Trends in tolvaptan prescription and the association between hypernatremia and aging in tolvaptan-treated patients in Japan: Real-world data mining using Japanese databases.

OBJECTIVE: To identify the trends in tolvaptan prescription and the association between aging and tolvaptan-induced hypernatremia. MATERIALS AND METHODS: A health insurance claims database and a spontaneous adverse drug reaction database were used. RESULTS: Of all patients who had been prescribed tolvaptan, the proportion of patients aged 60 - 79 years and ≥ 80 years was consistent at ~ 40%. Moreover, the prescription frequency of tolvaptan increased over time for patients in the same age groups. The adjusted reporting odds ratio of tolvaptan-induced hypernatremia was 5.54 (95% confidence interval, 3.31 - 9.25) in patients aged ≥ 60 years from among all patients and 2.09 (95% confidence interval, 1.59 - 2.75) in those aged ≥ 80 years from among those aged ≥ 60 years. CONCLUSION: It may be necessary to be aware of hypernatremia in elderly patients who are expected to have increased prescriptions of tolvaptan.

Association between sodium-glucose cotransporter 2 inhibitors and pancreatic cancer in the Japanese working-age population.

OBJECTIVE: Pancreatic cancer-related mortality is increasing worldwide, and prevention methods and effective novel therapies are required. In pancreatic cancer, sodium-glucose cotransporters (SGLT) are involved in glucose uptake. This study aimed to clarify the association between SGLT2 inhibitors and pancreatic cancer development. MATERIALS AND METHODS: A nested case-control study was conducted using the JMDC administrative claims database (January 2005 to June 2020). Patients newly diagnosed with type 2 diabetes mellitus (T2DM) were included, and cases were defined as patients who developed pancreatic cancer. Patients with outcomes were randomly matched to a maximum of 20 controls according to age (± 5 years), sex, and calendar date (month and year) of the first T2DM diagnosis through risk set sampling. RESULTS: Of the 181,107 T2DM patients, 363 cases and 7,043 controls were selected with 14 and 457 patients prescribed SGLT2 inhibitors, respectively. Cumulative administration of SGLT2 inhibitors for > 180 days was significantly inversely associated with the development of pancreatic cancer (adjusted odds ratio: 0.58, 95% confidence interval: 0.31 - 0.99). CONCLUSION: SGLT2 inhibitors may reduce the risk of developing pancreatic cancer in T2DM patients. The number of patients over 65 years of age was small in this study due to the nature of the data source. Further studies with larger sample sizes including older patients are needed.

Risk Assessment of Neutropenia during Low-Dose Valganciclovir Prophylaxis for Heart Transplant Recipients.

The aim of this study was to investigate whether low-dose valganciclovir (VGCV) prophylaxis for cytomegalovirus (CMV) infection increased the risk of developing neutropenia in heart transplant recipients (HTRs). Forty-three HTRs receiving VGCV were divided into two groups: those who received VGCV prophylaxis (n = 22) and those who did not (n = 21). Neutropenia was defined as an absolute neutrophil count ˂1500/µL and was monitored for approximately one year post-transplantation. In the prophylaxis group, 77.3% (17/22) of HTRs experienced neutropenia, which was significantly higher than that in the no prophylaxis group (42.9% [9/21], p = 0.031). No significant differences in the duration of VGCV administration and cumulative dose up to the first neutropenia episode were observed between the groups. Meanwhile, the cumulative dose of mycophenolate mofetil was significantly higher in the prophylaxis group than in the no prophylaxis group (p = 0.018); the daily maintenance dose and regularly measured area under the concentration-time curve (AUC) of mycophenolic acid did not significantly differ between groups. In conclusion, the risk of developing neutropenia was higher in HTRs receiving low-dose VGCV prophylaxis than it was in those not receiving prophylaxis, probably not attributed to dosing period and cumulative dose of VGCV until the onset of neutropenia.

