glucose (FPG)- and haemoglobin A1c (HbA1c)-lowering effects of three antidiabetic classes using NONMEM 7.3.

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Background: Magnesium oxide (MgO) is often co-prescribed with L-dopa/carbidopa (LDCD) to improve constipation in Parkinson's disease patients. The mixing of L-dopa and MgO has been shown to degrade L-dopa; however, there is no interaction study on humans. We proposed mechanisms for the interaction between LDCD and MgO and conducted pharmacokinetic studies on rats and humans.

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The objective of the present study was to develop a population pharmacodynamic (PPD) model to describe the glycated hemoglobin (HbA1c)-lowering effects of metformin in type 2 diabetes mellitus patients with and without secondary failure and to characterize changes in HbA1c levels in the two subpopulations using a mixture model. Information on patients was collected retrospectively from electronic medical records. In this study, the mixture model was used to characterize the bimodal effects of metformin.

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Pulmonary hypertension (PH) is a disease with poor prognosis, caused by the obstruction/stenosis of small pulmonary arteries. Statin is known to have vasodilating and anti-inflammatory property and is considered to be a candidate of therapeutic agents for the treatment of PH, but its efficacy has not been verified in clinical trials. We have formulated pitavastatin incorporating nanoparticles composed of poly (lactic-co-glycolic acid) (NK-104-NP) to improve drug delivery to the pulmonary arteries and evaluated their safety and pharmacokinetics in healthy volunteers.

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Article Synopsis
  • The study aimed to explore how atorvastatin and grapefruit juice affect the pharmacokinetics of certain drugs that are processed by OATP2B1 and BCRP in healthy volunteers.
  • Results indicated that grapefruit juice significantly decreased the absorption of the test drugs compared to a control phase, suggesting all five drugs are processed by OATP2B1, while atorvastatin did not have a similar effect.
  • Genetic factors, specifically the ABCG2 c.421C>A polymorphism, influenced the levels of sulfasalazine and rosuvastatin absorbed, while the SLCO2B1*3 genotype did not affect the pharmacokinetics of any of the tested drugs.
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