Tolerability of Erythrocyte Ribavirin Triphosphate Concentrations Depends on the ITPA Genotype.

BACKGROUND: Ribavirin (RBV) is an antiviral drug that is part of the current standard therapy for chronic hepatitis C (CHC). It is enzymatically converted to ribavirin triphosphate (RTP) that inhibits the activity of viral RNA polymerase, thereby preventing viral replication. However, one of its adverse effects includes hemolytic anemia that limits its application. The variant of ITPA (inosine triphosphatase), which dephosphorylates inosine triphosphate to inosine monophosphate, is a protective factor for RBV-induced anemia. RTP is an important metabolite required for ribavirin action. This study evaluated the time-dependent association of RTP concentrations in erythrocytes, RBV-induced toxicity, and virological response to RBV treatment for hepatitis C. METHODS: A total of 28 Japanese patients with CHC were treated with RBV/peg-interferon/simeprevir or RBV/sofosbuvir and were genotyped for ITPA variants (rs1127354 and rs7270101). We measured RTP concentrations in erythrocytes in a total of 76 samples collected at 4, 8, and 12 weeks from the initiation of treatment. RESULTS: The ITPA rs1127354 variant was found in 7 patients. This was associated with significantly higher RTP concentrations in erythrocytes than in the wild-type patients (P < 0.001). Moreover, a significant correlation was observed between RTP concentrations and decline in hemoglobin (Hb) levels from baseline values in ITPA wild type and rs1127354 variant 12 weeks after treatment initiation (P < 0.01; r = -0.618 and -0.967, respectively). Multiple regression analysis revealed that ITPA genotype and erythrocyte RTP concentrations were major factors associated with reduced Hb levels in RBV therapy for CHC. However, we did not find any association between erythrocyte concentrations and virological response. CONCLUSIONS: The increased tolerability to RTP concentrations in erythrocytes in the ITPA variant rs1127354 plays a role in preventing RBV-induced severe anemia in this ITPA variant.

Rapidity and Severity of Hemoglobin Decreasing Associated with Erythrocyte Inosine Triphosphatase Activity and ATP Concentration during Chronic Hepatitis C Treatment.

The purpose of this study was to evaluate the association between therapy-induced hemoglobin (Hb) decreasing rapidity and severity with erythrocyte inosine triphosphatase (ITPase) activity and ATP concentration in chronic hepatitis C patients receiving chronic hepatitis C (HCV) treatment. Forty-three Japanese patients were included in the study. Erythrocyte ITPase activity before therapy was determined by HPLC-UV. Erythrocyte ATP concentrations before and during therapy were determined by luciferase assay. Genotyping for ITPA 94C>A (rs1127354) and IVS2+21 A>C (rs7270101) was conducted using TaqMan probes. The median ITPase activity (µmol/h/g hemoglobin) of ITPA 94 CC, CA, and AA genotypes was 136.8 (range, 80.4-289.6), 41.1 (24.3-93.1), and 11.8, respectively. ITPase activity and Hb decreasing showed a significantly inverse relationship at therapeutic weeks 2, 4, and 6 (p<0.01). Erythrocyte ATP concentration was decreased by therapy, and Hb decreasing was significantly and inversely correlated with erythrocyte ATP concentration at week 4 and after week 8 (p<0.001 and 0.05, respectively). ATP concentration for patients with ITPA 94CA was significantly lower than ITPA 94CC at week 4 (p=0.045). We concluded that ITPase activity plays an important function and that ATP concentration changes due to therapy are related to the Hb decreasing mechanism in the early period of therapy with HCV treatment.

Susceptibility to 6-MP toxicity conferred by a NUDT15 variant in Japanese children with acute lymphoblastic leukaemia.

