TAS-303 effects on urethral sphincter function in women with stress urinary incontinence: phase I study.

INTRODUCTION AND HYPOTHESIS: TAS-303, which selectively inhibits noradrenaline reuptake, was developed for treating stress urinary incontinence (SUI). The proximal urethra mainly comprises smooth muscle fibers in which α1 adrenergic receptors are abundant. This study was conducted to evaluate the effect of TAS-303 on urethral function and its safety profile in female patients with SUI. METHODS: In total, 16 women (age, 20-64 years) with SUI and > 5.0 g of leakage in the 1-h pad test at screening were randomized and administered the assigned treatment in a double-blind manner. The primary end point was change in the maximal urethral closure pressure (MUCP) at 6 h post-dose. The secondary end point was change in the urethral closure pressure of the entire urethra and each urethral region (proximal, middle, and distal) at 6 h post-dose. The results were analyzed using a t-test. RESULTS: The mean change ± standard deviation in MUCP at 6 h post-dose was 3.473 ± 12.154 cmH2O for TAS-303 and 2.615 ± 9.794 cmH2O for placebo (between-group difference: 0.858 cmH2O, P = 0.8047). The mean changes ± standard deviation in urethral closure pressure of the proximal urethra at 6 h after the administration of TAS-303 18 mg and placebo were 3.863 ± 10.941 and 1.634 ± 12.093, respectively (between-group difference: 2.229 cmH2O, P = 0.5976). CONCLUSIONS: No significant difference in MUCP and urethral closure pressure was found between TAS-303 and placebo. However, the change in the proximal urethral closure pressure with TAS-303 was larger than that with placebo. This suggests that TAS-303 has pharmacological effects on urethral sphincteric function.

Effects of itraconazole and rifampicin on the single-dose pharmacokinetics of the nonsteroidal mineralocorticoid receptor blocker esaxerenone in healthy Japanese subjects.

AIMS: To investigate the effects of the strong cytochrome P450 (CYP) 3A inhibitor itraconazole and the strong CYP3A inducer rifampicin on the pharmacokinetics of single-dose esaxerenone, a nonsteroidal mineralocorticoid receptor blocker, in healthy Japanese subjects. METHODS: Two open-label, single-sequence, crossover studies were conducted in healthy Japanese males aged 20-45 years. In Study 1 (n = 20), subjects received a single oral 2.5 mg dose of esaxerenone (Days 1, 13), with itraconazole 200 mg twice daily (Day 8) and once daily (Days 9-16). In Study 2 (n = 12), subjects received a single oral 5 mg dose of esaxerenone (Days 1, 13), with rifampicin 600 mg once daily (Days 8-16). The plasma concentration of esaxerenone and esaxerenone metabolites were measured using liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated using noncompartmental analysis, and safety was assessed. RESULTS: Esaxerenone exposure increased when coadministered with itraconazole. Geometric least-square mean ratios (90% confidence interval) of peak plasma esaxerenone concentration (Cmax ), area under the plasma concentration-time curve (AUC) from zero until the last measurable concentration (AUClast ) and AUC from zero until infinity (AUCinf ) were 1.13 (1.05, 1.20) ng mL-1 , 1.47 (1.40, 1.54) ng h mL-1 and 1.53 (1.45, 1.62) ng h mL-1 , respectively. Esaxerenone exposure decreased when coadministered with rifampicin. Geometric least-squares mean ratios (90% confidence interval) of esaxerenone Cmax , AUClast and AUCinf were 0.659 (0.599, 0.724), 0.315 (0.300, 0.332) and 0.312 (0.297, 0.328), respectively. CONCLUSION: Itraconazole increased esaxerenone AUCinf by 53.1%, and rifampicin decreased esaxerenone AUCinf by 68.8%. These results suggest that caution is recommended when coadministering esaxerenone with strong inhibitors and inducers of CYP3A.

Elucidation of N 1-methyladenosine as a Potential Surrogate Biomarker for Drug Interaction Studies Involving Renal Organic Cation Transporters.

