Comparison of effects of UGT1A1*6 and UGT1A1*28 on irinotecan-induced adverse reactions in the Japanese population: analysis of the Biobank Japan Project.

It has been reported that there are differences in effects on irinotecan-induced adverse reactions between UGT1A1*6 and UGT1A1*28. In order to compare those differences in the Japanese population, we examined the associations between UGT1A1 and irinotecan-induced adverse reactions using the BioBank Japan Project database. We genotyped UTG1A1*6 and UGT1A1*28 and conducted case-control analyses. A total of 651 patients (102 cases and 549 tolerant controls) were included in this study. The results showed that UGT1A1*6/*6 is a predictor of adverse drug reactions (ADRs) (p-value 0.00070, odds ratio 6.59, 95% confidence interval 2.33-18.6), whereas UGT1A1*6/*28 and UGT1A1*28/*28 were not. The subanalysis comprising only patients with UGT1A1*6/*6, UGT1A1*6/*28, and UGT1A1*28/*28 revealed a trend towards an increased risk of ADRs in patients with UGT1A1*6 (p-value 0.0092, odds ratio 4.39, 95% confidence interval 1.57-14.9). Multiple logistic regression analyses showed that use of platinum-based antineoplastic drugs and presence of UGT1A1*6/*6 were independent variables, significantly associated with ADRs. The diagnostic performance of a predictive model had a sensitivity of 49.0%, specificity of 70.1%, and a number needed to screen of 5.8. We concluded that UGT1A1 testing could be useful to predict irinotecan-induced ADRs, and that UTG1A1*6 rather than UGT1A1*28 contributed to ADR occurrence.

Phase I study of salazosulfapyridine in combination with cisplatin and pemetrexed for advanced non-small-cell lung cancer.

Spliced variant isoforms of CD44 (CD44v) are a marker of cancer stem cells in solid tumors. They stabilize the xCT subunit of the transporter system xc(-) and thereby promote synthesis of the antioxidant glutathione. Salazosulfapyridine (SASP) is an inhibitor of xCT and suppresses the proliferation of CD44v-positive cancer cells. Chemotherapy-naïve patients with advanced non-squamous non-small-cell lung cancer were enrolled in a dose-escalation study (standard 3 + 3 design) of SASP in combination with cisplatin and pemetrexed. The primary end-point was the percentage of patients who experience dose-limiting toxicity. Fifteen patients were enrolled in the study. Dose-limiting toxicity was observed in one of six patients at a SASP dose of 1.5 g/day (elevation of aspartate and alanine aminotransferase levels, each of grade 3), two of five patients at 3 g/day (hypotension or pneumonitis, each of grade 3), and two of three patients at 4.5 g/day (anorexia of grade 3). The maximum tolerated dose was thus 3 g/day, and the recommended dose was 1.5 g/day. The overall response rate was 26.7% and median progression-free survival was 11.7 months, much longer than that for cisplatin-pemetrexed alone in previous studies. Exposure to SASP varied markedly among individuals according to ABCG2 and NAT2 genotypes. The serum concentration of free CD44v protein was increased after the first cycle of treatment, possibly reflecting death of cancer stem cells. Salazosulfapyridine was thus given safely in combination with cisplatin-pemetrexed, with the addition of SASP tending to prolong progression-free survival. This trial is registered in the UMIN Clinical Trials Registry as UMIN000017854.

Dose-escalation study for the targeting of CD44v+ cancer stem cells by sulfasalazine in patients with advanced gastric cancer (EPOC1205).