Genotyping of TPMT prior to 6-mercaptopurine (6-MP) administration in acute lymphoblastic leukaemia (ALL) patients has been integrated into clinical practice in some populations of European ancestry. However, the comparable rates of 6-MP myelotoxicity, but rarity of TPMT variants, in Asians suggest that major determinants have yet to be discovered in this population. We genotyped 92 Japanese paediatric ALL patients for NUDT15 rs116855232, a 6-MP toxicity-related locus discovered in Asians. Logistic regression and survival analysis were used to evaluate its association with leucopenia, hepatotoxicity, 6-MP dose reduction, therapy interruption and event-free survival. The allele frequency of rs116855232 was 0·16, and leucopenia was more common in carriers of the T allele (odds ratio, 7·20; 95% confidence interval, 2·49-20·80; P = 2·7 × 10(-4) ). As leucopenia results in 6-MP dose reduction, we observed average doses during maintenance therapy of 40·7, 29·3 and 8·8 mg/m(2) for patients with CC, CT and TT genotypes, respectively (P < 0·001). Hepatotoxicity was observed only in CC genotype patients. Event-free survival did not significantly differ by NUDT15 genotype. rs116855232 is an important determinant of 6-MP myelotoxicity in Japanese children with ALL and may represent the most robust toxicity-related locus in Asians to date. Considerations for clinical application may be warranted.

Pharmacokinetics and postoperative analgesia of epidural tramadol: A prospective, pilot study.

BACKGROUND: Tramadol, a centrally acting analgesic drug, can be administered via multiple routes and is generally well tolerated. OBJECTIVE: This study was designed to assess the pharmacokinetics of epidural tramadol administered preoperatively in Japanese patients undergoing upper abdominal surgery. METHOD: Japanese patients who were scheduled to undergo upper abdominal surgery in The Kitasato Institute Hospital, Tokyo, Japan, were included. Patients received tramadol 2 mg/kg with 5 mL of 1% mepivacaine epidurally 10 minutes before incision. The serum concentration of tramadol was determined by high-performance liquid chromatography for 21 hours after administration. Serum concentration was determined before tramadol administration and 10, 20, 30, and 60 minutes after tramadol administration, first postoperative night, and first postoperative day. Pain score and adverse events (AEs) were assessed at 1, 3, 6, 12, 18, 24, 36, and 48 hours after surgery by patient interview. RESULTS: Eleven patients were assessed for enrollment. Seven patients (6 men, 1 woman; mean [SD] age, 61.3 [12.6] years; mean [SD] weight, 59.9 [8.9] kg) provided consent and completed the study. The mean (SD) serum Cmax of tramadol was 1385.5 (390.8) ng/mL, Tmax was 0.33 (0.22) hour, and terminal elimination half-life (t1/2ß) was 10.5 (2.3) hours. Four patients complained of nausea; however, only 1 patient was administered an antiemetic. No other AEs were reported. CONCLUSION: This pilot study found that epidural tramadol administered before incision induced a Cmax within 30 minutes of administration. The drug was detected in serum at ∼21 hours after surgery.

Clinical Pharmacy Education in Japan: Using Simulated Patients in Laboratory-Based Communication-Skills Training before Clinical Practice.

The Japanese pharmaceutical curriculum was extended from four to six years in 2006. Students now receive practical communication-skills training in their fourth year, before progressing to train in hospital and community pharmacies in their fifth year. Kitasato University School of Pharmacy, Tokyo, had established a program to meet these aims before the 2006 guidance. In the present study, we discuss and evaluate the features of this communication-skills training program. This study enrolled 242 fourth-year pharmacy students at Kitasato University. Students filled out a questionnaire survey after completing the laboratory element of their undergraduate education. As part of training, students were asked to obtain patient data from a model medical chart, before performing simulated patient interviews covering hospital admission and patient counseling. These simulations were repeated in a small group, and feedback was provided to students by both the simulated patient and the faculty after each presentation. It was found that students were able to develop their communication skills through this approach. Thus, an effective system of gradual and continuous training has been developed, which allows students to acquire clinical and practical communication skills.

Clinical application of the leukocyte migration test and new diagnostic criteria for identifying causative agents in patients with drug-induced liver injury.

