Association between psychomotor function and ALDH2 genotype after consuming barley shochu: A randomized crossover trial.

Sustained exposure to acetaldehyde, the major metabolite of ethanol, may influence psychomotor performance even after the breath ethanol level significantly drops several hours following ethanol consumption. We examined the relationship between psychomotor function and changes in exhaled ethanol and acetaldehyde concentrations after consuming a low dose (0.33 g/kg) of barley shochu, a traditional Japanese distilled alcohol beverage, at the point when the exhaled ethanol concentrations dropped below 78,000 parts per billion (0.15 mg/L), the standard threshold for driving under the influence of alcohol in Japan. We assessed how the genetic polymorphisms of rs671 G/G homozygous (*1/*1) and G/A heterozygous (*1/*2) of ALDH2 influenced the kinetics of ethanol and acetaldehyde in exhaled air and psychomotor dynamics using the Digit Symbol Substitution Test (DSST), Critical Flicker Fusion Test (CFFT), and visual analogue scale (VAS) up to 12 h after shochu or water intake. There was no significant difference in DSST and CFFT scores depending on genotype; however, the time required for the DSST to attain the level prior to drinking was longer in the ALDH2 *1/*2 group than in the *1/*1 group. In the VAS test, facial flushing and mood elevation tended to be higher in the *1/*2 group after shochu consumption. VAS scores for mood elevation and facial flushing correlated with acetaldehyde concentration in exhaled breath. These results indicate that DSST recovery tends to be slower and mood elevation higher in the ALDH2 *1/*2 group even when exposed to a low dose of alcohol.

No Effect of Digoxin on Rosuvastatin Pharmacokinetics in Healthy Subjects: Utility of Oita Combination for Clinical Drug-Drug Interaction Study.

This study evaluated the utility of combination of digoxin (0.25 mg) and rosuvastatin (5 mg) as a new transporter (P-glycoprotein/breast cancer resistance protein/organic anion-transporting polypeptide (OATP)1B1/OATP1B3) probe cocktail (Oita combination) for drug-drug interaction (DDI) studies by demonstrating lack of DDI of digoxin on the pharmacokinetics (PKs) of rosuvastatin, as it was already known that rosuvastatin did not affect digoxin PK. This was an open-label, two-period study in which the primary end points were the geometric mean ratio (GMR) of the area under the plasma rosuvastatin concentration-time curve from time zero to last (AUClast ) after rosuvastatin administration combined with digoxin to that after rosuvastatin administration alone and its 90% confidence interval (CI). As the GMR of AUClast was 0.974 and its 90% CI was 0.911-1.042, it was judged that digoxin does not affect rosuvastatin PK. Results of this study have rationalized utility of the Oita combination as a transporter probe cocktail for clinical DDI studies.

Histological evaluation of nintedanib in non-alcoholic steatohepatitis mice.

AIMS: In addition to potentially progressing to either cirrhosis or hepatocellular carcinoma, non-alcoholic steatohepatitis (NASH) is currently the leading indication for liver transplantation. Nintedanib has been clinically used to treat idiopathic pulmonary fibrosis for many years, but its effects in an animal model of NASH have not been tested. The purpose of this study was to evaluate the effects of nintendanib on NASH in choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD)-fed mice. MAIN METHODS: Male C57BL/6 mice were fed a CDAHFD for 6 weeks to induce NASH with liver fibrosis, and they were administered nintedanib (60 mg/kg/day) or distilled water orally in the last 2 weeks of the feeding period. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglyceride, and non-esterified fatty acids concentrations were measured. Serum cytokeratin 18 fragment (CK18) was detected using ELISA. Liver tissue sections from mice were stained with hematoxylin-eosin and Masson's trichrome to assess the level of steatohepatitis and fibrosis. KEY FINDINGS: CDAHFD-fed mice exhibited higher serum ALT, AST, and ALP levels compared with Control mice. A significant increase in the serum CK18 level was observed in the NASH group compared with the Control group. CDAHFD feeding also enhanced steatohepatitis and hepatic fibrosis pathological features, which were reduced after nintedanib treatment. SIGNIFICANCE: Nintedanib exerted anti-inflammatory and anti-fibrotic effects in CDAHFD-induced NASH mice.

Utilisation of human pharmacology studies with biomarkers for new drug applications in Japan.

OBJECTIVE: This study evaluated the utilisation of human pharmacology studies with biomarkers for either efficacy or safety estimation conducted for new drug applications (NDAs) submitted to the Japanese regulatory authority, the Ministry of Health, Labour and Welfare (MHLW). METHODS: A total of 50 new chemical entities (NCEs) posted on the Websites, which were approved from June 2000 to November 2001, were evaluated by investigating their approval information. The utilisation of human pharmacology studies with biomarkers was evaluated by focusing on the classification referred to biomarkers for either efficacy or safety estimation and timing of studies. RESULTS: The human pharmacology studies with biomarkers for either efficacy or safety estimation were conducted in 20 compounds classified by utilising measures of either efficacy (17 compounds) or safety (seven compounds). In 4 of 17 NCEs, some of the biomarkers in human pharmacology studies were similar to the clinical endpoints for efficacy assessment in therapeutic exploratory and/or therapeutic confirmatory studies. For safety assessment in therapeutic exploratory and/or therapeutic confirmatory studies, clinical endpoints rather than biomarkers in human pharmacology studies were used in all seven NCEs. The timing of each type of clinical study could only be obtained for 15 NCEs. Of these 15 NCEs, human pharmacology studies with biomarkers for either efficacy or safety estimation were conducted on six compounds. There were only two compounds for which human pharmacology studies with biomarkers for efficacy estimation were conducted before pivotal studies such as a therapeutic exploratory study or a bridging study. CONCLUSION: Our survey suggests that with Japanese NDAs, human pharmacology studies with biomarkers for either efficacy or safety estimation do not play a key role in accelerating drug development and maximising the knowledge gained from confirmatory trials. The relationship between a biomarker and a clinical endpoint should be investigated appropriately for accelerating drug development. We think that the utilisation of human pharmacology studies with biomarkers for either efficacy or safety estimation in the regulatory review process for NDAs should be encouraged with the advancements of drug evaluation research using an appropriate biomarker based on clinical pharmacology.