BACKGROUND: Cancer stem cells (CSCs) have enhanced mechanisms of protection from oxidative stress. A variant form of CD44 (CD44v), a major CSC marker, was shown to interact with xCT, a subunit of cystine-glutamate transporter, which maintains high levels of intracellular reduced glutathione (GSH) which defend the cell against oxidative stress. Sulfasalazine (SSZ) is an inhibitor of xCT and was shown to suppress the survival of CD44v-positive stem-like cancer cells both in vitro and in vivo. To find the dose of SSZ which can safely reduce the population of CD44v-positive cells in tumors, a dose-escalation study in patients with advanced gastric cancer was conducted. METHODS: SSZ was given four times daily by oral administration with 2 weeks as one cycle. Tumor biopsies were obtained before and after 14 days of administration of SSZ to evaluate expression of CD44v and the intratumoral level of GSH. RESULTS: Eleven patients were enrolled and received a dosage from 8 to 12 g/day. Safety was confirmed up to a dosage of 12 g/day, which was considered the maximum tolerated dose. Among the eight patients with CD44v-positive cells in their pretreatment biopsy samples, the CD44v-positive cancer cell population appeared to be reduced in the posttreatment biopsy tissues of four patients. Intratumoral GSH levels were also decreased in two patients, suggesting biological effectiveness of SSZ at 8 g/day or greater. CONCLUSIONS: This is the first study of SSZ as an xCT inhibitor for targeting CSCs. Reduction of the levels of CD44v-positive cells and GSH was observed in some patients, consistent with the mode of action of SSZ in CSCs.

IKZF1, a new susceptibility gene for cold medicine-related Stevens-Johnson syndrome/toxic epidermal necrolysis with severe mucosal involvement.

BACKGROUND: Stevens-Johnson syndrome (SJS) and its severe form, toxic epidermal necrolysis (TEN), are acute inflammatory vesiculobullous reactions of the skin and mucous membranes, including the ocular surface, oral cavity, and genitals. These reactions are very rare but are often associated with inciting drugs, infectious agents, or both. OBJECTIVE: We sought to identify susceptibility loci for cold medicine-related SJS/TEN (CM-SJS/TEN) with severe mucosal involvement (SMI). METHODS: A genome-wide association study was performed in 808 Japanese subjects (117 patients with CM-SJS/TEN with SMI and 691 healthy control subjects), and subsequent replication studies were performed in 204 other Japanese subjects (16 cases and 188 control subjects), 117 Korean subjects (27 cases and 90 control subjects), 76 Indian subjects (20 cases and 56 control subjects), and 174 Brazilian subjects (39 cases and 135 control subjects). RESULTS: In addition to the most significant susceptibility region, HLA-A, we identified IKZF1, which encodes Ikaros, as a novel susceptibility gene (meta-analysis, rs4917014 [G vs. T]; odds ratio, 0.5; P = 8.5 × 10(-11)). Furthermore, quantitative ratios of the IKZF1 alternative splicing isoforms Ik1 and Ik2 were significantly associated with rs4917014 genotypes. CONCLUSION: We identified IKZF1 as a susceptibility gene for CM-SJS/TEN with SMI not only in Japanese subjects but also in Korean and Indian subjects and showed that the Ik2/Ik1 ratio might be influenced by IKZF1 single nucleotide polymorphisms, which were significantly associated with susceptibility to CM-SJS/TEN with SMI.

Genome-wide association study identifies HLA-A*3101 allele as a genetic risk factor for carbamazepine-induced cutaneous adverse drug reactions in Japanese population.

An anticonvulsant, carbamazepine (CBZ), is known to show incidences of cutaneous adverse drug reactions (cADRs) including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and drug-induced hypersensitivity syndrome (DIHS). To identify a gene(s) susceptible to CBZ-induced cADRs, we conducted a genome-wide association study (GWAS) in 53 subjects with the CBZ-induced cADRs, including SJS, TEN and DIHS, and 882 subjects of a general population in Japan. Among the single nucleotide polymorphisms (SNPs) analyzed in the GWAS, 12 SNPs showed significant association with CBZ-induced cADRs, and rs1633021 showed the smallest P-value for association with CBZ-induced cADRs (P = 1.18 × 10⁻¹³). These SNPs were located within a 430 kb linkage disequilibrium block on chromosome 6p21.33, including the HLA-A locus. Thus, we genotyped the individual HLA-A alleles in 61 cases and 376 patients who showed no cADRs by administration of CBZ (CBZ-tolerant controls) and found that HLA-A*3101 was present in 60.7% (37/61) of the patients with CBZ-induced cADRs, but in only 12.5% (47/376) of the CBZ-tolerant controls (odds ratio = 10.8, 95% confidence interval 5.9-19.6, P = 3.64 × 10⁻¹5), implying that this allele has the 60.7% sensitivity and 87.5% specificity when we apply HLA-A*3101 as a risk predictor for CBZ-induced cADRs. Although DIHS is clinically distinguished from SJS and TEN, our data presented here have indicated that they share a common genetic factor as well as a common pathophysiological mechanism. Our findings should provide useful information for making a decision of individualized medication of anticonvulsants.