Effect of mammalian-target-of-rapamycin inhibitors on the cancer risk in patients receiving calcineurin inhibitors: Data mining of a spontaneous reporting database.

OBJECTIVE: Calcineurin inhibitors (CNIs), including cyclosporine and tacrolimus, are associated with an increased cancer risk. However, whether mammalian target of rapamycin inhibitors (mTORis), including sirolimus and everolimus, decrease the cancer risk in patients receiving CNIs remains uncertain. We aimed to determine whether mTORis are associated with a decreased cancer risk in patients receiving CNIs using data mining of a spontaneous adverse reaction database. MATERIALS AND METHODS: Disproportionality analysis was conducted using the U.S. Food and Drug Administration Adverse Event Reporting System database (2004 - 2019) with reporting odds ratio and information component being used to indicate a signal. RESULTS: Data subset analyses indicated that sirolimus and everolimus were not associated with a decreased cancer risk in patients receiving cyclosporine or tacrolimus but were associated with an increased risk of nonmelanoma skin cancer (NMSC) and Kaposi's sarcoma. CONCLUSION: mTORis are not associated with a decreased cancer risk but are associated with a further increase in the risk of NMSC and Kaposi's sarcoma in patients receiving CNIs. Further studies are necessary to clarify the mechanism underlying the association between mTORis and NMSC or Kaposi's sarcoma.

Pharmacokinetics and pharmacodynamics of amiodarone in patients with hypertriglyceridemia: Two case reports.

BACKGROUND: The antiarrhythmic drug amiodarone has noncardiac adverse effects, leading to restrictive therapeutic plasma ranges. Despite the significant positive correlation between triglyceride and amiodarone levels, the effect of fluctuations in amiodarone levels in patients with hypertriglyceridemia on amiodarone therapy has not been fully characterized. This study is the first to report on the effect of hypertriglyceridemia on the efficacy and safety of amiodarone therapy. CASE PRESENTATION: The first patient was a 58-year-old man with hypertriglyceridemia who was diagnosed with ventricular fibrillation (patient #1). The second patient with hypertriglyceridemia was a 72-year-old man with sustained ventricular tachycardia (patient #2). Both patients received implantable cardioverter-defibrillator therapy. During the study period, amiodarone and N-desethylamiodarone concentrations were measured 12 times in patient #1 and 26 times in patient #2. Triglyceride concentrations in patient #1 and patient #2 ranged from 102 to 765 mg/dL and from 125 to 752 mg/dL, respectively. For both patients, amiodarone dosage was maintained at 100 mg/day, and the administration of concomitant drugs that could affect amiodarone pharmacokinetics was neither initiated nor discontinued. However, amiodarone concentrations fluctuated (patient #1, 0.52 - 1.86 µg/mL; patient #2, 0.73 - 2.82 µg/mL). Although amiodarone concentrations fluctuated, neither of the patients had defibrillation shocks to stop the abnormal rhythm via an implantable cardioverter-defibrillator, and laboratory data showed that thyroid-stimulating hormone, free thyroxine, KL-6, and surfactant protein-D remained close to normal. CONCLUSION: In patients with hypertriglyceridemia, it may be necessary for clinicians to pay more attention to the clinical symptoms along with fluctuations in amiodarone levels and accordingly adjust amiodarone dosage.

Discontinuation of oral amphotericin B therapy does not influence the pharmacokinetics of tacrolimus in heart transplant patients.