Endogenous substrates are emerging biomarkers for drug transporters, which serve as surrogate probes in drug-drug interaction (DDI) studies. In this study, the results of metabolome analysis using wild-type and Oct1/2 double knockout mice suggested that N 1-methyladenosine (m1A) was a novel organic cation transporter (OCT) 2 substrate. An in vitro transport study revealed that m1A is a substrate of mouse Oct1, Oct2, Mate1, human OCT1, OCT2, and multidrug and toxin exclusion protein (MATE) 2-K, but not human MATE1. Urinary excretion accounted for 77% of the systemic elimination of m1A in mice. The renal clearance (46.9 ± 4.9 ml/min per kilogram) of exogenously given m1A was decreased to near the glomerular filtration rates by Oct1/2 double knockout or Mate1 inhibition by pyrimethamine (16.6 ± 2.6 and 24.3 ± 0.6 ml/min per kilogram, respectively), accompanied by significantly higher plasma concentrations. In vivo inhibition of OCT2/MATE2-K by a single dose of 7-[(3R)-3-(1-aminocyclopropyl)pyrrolidin-1-yl]-1-[(1R,2S)-2-fluorocyclopropyl]-8-methoxy-4-oxoquinoline-3-carboxylic acid in cynomolgus monkeys resulted in the elevation of the area under the curve of m1A (1.72-fold) as well as metformin (2.18-fold). The plasma m1A concentration profile showed low diurnal and interindividual variation in healthy volunteers. The renal clearance of m1A in younger (21-45 year old) and older (65-79 year old) volunteers (244 ± 58 and 169 ± 22 ml/min per kilogram, respectively) was about 2-fold higher than the creatinine clearance. The renal clearances of m1A and creatinine were 31% and 17% smaller in older than in younger volunteers. Thus, m1A could be a surrogate probe for the evaluation of DDIs involving OCT2/MATE2-K. SIGNIFICANCE STATEMENT: Endogenous substrates can serve as surrogate probes for clinical drug-drug interaction studies involving drug transporters or enzymes. In this study, m1A was found to be a novel substrate of renal cationic drug transporters OCT2 and MATE2-K. N 1-methyladenosine was revealed to have some advantages compared to other OCT2/MATE substrates (creatinine and N 1-methylnicotinamide). The genetic or chemical impairment of OCT2 or MATE2-K caused a significant increase in the plasma m1A concentration in mice and cynomolgus monkeys due to the high contribution of tubular secretion to the net elimination of m1A. The plasma m1A concentration profile showed low diurnal and interindividual variation in healthy volunteers. Thus, m1A could be a better biomarker of variations in OCT2/MATE2-K activity caused by inhibitory drugs.

Effects of magnesium oxide on pharmacokinetics of L-dopa/carbidopa and assessment of pharmacodynamic changes by a model-based simulation.

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. To assess pharmacodynamic changes with the MgO treatment, we applied a model-based meta-analysis (MBMA). METHODS: The effects of MgO on the stabilities of L-dopa and carbidopa were evaluated in in vitro studies. We conducted pharmacokinetic interaction studies of MgO and LDCD on rats and healthy volunteers. A clinical study was conducted with an open-label, non-randomized, single-arm, and two-phase study. In MBMA, we constructed a population pharmacokinetic/pharmacodynamic model of L-dopa and predicted the effects of the MgO treatment on the pharmacodynamics of L-dopa. RESULTS: In vitro results suggested that carbidopa was unstable under alkaline pH conditions. Reductions in plasma LDCD concentrations were observed after oral-MgO/oral-LDCD, but not in oral-MgO/i.v.-LDCD treatments in rats, suggesting that the gastrointestinal tract is an interaction site. A healthy volunteer study showed that MgO was also associated with significant decreases of 35.3 and 80.9% in the AUC0-12 of L-dopa and carbidopa, respectively. A model-based simulation suggested that the MgO treatment was undesirable for the effectiveness of L-dopa. CONCLUSIONS: This is the first study to show a clear pharmacokinetic interaction between LDCD and MgO in humans. Further investigations to confirm the effects of MgO on the pharmacodynamics of L-dopa are required.

Safety, Tolerability, and Pharmacokinetics of NK-104-NP.