Association of Genetic Variants of HLA-DQA1 with Bullous Pemphigoid Induced by Dipeptidyl Peptidase-4 Inhibitors.

Bullous pemphigoid (BP) is the most common autoimmune blistering disorder. Several factors, including an antidiabetic (dipeptidyl peptidase-4 inhibitor [DPP-4i]), have been reported to trigger BP. To identify the genetic variants associated with BP, GWAS and HLA fine-mapping analyses were conducted. The 21 cases of noninflammatory BP induced by DPP-4i (i.e., DPP-4i-induced noninflammatory BP) and 737 controls (first cohort) and the 8 cases and 164 controls (second cohort) were included in the GWAS. Combining GWAS satisfied the genome-wide significant association of HLA-DQA1 (chromosome 6, rs3129763 [T/C]) with the risk of DPP-4i-induced noninflammatory BP (allele T carrier of 72.4% [21 of 29] in cases vs. 15.3% [138 of 901] in controls; dominant model, OR = 14, P = 1.8 × 10-9). HLA fine mapping revealed that HLA-DQA1∗05 with serine at position 75 of HLA-DQα1 (Ser75) had the most significant association with the combined cohort of DPP-4i-induced noninflammatory BP (79.3% [23 of 29] cases vs. 16.1% [145 of 901] controls; dominant model, OR = 21, P = 2.0 × 10-10). HLA-DQα1 Ser75 polymorphism was located inside the functional pocket of HLA-DQ molecules, suggesting the impact of HLA-DQα1 Ser75 on DPP-4i-induced noninflammatory BP.

Characteristics of adverse drug reactions associated with antiepileptics at a tertiary children's hospital in Japan: A retrospective observational cohort study.

OBJECTIVE: The aim of this study was to explore the prescription pattern of antiepileptics and the relationship between antiepileptics and adverse drug reactions (ADRs) in a Japanese population. METHODS: A retrospective observational cohort study was conducted by reviewing the medical records of patients who visited or were admitted to a single tertiary care center between January 2011 and June 2019, were treated with antiepileptics, and developed allergic ADRs associated with these drugs. RESULTS: In total, 14,230 unique patients received antiepileptics during the study period. Diazepam was the most frequently used antiepileptic drug (74.8 %), followed by phenobarbital (14.3 %), valproic acid (11.4 %), fosphenytoin (10.0 %), and carbamazepine (7.3 %). Although a trend of increasing prevalence of newer generation antiepileptics was noted, most patients are still treated with older generation antiepileptics. Thirty-two (0.22 %) unique patients experienced ADRs associated with antiepileptics, and the antiepileptic drug most frequently associated with ADRs was carbamazepine, at a rate of 1.4 %. Three patients developed Stevens-Johnson syndrome/toxic epidermal necrolysis, in two of which carbamazepine was implicated. Most patients experienced ADRs associated with aromatic antiepileptics (84.4 %) or older generation antiepileptics (81.3 %). SIGNIFICANCE: This is the first study to assess the relationship between ADRs and antiepileptics at a tertiary care center in Japan. Based on our results, most patients were prescribed older generation antiepileptics, and most ADR events were linked to the administration of drugs in this category; thus, identification of patients at risk of developing ADRs is critical in order to prevent such events.