OBJECTIVE: Amphotericin B (AMPH-B) is used to prevent opportunistic infections associated with immunosuppressive therapy after heart transplantation (HTx), while the blood concentrations of tacrolimus (TAC) are carefully controlled. Although AMPH-B has the potential to inhibit TAC metabolism in in vitro studies, its interaction with clinically used AMPH-B oral suspension has not been investigated. In the present study, we examined whether oral AMPH-B therapy influences the pharmacokinetics of TAC in HTx patients. MATERIALS AND METHODS: A retrospective study was performed at the National Cerebral and Cardiovascular Center in Japan. All patients with HTx enrolled in the study received standard triple-drug immunosuppression therapy including the regular release of TAC, mycophenolate mofetil, and prednisolone as well as prophylactic therapy with AMPH-B oral suspension. Patient characteristics and clinical laboratory data were collected from the electronic medical record system. Blood concentrations of TAC were used for pharmacokinetic analysis. RESULTS: A total of 14 patients were enrolled in the study. There were no statistically significant differences in the variables except for serum creatinine levels and eGFR before and after discontinuation of oral AMPH-B therapy. The dose and trough concentrations of TAC and the area under the time-concentration curve and apparent oral clearance calculated from its concentrations were not influenced by discontinuation of AMPH-B treatment. CONCLUSION: The prophylactic treatment with AMPH-B oral suspension did not influence the pharmacokinetics of TAC and was demonstrated as a safe and easy method to prevent early post-HTx fungal infection.

Drug interactions between tacrolimus and clotrimazole troche: a data mining approach followed by a pharmacokinetic study.

PURPOSE: This study investigated the effects of clotrimazole troche on the risk of transplant rejection and the pharmacokinetics of tacrolimus. METHODS: The data mining approach was used to investigate whether the use of clotrimazole increased the risk of transplant rejection in patients receiving tacrolimus therapy. Patient data were acquired from the US Food and Drug Administration's Adverse Event Reporting System (FAERS) from the first quarter of 2004 to the end of 2017. Next, we retrospectively investigated the effect of clotrimazole troche on tacrolimus pharmacokinetics in seven patients who underwent heart transplantation between March and December 2017. RESULTS: The FAERS subset data indicated a significant association between transplant rejection and tacrolimus with clotrimazole [reporting odds ratio 1.92, 95% two-sided confidence interval (95% CI) 1.43-2.58, information component 0.81, 95% CI 0.40-1.23]. The pharmacokinetic study demonstrated a significant correlation between trough concentration (C0) and area under the concentration-time curve of tacrolimus after discontinuation of clotrimazole (R2 = 0.60, P < 0.05) but not before its discontinuation. Furthermore, the median clearance/bioavailability of tacrolimus after discontinuation of clotrimazole was 2.2-fold greater than that before its discontinuation (0.27 vs. 0.59 L/h/kg, P < 0.05). The median C0 decreased from 10.7 ng/mL on the day after discontinuation of clotrimazole to 6.5 ng/mL at 1 day and 5.3 ng/mL at 2 days after its discontinuation. CONCLUSION: Immediate dose adjustments of tacrolimus may be beneficial to avoid transplant rejection when clotrimazole troche is added or discontinued.

Effects of clotrimazole on tacrolimus pharmacokinetics in patients with heart transplants with different CYP3A5 genotypes.

PURPOSE: This study aimed to investigate the effects of clotrimazole on the pharmacokinetics of tacrolimus in Japanese patients with heart transplants with different CYP3A5 genotypes. METHODS: Twenty-six patients who underwent heart transplantation between June 2012 and July 2017 were enrolled in this retrospective study. The CYP3A5 (rs776746; CYP3A5*3) genotype was determined after monitoring and analysing tacrolimus blood concentrations. The pharmacokinetic profile of tacrolimus was examined before and after the discontinuation of clotrimazole and in patients with different CYP3A5 genotypes. RESULTS: The CYP3A5*1/*1, *1/*3 and *3/*3 genotypes were detected in 2, 8 and 16 patients, respectively. After clotrimazole was discontinued, the CYP3A5 expresser (CYP3A5*1/*1 or *1/*3) group had a 3.3-fold median increase in apparent oral clearance of tacrolimus (0.27 vs. 0.89 L/h/kg, P = 0.002) compared with the CYP3A5 non-expresser (CYP3A5*3/*3) group with a 2.2-fold median increase (0.18 vs. 0.39 L/h/kg, P < 0.0001). Significant correlations were observed between C0 and area under the concentration-time curve (AUC0-12) of tacrolimus after the discontinuation of clotrimazole in the CYP3A5 expresser and non-expresser groups, respectively (R2 = 0.49 and 0.42, all P < 0.05), but not before the discontinuation of clotrimazole. CONCLUSION: The effects of clotrimazole on tacrolimus pharmacokinetics in the CYP3A5 expresser patients were significantly greater than those in the CYP3A5 non-expresser patients. In addition, clotrimazole disturbed the correlation between C0 and AUC0-12 of tacrolimus. Careful dose adjustment of tacrolimus based on CYP3A5 genotypes may be beneficial for the patients with heart transplants who are concomitantly treated with clotrimazole.