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. To accomplish this purpose, phase I clinical trials were conducted. In the single intravenous administration regimen, 40 healthy subjects were enrolled and PK (pharmacokinetic) parameters in 4 groups (1, 2, 4, and 8 mg as pitavastatin calcium) were as follows: 1.00 hour after the administration, the plasma concentration of pitavastatin reached Cmax (the maximum drug concentration) in all groups. Cmax, AUC0-t (area under the curve from time 0 to the last measurable concentration) and AUC0-∞ (area under the curve from time 0 extrapolated to infinite time) were increased in a dose-dependent manner. Population pharmacokinetic analysis based on these results indicated no accumulation of pitavastatin after repeated administration of NK-104-NP for 7 days. In this 7-day administration trial, the mean Cmax and AUC0-∞ of pitavastatin were not significantly different between days 1 and 7, suggesting that pitavastatin is unlikely to accumulate after repeated administration. In these trials, three adverse events (AEs) were reported, but they were resolved without any complications and judged to have no causal relationships with NK-104-NP. These results indicate that the innovative nanotechnology-based medicine NK-104-NP exhibited dose-dependent pharmacokinetics and was well tolerated with no significant AEs in healthy volunteers.

Effects of DPP-4 inhibitor linagliptin and GLP-1 receptor agonist liraglutide on physiological response to hypoglycaemia in Japanese subjects with type 2 diabetes: A randomized, open-label, 2-arm parallel comparative, exploratory trial.

Dipeptidyl peptidase-4 (DPP-4) inhibitors reduce the risk of hypoglycaemia, possibly through augmentation of glucose-dependent insulinotropic polypeptide (GIP) action, but not that of glucagon-like peptide-1 (GLP-1) on glucagon secretion. To examine this model in Japanese individuals with type 2 diabetes (T2D), the effects of the DPP-4 inhibitor linagliptin on glucagon and other counter-regulatory hormone responses to hypoglycaemia were evaluated and compared with those of the GLP-1 receptor agonist liraglutide in a multi-centre, randomized, open-label, 2-arm parallel comparative, exploratory trial. Three-step hypoglycaemic clamp glucose tests preceded by meal tolerance tests were performed before and after 2-week treatment with the drugs. Glucagon levels were increased during the hypoglycaemic clamp test at 2.5 mmol/L. This increase was similar in the linagliptin and liraglutide groups, both before and after the 2-week treatment. Changes in other counter-regulatory hormones (ie, growth hormone, cortisol, epinephrine and norepinephrine) were also similar between the groups, but were suppressed substantially after 2-week treatment compared to baseline. In conclusion, we confirmed that the glucagon response to hypoglycaemia was not affected by linagliptin or liraglutide treatment in Japanese individuals with T2D.

Clarification of the Mechanism of Clopidogrel-Mediated Drug-Drug Interaction in a Clinical Cassette Small-dose Study and Its Prediction Based on In Vitro Information.

Clopidogrel is reported to be associated with cerivastatin-induced rhabdomyolysis, and clopidogrel and its metabolites are capable of inhibiting CYP2C8 and OATP 1B1 in vitro. The objective of the present study was to identify the mechanism of clopidogrel-mediated drug-drug interactions (DDIs) on the pharmacokinetics of OATP1B1 and/or CYP2C8 substrates in vivo. A clinical cassette small-dose study using OATPs, CYP2C8, and OATP1B1/CYP2C8 probe drugs (pitavastatin, pioglitazone, and repaglinide, respectively) with or without the coadministration of either 600 mg rifampicin (an inhibitor for OATPs), 200 mg trimethoprim (an inhibitor for CYP2C8), or 300 mg clopidogrel was performed, and the area under the concentration-time curve (AUC) ratios (AUCRs) for probe substrates were predicted using a static model. Clopidogrel increased the AUC of pioglitazone (2.0-fold) and repaglinide (3.1-fold) but did not significantly change the AUC of pitavastatin (1.1-fold). In addition, the AUC of pioglitazone M4, a CYP2C8-mediated metabolite of pioglitazone, was reduced to 70% of the control by coadministration of clopidogrel. The predicted AUCRs using the mechanism-based inhibition of CYP2C8 by clopidogrel acyl-ß-glucuronide were similar to the observed AUCRs, and the predicted AUCR (1.1) of repaglinide using only the inhibition of OATP1B1 did not reach the observed AUCR (3.1). In conclusion, a single 300 mg of clopidogrel mainly inhibits CYP2C8-mediated metabolism by clopidogrel acyl-ß-glucuronide, but its effect on the pharmacokinetics of OATP1B1 substrates is negligible. Clopidogrel is expected to have an effect not only on CYP2C8 substrates, but also dual CYP2C8/OATP1B1 substrates as seen in the case of repaglinide.