HLA-B*51:01 and CYP2C9*3 Are Risk Factors for Phenytoin-Induced Eruption in the Japanese Population: Analysis of Data From the Biobank Japan Project.

CYP2C9*3 and HLA-B alleles are reportedly associated with phenytoin-induced eruption in some East Asian populations; however, this finding is not readily applicable to the Japanese population. Thus, we aimed to investigate the risk alleles using samples and data from BioBank Japan. A total of 747 patients (24 cases and 723 tolerant controls) were selected for analysis. Case-control association studies were conducted, using CYP2C9*3, CYP2C9*27, CYP2C19*2, CYP2C19*3, and HLA-B allele genotype data. CYP2C9*3 carrier status was significantly associated with phenytoin-induced eruption (P = 0.0022, odds ratio 7.05, 95% confidence interval, 2.44-20.4). HLA-B*51:01 showed the most prominent association (P = 0.010, odds ratio 3.19, 95% confidence interval, 1.37-7.48). Including both of these features improved predictive performance, measured as area under the receiver operating characteristic curve, by 10%. CYP2C9*3 and HLA-B*51:01 allele carrier statuses are significantly associated with phenytoin-induced eruption; thus, checking this carrier status before prescription would decrease the incidence of phenytoin-induced eruption in clinical practice.

Receptor occupancy theory-based analysis of interindividual differences in antiemetic effects of 5-HT3 receptor antagonists.

BACKGROUND: The aim of this study was to estimate interindividual differences in the antiemetic effects of 5-HT(3) receptor antagonists by evaluating the influence of pharmacokinetics on 5-HT(3) receptor occupancies, based on receptor occupancy theory. METHODS: We analyzed interindividual differences of 5-HT(3) receptor occupancies and antiemetic effects after the oral and/or intravenous administration of standard doses of the following 5-HT(3) receptor antagonists: azasetron, granisetron, indisetron, ondansetron, ramosetron, and tropisetron. RESULTS: The interindividual difference between maximum and minimum 5-HT(3) receptor occupancies after oral administration ranged from 0.6% to 64.0%, and that difference after intravenous administration ranged from 0.6% to 29.6%. Following oral administration, the interindividual difference between maximum and minimum complete vomiting inhibition rates ranged from 0.2% to 16.1%. After intravenous administration, that difference ranged from 0.8% to 52.5%. CONCLUSION: Interindividual differences in the clinical effects of 5-HT(3) receptor antagonists could be evaluated based on receptor occupancy theory, and the differences varied among drugs. Drug selection considering these individual variations might be useful for the patients who experienced vomiting associated with chemotherapy.

Single nucleotide polymorphisms of 17beta-hydroxysteroid dehydrogenase type 7 gene: mechanism of estramustine-related adverse reactions?

OBJECTIVES: To investigate the influence of single nucleotide polymorphisms (SNP) on transcription of the 17beta-hydroxysteroid dehydrogenase (HSD17B7) gene. METHODS: Luciferase reporter genes containing a 5'-flanking of the HSD17B7 gene, as well as the sequence around the SNP, were transfected into LNCaP and DU145 cells. Then, luciferase assays were carried out. RESULTS: The presence of the G allele resulted in an increase of transcriptional activity derived from the 5'-flanking region of the HSD17B7 gene by 270% and 370% in LNCaP and DU145 cells, respectively. Transcriptional activity of the HSD17B7 gene containing the G allele was higher than that of the C allele. CONCLUSIONS: The transcriptional activity of the HSD17B7 gene containing the G allele is higher than that of the C allele. This difference in HSD17B7 expression may regulate the risk of peripheral edema as an adverse reaction induced by estramustine phosphate sodium.

Empirical evaluation of variant calling accuracy using ultra-deep whole-genome sequencing data.