BACKGROUND/AIMS: We examined the usefulness of the leukocyte migration test (LMT) in the identification of agents causing drug-induced liver injury (DILI). METHODOLOGY: In 14 patients who were tentatively diagnosed as having DILI in Kitasato Institute Hospital, pharmacists collected and evaluated drug information and patients' medication histories to identify causative agents. Simultaneously, LMT and drug lymphocyte stimulation test (DLST) were performed. Furthermore, scoring was performed according to the diagnostic criteria established by the International Consensus Meeting (ICM) and the Digestive Disease Week-Japan 2004 (DDW-J). RESULTS: LMT-positive agents showed a higher ICM score compared to DLST-positive agents. The rate of LMT-positive agents was examined with respect to ICM assessment, and 0%, 25%, 33%, and 100% of agents regarded as unrelated/unlikely, possible, probable, and highly probable showed positive reactions on LMT, respectively; the rate of LMT-positive agents increased with the degree of the agent's involvement. When the results of LMT were applied to the DDW-J criteria, there was a correlation with the ICM criteria in comparison to scoring based on the results of DLST. CONCLUSIONS: LMT may be useful for identifying agents causing DILI. Furthermore, the collection and evaluation of drug and patient information and in vitro testing in the identification of causative agents may support more reliable diagnosis.

Cluster analysis of pharmacists' work attitudes.

Background: Few studies in Japan use clustering to examine the work attitudes of pharmacists. This study conducts an exploratory analysis to classify those attitudes based on previous studies to help staff pharmacists and their management to understand their mutually beneficial requirements. Methods: Survey data collected in previous studies from 1 228 community pharmacists and 419 hospital pharmacists were analyzed using Quantification Theory 3 and clustering. Results: Among community pharmacists, two clusters, namely 30- to 34-year-old married males and married males aged over 35 years, reported the highest job satisfaction, intending to remain in their jobs for 5 years or more or until retirement. Conversely, one cluster of 35- to 39-year-old single females reported the lowest job satisfaction and intended to remain for less than 5  years or were undecided. Among hospital pharmacists, one cluster of 22- to 25-year-old single males reported the highest job satisfaction and intended to remain for more than 5 years. Conversely, one cluster of 30- to 34-year-old married males reported the lowest job satisfaction and a period of working undetermined. Conclusions: This study used clustering to explore how pharmacists of different ages, marital statuses, and experience felt regarding their work. Job satisfaction and human relationships are significant in considering future work plans of practicing pharmacists. Pharmacy staff, supervisors, and managers of community or hospital pharmacies must recognize features of pharmacists' work attitudes for offering high-quality service to patients.

Collection of medical drug information in pharmacies: Drug Event Monitoring (DEM) in Japan.

To establish a system for collecting and reporting information from community pharmacists such as that on adverse effects, the Japan Pharmaceutical Association (JPA) conducts Drug Event Monitoring (DEM). In the fiscal year 2002, a survey was carried out to clarify the incidence of sleepiness due to antiallergic drugs. The investigated active ingredients were ebastine, fexofenadine hydrochloride, cetirizine hydrochloride, and loratadine. Community pharmacists asked the following question to patients who visited their pharmacies: "Have you ever become sleepy after taking this drug?" During a 4-week survey period, reports of 94256 cases were collected. To evaluate the incidence of sleepiness, we analyzed cases in which reports showed alleged absence of concomitant oral drugs, and drug use in conformity with the dose and method described in package inserts. The incidence of sleepiness was significantly different among the drugs (chi(2)-test, p<0.001). The observed incidences of sleepiness due to the drugs (8.8-20.5%) were higher than those described in each package insert (1.8-6.35%). This may be because an active question was used ("Have you ever become sleepy after taking this drug?"). Active intervention by pharmacists may be useful for collecting more information on improvement in the QOL of patients and safety. In addition, the pharmacists were asked to report events other than "sleepiness" in the free description column of the report. Some symptoms not described in the package inserts were reported, suggesting that DEM may lead to the discovery of new adverse effects. These results suggest that community pharmacists have a good opportunity to collect information in DEM, and safety information such as that on adverse effects can be obtained from pharmacies.

Differential induction of serum interleukin-6 and -12 by interferon-alpha and -beta administration in chronic hepatitis C patients.