Pharmacokinetics and pharmacodynamics of FSK0808 and Gran after single intravenous drip administration or single subcutaneous administration: comparative study in healthy Japanese adult male subjects.

FSK0808 is a recombinant human granulocyte colony-stimulating factor developed by Fuji Pharma Co., Ltd and Mochida Pharmaceutical Co., Ltd. as a biosimilar product of Gran®. We verified the pharmacokinetic/pharmacodynamic equivalence of FSK0808 and commercially available Gran® by a randomized crossover study of single intravenous dose (200 µg/m(2)) and single subcutaneous dose (400 µg/m(2)) in healthy Japanese adult male subjects. According to the bioequivalence guidelines, the area under the blood concentration - time curve by 48 hours after administration (AUC0-48) in a single intravenous drip (IVD) study, and AUC0-48 and maximum blood concentration (Cmax) in a single subcutaneous (SC) dose study were used as primary endpoints, and the pharmacodynamic parameters including absolute neutrophil count (ANC) or number of CD34 positive cells (CD34(+) cells) as secondary endpoints. The safety was evaluated based on the characteristics and incidence of adverse reactions. As a result, the 90% confidence interval (CI) of the difference in mean value for AUC0-48 among drugs ranged from log(0.8) to log(1.25), in the IVD study, and those for Cmax and AUC0-48 were within the range of log(0.8)-log(1.25) in the SC study. Those for secondary endpoints were all within the range of log(0.8)-log(1.25). Thus, the pharmacokinetics/pharmacodynamics of both drugs were considered equivalent for all routes of administration, and the profiles of adverse reactions were also very similar.

Korean, Japanese, and Chinese populations featured similar genes encoding drug-metabolizing enzymes and transporters: a DMET Plus microarray assessment.

BACKGROUND: Interethnic differences in genetic polymorphism in genes encoding drug-metabolizing enzymes and transporters are one of the major factors that cause ethnic differences in drug response. This study aimed to investigate genetic polymorphisms in genes involved in drug metabolism, transport, and excretion among Korean, Japanese, and Chinese populations, the three major East Asian ethnic groups. METHODS: The frequencies of 1936 variants representing 225 genes encoding drug-metabolizing enzymes and transporters were determined from 786 healthy participants (448 Korean, 208 Japanese, and 130 Chinese) using the Affymetrix Drug-Metabolizing Enzymes and Transporters Plus microarray. To compare allele or genotype frequencies in the high-dimensional data among the three East Asian ethnic groups, multiple testing, principal component analysis (PCA), and regularized multinomial logit model through least absolute shrinkage and selection operator were used. RESULTS: On microarray analysis, 1071 of 1936 variants (>50% of markers) were found to be monomorphic. In a large number of genetic variants, the fixation index and Pearson's correlation coefficient of minor allele frequencies were less than 0.034 and greater than 0.95, respectively, among the three ethnic groups. PCA identified 47 genetic variants with multiple testing, but was unable to discriminate ethnic groups by the first three components. Multinomial least absolute shrinkage and selection operator analysis identified 269 genetic variants that showed different frequencies among the three ethnic groups. However, none of those variants distinguished between the three ethnic groups during subsequent PCA. CONCLUSION: Korean, Japanese, and Chinese populations are not pharmacogenetically distant from one another, at least with regard to drug disposition, metabolism, and elimination.

Measurement of drug concentration in the stomach after intragastric administration of drug solution to healthy volunteers: analysis of intragastric fluid dynamics and drug absorption.