In the design of whole-genome sequencing (WGS) studies, sequencing depth is a crucial parameter to define variant calling accuracy and study cost, with no standard recommendations having been established. We empirically evaluated the variant calling accuracy of the WGS pipeline using ultra-deep WGS data (approximately 410×). We randomly sampled sequence reads and constructed a series of simulation WGS datasets with a variety of gradual depths (n = 54; from 0.05× to 410×). Next, we evaluated the genotype concordances of the WGS data with those in the SNP microarray data or the WGS data using all the sequence reads. In addition, we assessed the accuracy of HLA allele genotyping using the WGS data with multiple software tools (PHLAT, HLA-VBseq, HLA-HD, and SNP2HLA). The WGS data with higher depths showed higher concordance rates, and >13.7× depth achieved as high as >99% of concordance. Comparisons with the WGS data using all the sequence reads showed that SNVs achieved >95% of concordance at 17.6× depth, whereas indels showed only 60% concordance. For the accuracy of HLA allele genotyping using the WGS data, 13.7× depth showed sufficient accuracy while performance heterogeneity among the software tools was observed (the highest concordance of 96.9% was observed with HLA-HD). Improvement in HLA genotyping accuracy by further increasing the depths was limited. These results suggest a medium degree of the WGS depth setting (approximately 15×) to achieve both accurate SNV calling and cost-effectiveness, whereas relatively higher depths are required for accurate indel calling.

[Clinical evaluation of antiemetic effects of 5-hydroxytryptamine receptor type 3 (5HT3 receptor) antagonists based on changes in eating condition in cancer patients receiving chemotherapy].

To evaluate the antiemetic effects of 5-HT(3) receptor antagonists, we investigated the relationship between condition of food intake and occurrence of nausea and vomiting. We collected data such as sex, age, disease, combination of steroids and central antiemetic agents, eating condition, and vomiting condition from medical records in 33 hematologic cancer patients receiving chemotherapy; combination with 5-HT(3) receptor antagonists. The conditions of food intake and nausea/vomiting were checked at 4 mealtime points (lunch, supper, breakfast, and next lunch) after chemotherapy, and were recorded as 1, 3, or 5 as each condition score. To calculate eating scores and nausea/vomiting scores, the sum of scores from 4 mealtime points was used. We found a significant negative correlation between eating scores and nausea/ vomiting scores (n=62, p<0.01). At eating points in which combination therapy with steroids and central antiemetic agents was not given, antiemetic effects of granisetron, azasetron and ramosetron were compared and revealed that azasetron was the most effective antiemetic agent. This result is in agreement with our previous study predicting antiemetic effects of 5-HT(3) receptor antagonists based on the receptor occupancy theory. This study suggests that eithes receptor occupancy or eating score is a useful indicator for assessment of the efficacy of 5-HT(3) receptor antagonists.

Variants at HLA-A, HLA-C, and HLA-DQB1 Confer Risk of Psoriasis Vulgaris in Japanese.

Psoriasis vulgaris (PsV) is an autoimmune disease of skin and joints with heterogeneity in epidemiologic and genetic landscapes of global populations. We conducted an initial genome-wide association study and a replication study of PsV in the Japanese population (606 PsV cases and 2,052 controls). We identified significant associations of the single nucleotide polymorphisms with PsV risk at TNFAIP3-interacting protein 1and the major histocompatibility complex region (P = 3.7 × 10-10 and 6.6 × 10-15, respectively). By updating the HLA imputation reference panel of Japanese (n = 908) to expand HLA gene coverage, we fine-mapped the HLA variants associated with PsV risk. Although we confirmed the PsV risk of HLA-C*06:02 (odds ratio = 6.36, P = 0.0015), its impact was relatively small compared with those in other populations due to rare allele frequency in Japanese (0.4% in controls). Alternatively, HLA-A*02:07, which corresponds to the cysteine residue at HLA-A amino acid position 99 (HLA-A Cys99), demonstrated the most significant association with PsV (odds ratio = 4.61, P = 1.2 × 10-10). In addition to HLA-A*02:07 and HLA-C*06:02, stepwise conditional analysis identified an independent PsV risk of HLA-DQß1 Asp57 (odds ratio = 2.19, P = 1.9 × 10-6). Our PsV genome-wide association study in Japanese highlighted the genetic architecture of PsV, including the identification of HLA risk variants.