Interferon (IFN) is widely used to manage chronic hepatitis C virus (HCV) infections. It contributes to the production of various cytokines, and alters cytokine interactions in vivo. Among them, interleukin (IL)-12, is thought to shift the immune system to Th-1 dominance and to, therefore, have a beneficial effect on eradication of HCV. On the other hand, IL-6 seems to be related to the acute inflammatory phenomenon, such as fever accompanied with IFN therapy. We studied the time courses of the serum IL-12 and IL-6 levels of patients with HCV infections treated with either IFN-alpha or IFN-beta. On the first day, both IFN-alpha and IFN-beta significantly induced serum IL-6, but when the administration was repeated, the serum IL-6 levels gradually decreased in both the IFN-alpha and the IFN-beta groups. The serum IL-6 levels correlated well with the daily peak body temperature of the patients, which also went down with repeated IFN administration. Serum IL-12 production was induced by IFN-alpha not by IFN-beta. The induced IL-12 decreased to baseline by repeating IFN-alpha administration. These results suggested that IFN-alpha and IFN-beta induce cytokine production in a different manner, and that their effect on cytokine interactions is short-term and reduced by repeated administration. Therefore, the induction of serum IL-12 production by IFN did not seem to have a critical effect during the early stage of IFN therapy.

Methylenetetrahydrofolate reductase gene haplotypes affect toxicity during maintenance therapy for childhood acute lymphoblastic leukemia in Japanese patients.

Abstract The aim of this study was to investigate the influence of daily 6-mercaptopurine (6-MP) and low-dose weekly methotrexate (MTX) combination treatment and methylenetetrahydrofolate reductase (MTHFR) haplotypes on toxicity during maintenance therapy in Japanese childhood acute lymphoblastic leukemia (ALL). We retrospectively analyzed the MTHFR C677T and A1298C polymorphisms and influence of haplotypes on toxicity in 73 patients. Patients with the MTHFR 677TT and 677CT + 1298AC were associated with severe liver toxicity (p = 0.014, odds ratio [OR] = 3.82, 95% confidence interval [CI] = 1.27-11.46) and more rapid onset of liver toxicity (p = 0.010). Patients with MTHFR 677TT and 677CT + 1298AC were associated with lower frequency of 6-MP and MTX dose reduction due to leukopenia (p < 0.05). No difference was observed in average drug doses in the MTHFR genotypes. In conclusion, the MTHFR C677T and A1298C haplotypes might be useful for monitoring adverse effects in childhood ALL maintenance therapy in Japanese patients.

The activity of the inosine triphosphate pyrophosphatase affects toxicity of 6-mercaptopurine during maintenance therapy for acute lymphoblastic leukemia in Japanese children.

The association between inosine triphosphate pyrophosphatase (ITPA) activity and toxicity of 6-mercaptopurine (6-MP) was retrospectively evaluated in 65 Japanese children with acute lymphoblastic leukemia (ALL). Patients with an ITPA activity of less than 126 µmol/h/gHb presented with hepatotoxicity more frequently than those with higher ITPA activity (p<0.01). The average 6-MP dose during maintenance therapy administered to two patients with the ITPA deficiency was lower than that given to the other patients. Measuring ITPA activity is important for ensuring the safety of maintenance therapy for Asians with ALL because thiopurine S-methyl transferase mutations are rare in the Asian population.

Optimal erythrocyte ribavirin level to reduce the risk of anemia and obtain an early virological response in patients with chronic hepatitis C caused by genotype 1b infection.

Aims. To determine whether the erythrocyte phosphorylated ribavirin (RBV) level might be a useful index of EVR and risk of anemia and to determine the optimal dose of RBV in 24 patients with hepatitis C with pegylated interferon and RBV. Methodology. The RBV level was measured by a high-performance liquid chromatography. Results and Conclusion. In patients aged 50 years or over, a negative correlation (r = -0.548, P < .05) was observed between the RBV level at week 2 and rate of Hb reduction (ΔHb) at week 4. The ΔHb at week 4 was significantly greater in patients with RBV levels of ≥800 µM (-25.5 ± 10.1%) than in patients with RBV levels <800 µM (-15.6 ± 7.7%). None of the patients with RBV levels <600 µM at week 2 achieved EVR and SVR. Thus the optimal levels of erythrocyte phosphorylated RBV at week 2 of therapy in order to achieve EVR without anemia seemed to be 600-800 µM.