PURPOSE: To evaluate the time-profile of intragastric fluid volume in humans after intragastric administration of drug solution. METHODS: Eight healthy volunteers were intragastrically administered 150 mL of drug solution containing atenolol (non-absorbable marker) and salicylic acid, then, aliquots of gastric fluid (ca. 2 mL) were sampled for 2 h through the catheter. Rate constants for secretion and emptying of the fluid were obtained by fitting the time-course of atenolol concentration to the simple gastric fluid transit model. Absorption of salicylic acid from the stomach was estimated by comparing its gastric concentration with that of atenolol. RESULTS: Kinetic analysis of atenolol concentration in the stomach indicated a rapid emptying of the fluid with an average half-life of 4.2 min. Steady-state intragastric fluid volume in 8 volunteers was estimated as 4-133 mL with an average of 42 mL. Intragastric concentration (normalized by dose) of salicylic acid was always lower than that of atenolol, showing approximately 40% of salicylic acid was absorbed from the stomach before emptying to the intestine. CONCLUSIONS: This study provided valuable information on intragastric fluid dynamics and gastric drug absorption in humans to establish a better in vitro-in vivo correlation in oral drug absorption.

Effectiveness of Live Attenuated Varicella-Zoster Vaccine in Adults Older than 50 Years in Japan: A Retrospective Cohort Study.

Background: In Japan, freeze-dried live attenuated varicella-zoster vaccine BIKEN is available for adults aged ≥50 years to prevent herpes zoster (HZ). A prospective cohort study of 1200 healthy adults and 300 patients with underlying illness confirmed vaccine safety between 2016 and 2017. However, evidence of vaccine effectiveness (VE) is limited. Methods: VE against HZ and postherpetic neuralgia (PHN) was evaluated in the vaccinated cohort of the previous safety study in a follow-up study between 2021 and 2022 and compared with unvaccinated family members. Self-administered questionnaires determined retrospective experiences of HZ and PHN diagnosis. Logistic regression estimated the VE by calculating the outcome odds ratio (OR) in vaccinated vs. unvaccinated groups: VE = (1 - OR) × 100(%). Results: Overall, 1098 vaccinated and 518 unvaccinated subjects were analysed. Between 2016 and 2022, 26 vaccinated (2.4%) and 22 unvaccinated (4.2%) subjects reported HZ diagnosis, and 3 vaccinated (0.3%) and 2 unvaccinated (0.4%) subjects reported PHN. Adjusted VE against a clinical diagnosis was 41% for HZ [-6% to 67%], with marginal significance, and 16% [-408% to 86%] for PHN. Stratification by age, sex, or comorbidities had an adjusted VE against HZ of ~40%, which was similar between strata. Conclusion: Freeze-dried live attenuated varicella-zoster vaccine reduces the risk of HZ regardless of age, sex, or comorbidities.

Comparison of self-reported symptoms in COVID-19 patients who had or had not previously received COVID-19 mRNA vaccination.

Although mRNA coronavirus disease 2019 (COVID-19) vaccines have been reported for high effectiveness against symptoms, it remains unclear whether post-vaccination infections are less symptomatic than infections in vaccine-naive individuals. We included patients with COVID-19 diagnosed by polymerase chain reaction tests during Japan's alpha and delta variant epidemics. COVID-19 symptoms at approximately 4 weeks were compared based on COVID-19 vaccination status. In total, 398 cases (372 symptomatic and 26 asymptomatic; 286 unvaccinated, 66 vaccinated with one dose, and 46 with two doses) were analyzed. The most common symptoms were fever (78.4%), fatigue (78.4%), cough (74.4%), loss of taste or smell (62.8%), and headache (59.8%). Post-vaccination infections were significantly less likely to be symptomatic. Possible confounder-adjusted odds ratios of two vaccine doses against fatigue, dry eyes and mouth, insomnia, fever, shortness of breath, unusual muscle pains, and loss of taste or smell were 0.18 (95% confidence interval [CI]: 0.09-0.38), 0.22 (95% CI: 0.08-0.59), 0.33 (95% CI: 0.14-0.80), 0.31 (95% CI: 0.15-0.63), 0.36 (95% CI: 0.16-0.76), 0.40 (95% CI: 0.19-0.82), and 0.44 (95% CI: 0.22-0.87), respectively. Post-vaccination infections after two mRNA COVID-19 vaccine doses show milder and fewer symptoms than infections in unvaccinated patients, highlighting the effectiveness of vaccination.

Effects of meal timing relative to dosing on the pharmacokinetics and pharmacodynamics of vildagliptin in Japanese patients with Type 2 diabetes.