Association of HLA-A*31:01 Screening With the Incidence of Carbamazepine-Induced Cutaneous Adverse Reactions in a Japanese Population.

Importance: Carbamazepine, a commonly used antiepileptic drug, is one of the most common causes of cutaneous adverse drug reactions (cADRs) worldwide. The allele HLA-A*31:01 is reportedly associated with carbamazepine-induced cADRs in Japanese and European populations; however, the clinical utility of HLA-A*31:01 has not been evaluated. Objective: To assess the use of HLA-A*31:01 genetic screening to identify Japanese individuals at risk of carbamazepine-induced cADRs. Design, Setting, and Participants: This cohort study was conducted across 36 hospitals in Japan from January 2012 to November 2014 among 1202 patients who had been deemed suitable to start treatment with carbamazepine. Preemptive HLA-A*31:01 genetic screening was performed for 1187 participants. Patients who did not start treatment with carbamazepine or alternative drugs were excluded. Participants were interviewed once weekly for 8 weeks to monitor the development of cADRs. Data analysis was performed from June 8, 2015, to December 27, 2016. Exposures: Neuropsychiatrists were asked to prescribe carbamazepine for patients who tested negative for HLA-A*31:01 and alternative drugs for those who tested positive for HLA-A*31:01. Main Outcomes and Measures: Incidence of carbamazepine-induced cADRs. Results: Of the 1130 included patients who were prescribed carbamazepine or alternative drugs, the mean (range) age was 37.4 (0-95) years, 614 (54.3%) were men, and 198 (17.5%) were positive for HLA-A*31:01. Expert dermatologists identified 23 patients (2.0%) who had carbamazepine-induced cADRs, of which 4 patients required hospitalization. Drug-induced hypersensitivity syndrome was observed for 3 patients, maculopapular eruption for 9 patients, erythema multiforme for 5 patients, and an undetermined type of cADR for 6 patients. No patient developed Stevens-Johnson syndrome or toxic epidermal necrolysis. Compared with historical controls, the incidence of carbamazepine-induced cADRs was significantly decreased (for BioBank Japan data: incidence, 3.4%; odds ratio, 0.60; 95% CI, 0.36-1.00; P = .048; for the Japan Medical Data Centre claims database: incidence, 5.1%; odds ratio, 0.39; 95% CI, 0.26-0.59; P < .001). Conclusions and Relevance: Preemptive HLA-A*31:01 genetic screening significantly decreased the incidence of carbamazepine-induced cADRs among Japanese patients, which suggests that it may be warranted in routine clinical practice.

Theory based analysis of anti-inflammatory effect of infliximab on Crohn's disease.

Tumor necrosis factor (TNF)-alpha, a primary mediator of inflammatory responses, is increased in patients with active Crohn's disease (CD) and considered to play an important role in the regulation of inflammation in CD. Infliximab (IFX) is a chimeric murine-human monoclonal IgG1 antibody that targets TNF-alpha and is used as a therapeutic agent for CD. Although that dosage regimen has been established through clinical trial experience, it has not been analyzed theoretically. We analyzed of sequential changes of the Crohn's disease activity index (CDAI) using a pharmacokinetic-pharmacodynamic model integrating the pharmacokinetics of IFX and turnover rate of TNF-alpha. The time course effects of IFX derived from the present model were matched to reported data regarding CDAI ratios, and we found that the clinical effect of IFX reached a maximum value 2 to 4 weeks after administration and was maintained for the next several weeks. Our results suggested that the standard dosage regimen of IFX is theoretically appropriate. Further, based on the results of various dosage regimens, a second administration of IFX 2 weeks after the first dose was shown to achieve remission in the early stage of active CD, when IFX was given as a repeated treatment.

Effects of mouth washing procedures on removal of budesonide inhaled by using Turbuhaler.