Comparison of CYP3A5*3 genotyping assays for personalizing immunosuppressive therapy in heart transplant patients
.

OBJECTIVE: This study aimed to compare a novel point-of-care assay that involves a flap endonuclease reaction performed using GTS-7000® to a conventional assay that involves DNA sequencing performed using 3130xl Genetic Analyzers*. MATERIALS AND METHODS: This study enrolled 74 patients who underwent heart transplantation at the National Cerebral and Cardiovascular Center between May 2004 and October 2016. Each patient was genotyped as cytochrome P450 (CYP) 3A5*1/*1, -CYP3A5*1/*3, or CYP3A5*3/*3. Quantitative and qualitative comparison between the two assays was carried out. RESULTS: Four patients were genotyped as CYP3A5*1/*1, 25 as CYP3A5*1/*3, and 45 as CYP3A5*3/*3. Genotyping results of the point-of-care method were completely consistent with those of the conventional method. The total analysis time of the point-of-care method was shorter than that of the conventional method (~ 1.5 vs. 7.5 h). However, the cost of the point-of-care method was higher than that of the conventional method (~ 21 vs. 17 US$). CONCLUSION: Compared with a laboratory-based assay, the point-of-care assay that utilizes GTS-7000® is accurate and rapid despite being slightly more expensive. Further trials using this assay are warranted.

Effects of vitamin K epoxide reductase complex 1 gene polymorphisms on warfarin control in Japanese patients with left ventricular assist devices (LVAD).

PURPOSE: This study aimed to investigate relationships between times in therapeutic range (TTR) or warfarin sensitivity indexes (WSI) and VKORC1-1639G>A and CYP2C9 polymorphisms in patients with left ventricular assist devices (LVAD). METHODS: Severe heart failure patients who received LVAD from January 1, 2013 to October 31, 2017 were recruited. Relationships between TTR or WSI and VKORC1-1639G>A and CYP2C9 gene polymorphisms were investigated immediately after LVAD implantation (period 1) and immediately prior to hospital discharge (period 2). RESULTS: Among 54 patients, 31 (72.1%) had VKORC1-1639AA and CYP2C9*1/*1 (AA group) polymorphisms and 12 (27.9%) had VKORC1-1639GA and CYP2C9*1/*1 (GA group) polymorphisms. During period 1, mean prothrombin time-international normalized ratio (PT-INR) values were significantly higher in the AA group than in the GA group (2.21 vs. 2.05, p < 0.0001). Mean WSI values were 1.68-fold greater in the AA group than in the GA group (1.14 vs. 0.68, p < 0.0001). In addition, times below the therapeutic range (TBTR) in the GA group were significantly greater than in the AA group during period 1 (39.8 vs. 28.3%, p = 0.032), and insufficient PT-INR was more frequent in the GA group than in the AA group. However, mean PT-INR values during period 2 did not differ and no significant differences in TTR, TATR, and TBTR values were identified. In subsequent multivariable logistic regression analyses, the VKORC1-1639GA allele was significantly associated with insufficient anticoagulation. CONCLUSION: Patients with the VKORC1-1639GA and CYP2C9*1/*1 alleles may receive insufficient anticoagulation therapy during the early stages after implantation of LVAD, and VKORC1-1639G>A and CYP2C9 genotyping may contribute to more appropriate anticoagulant therapy after implantation of LVAD.