OBJECTIVE: To assess the effects of meal timing on the pharmacokinetics and pharmacodynamics of the dipeptidyl peptidase IV (DPP-4) inhibitor vildagliptin in Japanese patients with Type 2 diabetes. METHODS: In this open-label, single-center crossover study, 12 Japanese patients with Type 2 diabetes were randomized to twice-daily vildagliptin 50 mg, administered 30 min before or immediately before breakfast and dinner for 7 days. After a 7-day washout period, patients received the other regimen. Blood samples were collected for the determination of vildagliptin, DPP-4, glucagon-like peptide-1 (GLP-1) and glucose. RESULTS: Vildagliptin absorption appeared slower when administered 30 min before rather than immediately before meals (tmax absolute range: 1.00 - 2.00 h vs. 0.33 - 1.58 h). Vildagliptin Cmax and AUC0-8 h were essentially the same irrespective of meal timing (geometric mean ratio: Cmax 1.08 (90% CI; 0.92 - 1.26); AUC0-8 h 0.97 (90% CI; 0.91 - 1.05)). Meal timing did not affect pharmacodynamics; complete DPP-4 inhibition (> 90%) was sustained for 8 h post-dose, and plasma active glucagon-like peptide-1 levels increased 2 - 3-fold from baseline. Fasting plasma glucose (FPG) and postprandial plasma glucose (PPPG) reductions from baseline did not differ significantly with meal timing (30 min before vs. immediately before: FPG, -8.9 vs. -5.8 mg/dl; adjusted AUE0-4 h, -67.0 vs. -51.0 mg×h/dl). Vildagliptin was well tolerated. CONCLUSIONS: Dosing 30 min or immediately before meals did not affect vildagliptin pharmacokinetics or pharmacodynamics in Japanese patients with Type 2 diabetes.

Pharmacogenomic/pharmacokinetic assessment of a four-probe cocktail for CYPs and OATPs following oral microdosing.

OBJECTIVES: To test whether the multiple phenotype and genotype relationships established using therapeutic dose, can be reproduced following oral microdosing using substrates of CYP2C9 (warfarin and glibenclamide), CYP2C19 (lansoprazole), CYP2D6 (dextromethorphan), and OATPs (glibenclamide). METHODS: A cocktail of test drugs was administered orally under the microdose in liquid or capsule form, and then a therapeutic dose of dextromethorphan was administered to 17 healthy subjects whose genotypes for CYPs and OATPs had been prescreened. Concentrations of the drugs and their metabolites were measured by LC-MS/MS. RESULTS: The AUC and t1/2 of glibenclamide following the microdosing tended to be higher and longer, respectively, in CYP2C9*1/*3 than CYP2C9*1/*1 subjects. In contrast, there were no significant differences in any of the pharmacokinetic parameters for warfarin between the two genotypes. For CYP2D6 following the therapeutic dose, there was good concordance between genotype and phenotype; however, such relationships disappeared after microdosing. For CYP2C19 following the microdosing, there were significant differences between EMs and PMs in the pharmacokinetic parameters of lansoprazole. The relative AUC0-12 ratio of lansoprazole in EMs and PMs was 1:3.3 - 4.3. Among test drugs, phenotypic measurements of lansoprazole accorded well with the CYP2C19 genotype at the microdose as well as therapeutic dose. CONCLUSIONS: The present study suggests that 1) the sampling strategy should be optimized according to pharmacokinetic profiles of the test drugs following oral microdosing, and 2) microdosing can be applied to the pharmacogenomic study of CYP-specific drugs.

Real-World Effectiveness of the mRNA COVID-19 Vaccines in Japan: A Case-Control Study.