The effect of erythromycin and clarithromycin on the pharmacokinetics of intravenous digoxin in healthy volunteers.

Several case reports have suggested an interaction between digoxin and macrolide antibiotics. The authors investigated the effect of erythromycin and clarithromycin on the pharmacokinetics of intravenously administered digoxin (0.5 mg) in healthy subjects. Nine male subjects participated in three studies (digoxin alone, digoxin with erythromycin, and digoxin with clarithromycin). Subjects took erythromycin (800 mg per day) or clarithromycin (400 mg per day) on the day before digoxin dosing and during the kinetic study, Neither of the macrolides affected serum digoxin concentration-time curves. However, more than 1.3-fold increases in urinary digoxin excretions were observed during erythromycin and clarithromycin coadministration compared with digoxin alone. There were significant differences in renal clearance between macrolide coadministration and the control condition (digoxin alone: 98.4 ml/min; digoxin with erythromycin: 137.3 ml/min; digoxin with clarithromycin: 133.6 ml/min). In conclusion, neither erythromycin nor clarithromycin has a significant effect on serum digoxin disposition after an intravenous administration. Renal digoxin excretion is not inhibited but rather enhanced by both macrolides.

Protein binding of valproic acid in Japanese pediatric and adult patients with epilepsy.

The binding of valproic acid to serum proteins in pediatric and adult patients was studied. Serum samples were obtained from 48 Japanese pediatric patients with epilepsy (group A) and 48 Japanese adult patients with epilepsy (group B) receiving valproic acid monotherapy. The patients' age ranged from 1 to 15 years for the pediatric patients and from 18 to 44 years (group B--younger) and 45 to 63 years (group B--older) for the adult patients. The serum concentrations of total and unbound valproic acid were measured by fluorescence polarization immunoassay, and the unbound serum fraction of valproic acid was analyzed by ultrafiltration. The mean association constant, K, and total concentration of binding sites, n(P), were as follows: group A, K = 0.016 L/mumol, n(P) = 1077 microM; group B, K = 0.011 L/mumol, n(P) = 1365 microM; group B--younger, K = 0.013 L/mumol, n(P) = 1291 microM; and group B--older, K = 0.006 L/mumol, n(P) = 1827 microM. Significant differences between groups A and B were observed in the serum free fatty acid concentration and the serum concentration ratio of free fatty acids to albumin. However, no significant differences between the two groups were observed in the binding of valproic acid to serum proteins. Group A's serum concentration ratio of free fatty acids to albumin was significantly lower than in group B--older and was lower than in group B--younger. However, there were no significant differences in binding between group A and groups B--younger and B--older. The serum concentration of albumin was significantly higher in group B--younger than in group B--older. Consequently, there was a significant difference in binding between groups B--younger and B--older. The serum protein binding of valproic acid was similar in pediatric and adult patients with epilepsy, but binding characteristics differed between younger and older adults.

Evaluation of Binding Equation Method for Unbound Serum Concentration Prediction of Valproic Acid in Polytherapy Pediatric Patients with Epilepsy.

In a previous study, we determined the in vivo population binding parameters of valproic acid (VPA) to serum proteins at single dose in nine healthy young and defined a binding equation that was derived from the Scatchard equation. Schever et al. and Yu also determined the in vivo population binding parameters of VPA in patients with epilepsy receiving VPA monotherapy or polytherapy. In this study, we retrospectively evaluated the ability of a binding equation using each of population mean binding parameters of Kodama et al. (Method 1), Scheyer et al. (Method 2), or Yu (Method 3) to predict the unbound serum VPA concentration in 23 pediatric patients with epilepsy receiving polytherapy. Mean prediction error, mean absolute prediction error (MAE), and root mean squared error (RMSE) were separately calculated for each method and served as a measure of prediction bias and precision. All three methods were significantly biased, showing a bias to overpredict unbound serum VPA. The MAEs and RMSEs for Methods 1 and 2 were similar in magnitude (Method 1: MAE = 16.5, RMSE = 23.1; Method 2: MAE = 14.0, RMSE = 17.5). On the other hand, each value for Method 3 was extremely high (MAE = 32.8 and RMSE = 36.3). Method 3 is apparently inferior to other two methods in accuracy and precision. For Methods 1 and 2, similar tendency to overprediction was observed in total concentration above 400 &mgr;mol L(minus sign1). These two methods may be useful to patients with total VPA lower than 400 &mgr;mol L(minus sign1).