Mouth washing after inhalation of corticosteroids is effective for prevention of local adverse effects. We determined the amounts of drug residues remaining on the oropharyngeal mucosa following inhalation of budesonide (BUD) via a Turbuhaler (BUD-TH) (100 microg). Further, we studied the effects of mouth washing on the removal of drug residues by quantification of BUD in expectorated wash solution using an HPLC method. The amount of BUD recovered after gargling and rinsing for 5 s each was 19.4+/-9.4 microg, as compared to 23.8+/-13.6 microg after rinsing alone for 10 s and 18.3+/-8.9 microg after gargling alone for 10 s, though the differences were not significant. Our results indicated that about 20% of the dose was remaining on the oropharyngeal mucosa after inhalation. In a comparison of washing times, the amounts of BUD recovered were 26.3+/-3.2 microg after gargling and rinsing for 3 s each, and 19.4+/-9.3 microg after those for 5 s each. As for the effect of lag time before beginning mouth washing, the ratio of BUD recovered following mouth washing with a lag time of 1 min was 73.2%, while it was reduced to 27.8% after 10 min, as compared to immediate mouth washing following administration. Our results suggest that the amount of BUD removed by mouth washing is associated with the lag time between inhalation and mouth washing, however, not with the duration of mouth washing. We concluded that immediate mouth washing after inhalation is most useful for the removal of drugs following BUD-TH administration.

[Effectiveness of network meeting system following practical pharmacy training].

We established a network meeting system program and used it to review a prior pharmaceutical practice training session. Pharmacists at Tokai University Hachioji Hospital gave lectures about dispensing and other tasks performed by clinical pharmacists to third-year undergraduate students at Tokyo University of Pharmacy and Life Sciences. After the lectures, discussions were held using the network meeting system, after which a questionnaire was completed by the students. The questionnaire was answered by 530 students, of whom approximately 90% expressed interest in the program, 80% noted approval of the media used in the system, and 94% thought that the program was useful. Thus, we concluded that the students were motivated by the program to remember what they had learned in the lectures. We also found that the quality of data communication had an effect on the interests and motivation of the students. Based on their evaluation of the media, it was considered that improvements in communication regarding the system were necessary, though the evaluation of the utility of the program was not influenced by the quality of data communication. As a result, we concluded that our network meeting system program was useful to review prior learning of pharmaceutical practice.

[Analysis of antiemetic effect of various dosage regimens of azasetron hydrochloride based on 5-HT3 receptor occupancy of serotonin].

Antineoplastic drugs have been shown to exert direct effects on the gut and induce the release of serotonin from the enterochromaffin cells of small intestinal mucosa. It is thought that released serotonin stimulates vagal afferent fibers through 5-HT3 receptors located in the vagal afferent terminals in the gastrointestinal tract and initiates sensory signals to the area postrema and the emetic center, thereby initiating nausea and vomiting. A 5-HT3 antagonist competitively inhibits serotonin at its specific binding sites, 5-HT3 receptors, and thereby elicits an antiemetic effect. Therefore 5-HT3 receptor occupancy of serotonin may be an appropriate indicator of the antiemetic activity of 5-HT3 antagonists. We analyzed 5-HT3 receptor occupancy of serotonin by integrating pharmacokinetic and receptor-binding kinetic parameters based on the receptor occupancy theory to compare the strength of the antiemetic effects of three dosage regimens of azasetron hydrochloride. The inhibitory effects on the binding of serotonin to 5-HT3 receptor of regimen 2 (an intravenous bolus injection of 5 mg of azasetron hydrochloride before and 8 h after chemotherapy) and regimen 3 (an intravenous bolus injection of 2.5 mg followed by 7.5 mg continuous intravenous infusion for 24 h) were longer-lasting than those of regimen 1 (an intravenous bolus injection of 10 mg before the start of chemotherapy). Furthermore, a positive relationship was found between the time of inhibitory effects on the binding of serotonin to 5-HT3 receptor and antiemetic effects of azasetron hydrochloride. From these results, dosage regimens 2 and 3 were considered to be more effective in the long term than regimen 1 in prophylaxis of nausea and vomiting induced by cisplatin.