The real-world effectiveness of the coronavirus disease 2019 (COVID-19) vaccines in Japan remains unclear. This case-control study evaluated the vaccine effectiveness (VE) of two doses of mRNA vaccine, BNT162b2 or mRNA-1273, against the delta (B.1.617.2) variant in the Japanese general population in the period June-September 2021. Individuals in close contact with COVID-19 patients were tested using polymerase chain reaction (PCR). A self-administered questionnaire evaluated vaccination status, demographic data, underlying medical conditions, lifestyle, personal protective health behaviors, and living environment. Two vaccine doses were reported by 11.6% of cases (n = 389) and 35.2% of controls (n = 179). Compared with controls, cases were younger and had a lower proportion who always performed handwashing for ≥20 s, a higher proportion of alcohol consumers, and a lower proportion of individuals living in single-family homes or with commuting family members. After adjusting for these confounding factors and day of PCR testing by multivariate logistic regression analysis, the VE in the period June-July (delta variant proportion 45%) was 92% and 79% in the period August-September (delta variant proportion 89%). The adjusted VE for homestay, hotel-based isolation and quarantine, and hospitalization was 78%, 77%, and 97%, respectively. Despite declining slightly, VE against hospitalization remained robust for ~3 months after the second dose. Vaccination policymaking will require longer-term monitoring of VE against new variants.

Pharmacokinetic and pharmacogenomic profiles of telmisartan after the oral microdose and therapeutic dose.

OBJECTIVES: In this study, we evaluated (a) the contribution of SLCO1B3 and UGT1A polymorphisms to the pharmacokinetics of telmisartan in two forms, a microdose (MD) and a therapeutic dose (TD); (b) linkage disequilibrium (LD) between UGT1A1 and UGT1A3; and (c) linearity in the pharmacokinetics of telmisartan between the two forms. METHODS: Telmisartan was orally administered at MD condition (100 µg), and then at TD condition (80 mg) to 33 healthy volunteers whose genotypes were prescreened by DMET Plus. Plasma concentrations of telmisartan and its glucuronide were measured by LC-MS/MS, and population pharmacokinetic analysis was performed. RESULTS: No obvious effect of SLCO1B3 polymorphisms (334T>G, 699G>A, and rs11045585) on the pharmacokinetics of telmisartan was observed. The strong LD between UGT1A1*6 and UGT1A3*4a, and between UGT1A1*28 and UGT1A3*2a were observed. After both MD and TD administration, the mean area under the curve0-24 (±standard deviation) of telmisartan was significantly lower and higher in individuals with the UGT1A3*2a (TD, 1701±970 ng hr/ml; MD, 978±537 pg hr/ml) and *4a variants (TD, 5340±1168; MD, 3145±1093), respectively, compared with those in individuals with UGT1A3*1/*1 (TD, 2969±1456; MD, 1669±726). These results were quantitatively confirmed by population pharmacokinetic analysis. Nonlinearity of the dose-exposure relationship was observed between the MD and TD. CONCLUSION: The haplotypes of UGT1A3 significantly influenced pharmacokinetics of telmisartan and a strong LD between UGT1A1 genotype and UGT1A3 haplotype was observed. These findings are potentially of pharmacological and toxicological importance to the development and clinical use of drugs.

Pharmacokinetics of intravenous amiodarone and its electrocardiographic effects on healthy Japanese subjects.

The aim of this phase I, dose-escalating study was to evaluate the pharmacokinetics, electrocardiographic effect and safety of amiodarone after a single intravenous administration in Japanese subjects. Thirty-two healthy Japanese male volunteers (20-32 years) were randomized to three single-dose groups (1.25, 2.5 and 5.0 mg/kg). In each group, six (1.25 mg/kg) or ten (2.5 and 5.0 mg/kg) subjects received a single 15-min infusion of intravenous amiodarone, and two subjects received glucose solution as control. The pharmacokinetic profile, blood pressure and electrocardiographic analyses were obtained on a timely basis after up to 77 days. The maximum plasma concentration (C (max)) and area under the concentration-time curve (AUC(0-96)) for amiodarone 1.25, 2.5 and 5.0 mg/kg displayed dose-dependent characteristics: mean C (max) was 2,920 ± 610, 7,140 ± 1,480 and 13,660 ± 3,410 ng/ml, respectively; the mean AUC(0-96) was 3,600 ± 700, 8,100 ± 1,600 and 16,600 ± 4,300 ng h/ml, respectively. A long serum half-life (>14 days) was observed for amiodarone and desethylamiodarone. PR intervals were prolonged at 15 min (0.16 ± 0.0.1 vs. 0.15 ± 0.01 s, p = 0.03) and 18 min (0.17 ± 0.01 vs. 0.15 ± 0.01 s, p = 0.03) with the 5.0 mg/kg dose compared with baseline. No other significant changes in electrocardiographic parameters, pulse rate or blood pressure were observed. A needle-pain-induced vasovagal effect appeared in a volunteer, and three volunteers experienced pain at the drug infusion site. After a single infusion of amiodarone at doses of 1.25-5.0 mg/kg, serum concentrations increased in a dose-dependent manner. A single intravenous amiodarone dose barely affected the electrocardiographic parameters and was well tolerated.

Variability of post-void residual urine volume and bladder voiding efficiency in patients with underactive bladder.

OBJECTIVES: Post-void residual urine volume (PVR) and bladder voiding efficiency (BVE) are widely used as clinical parameters to evaluate patients with voiding dysfunction. The present study was conducted to assess the variability of PVR and BVE determinations in patients with underactive bladder (UAB). In addition, we focused on the bladder volume prior to voiding (BVvoid ) that may influence PVR and BVE, and investigated a correlation between PVR and BVvoid , and between BVE and BVvoid . METHODS: Ten patients with a symptom complex of UAB, who had PVR of 50 mL or greater, were admitted to hospital during a 24-hour period for the measurement of voided volume (VV) and PVR. PVR was measured by transabdominal ultrasonography. BVE was expressed by a fraction (%) of bladder volume evacuated ([VV/BVvoid ] × 100). RESULTS: Ten patients, five men (mean age of 65.0 years) and five women (mean age of 70.2 years), participated in this study. Regardless of gender, there was a large variation in repeated measurements of PVR in an individual patient. PVR increased with an increase in BVvoid , and there was a significant linear relationship between PVR and BVvoid . BVE was approximately constant after every voiding in each patient, and there was no significant linear relationship between BVE and BVvoid . CONCLUSIONS: Measurement of PVR was unreliable because of wide variation in the same individual. The variation of BVE was much smaller than PVR. BVE would be a reliable parameter with good reproducibility for the assessment of emptying function.

Statistical Analysis of the Axillary Temperatures Measured by a Predictive Electronic Thermometer in Healthy Japanese Adults.

Body temperature is important for diagnosing illnesses. However, its assessment is often a difficult task, considering the large individual differences. Although 37 °C has been the gold standard of body temperature for over a century, the temperature of modern people is reportedly decreasing year by year. However, a mean axillary temperature of 36.89 ± 0.34 °C reported in 1957 is still cited in Japan. To assess the measured axillary temperature appropriately, understanding its distribution in modern people is important. This study retrospectively analyzed 2454 axillary temperature measurement data of healthy Japanese adults in 2019 (age range, 20-79 years; 2258 males). Their mean temperature was 36.47 ± 0.28 °C (36.48 ± 0.27 °C in males and 36.35 ± 0.31 °C in females). Approximately 5% of the 20-39-year-old males had body temperature ≥37 °C, whereas 8% had a temperature ≥ 37 °C in the afternoon. However, none of the subjects aged ≥50 years reported body temperature ≥37 °C. In multivariable regression analysis, age, blood pressure, pulse rate, and measurement time of the day were associated with axillary temperature. Our data showed that the body temperature of modern Japanese adults was lower than that reported previously. When assessing body temperature, the age, blood pressure, pulse rate, and measurement time of the day should be considered.

Cerebrospinal Fluid Protein Concentration in Healthy Older Japanese Volunteers.

The concentration of cerebrospinal fluid total protein (CSF-TP) is important for the diagnosis of neurological emergencies. Recently, some Western studies have shown that the current upper reference limit of CSF-TP is quite low for older patients. However, little is reported about the concentration of CSF-TP in the older Asian population. In this study, we retrospectively analyzed the CSF-TP concentrations in healthy older Japanese volunteers. CSF samples in 69 healthy Japanese volunteers (age range: 55-73 years) were collected by lumbar puncture, and the data of CSF were retrospectively analyzed. The mean (standard deviation) CSF-TP was 41.7 (12.3) mg/dL. The older group (≥65 years old) had higher CSF-TP concentration than the younger group (55-64 years old). The 2.5th percentile and 97.5th percentile of CSF-TP were estimated as 22.5 and 73.2 mg/dL, respectively, which were higher than the current reference range in Japan (10-40 mg/dL). Conclusions: The reference interval of CSF-TP in the older population should be reconsidered for the precise diagnosis of neurological emergencies.