Geranylgeranyltransferase Cwg2-Rho4/Rho5 module is implicated in the Pmk1 MAP kinase-mediated cell wall integrity pathway in fission yeast.

Pmk1, a fission yeast homologue of mammalian ERK MAPK, regulates cell wall integrity, cytokinesis, RNA granule formation and ion homeostasis. Our screen for vic (viable in the presence of immunosuppressant and chloride ion) mutants identified regulators of the Pmk1 MAPK signaling, including Cpp1 and Rho2, based on the genetic interaction between calcineurin and Pmk1 MAPK. Here, we identified the vic2-1 mutants carrying a mis-sense mutation in the cwg2(+) gene encoding a beta subunit of geranylgeranyltransferase I (GGTase I), which participates in the post-translational C-terminal modification of several small GTPases, allowing their targeting to the membrane. Analysis of the vic2-1/cwg2-v2 mutant strain showed that the localization of Rho1, Rho4, Rho5 and Cdc42, both at the plasma and vacuolar membranes, was impaired in the vic2-1/cwg2-v2 mutant cells. In addition, Rho4 and Rho5 deletion cells exhibited the vic phenotype and cell wall integrity defects, shared phenotypes among the components of the Pmk1 MAPK pathway. Consistently, the phosphorylation of Pmk1 MAPK on heat shock was decreased in the cwg2-v2 mutants, and rho4- and rho5-null cells. Moreover, Rho4 and Rho5 associate with Pck1/Pck2. Possible roles of Cwg2, Rho4 and Rho5 in the Pmk1 signaling will be discussed.

Chemical genomics approach to identify genes associated with sensitivity to rapamycin in the fission yeast Schizosaccharomyces pombe.

Rapamycin and its derivatives have now emerged as an attractive therapeutic strategy with both immunosuppressant and antitumor properties. In addition, rapamycin has been proposed as a calorie restriction mimetic to extend the life span of various organisms. The fission yeast Schizosaccharomyces pombe (S. pombe) serves as a valuable genetic model system to study the mechanism(s) of drug action as well as to determine genetic contexts associated with drug sensitivity or resistance. Here, we identified genes that when deleted modulate the rapamycin-sensitive strains in S. pombe. We carried out a chemical genomics screen for rapamycin-sensitive mutants using the genome-deletion library which covers 95.3% of all nonessential fission yeast genes and confirmed 59 genes to be rapamycin sensitive. Gene Ontology (GO) enrichment analysis showed that strains sensitive to rapamycin are highly enriched in processes regulating tRNA modification and mitochondria as well as other ontologies, including cellular metabolic process, chromatin organization, cell cycle, signaling, translation, transport and other cellular processes. Analysis also showed that components of the Elongator complex are overrepresented in the sensitive strains. Here, the data obtained will provide valuable information for speculation on the actions of rapamycin as well as on TORC signaling, thereby presenting a strategy to enhance sensitivity to rapamycin.

Impact of the CYP3A5*1 Allele on the Pharmacokinetics of Tacrolimus in Japanese Heart Transplant Patients.

BACKGROUND AND OBJECTIVE: Tacrolimus, a major immunosuppressant used after transplantation, is associated with large interindividual variation involving genetic polymorphisms in metabolic processes. A common variant of the cytochrome P450 (CYP) 3A5 gene, CYP3A5*3, affects blood concentrations of tacrolimus. However, tacrolimus pharmacokinetics at the early stage of transplantation have not been adequately studied in heart transplantation. We retrospectively examined the impact of the CYP3A5 genotype on tacrolimus pharmacokinetics at the early stage of heart transplantation. METHODS: The tacrolimus pharmacokinetic profile was obtained from 65 patients during the first 5 weeks after heart transplantation. Differences in the patients' characteristics and tacrolimus pharmacokinetic parameters between the CYP3A5 expresser (*1/*1 or *1/*3 genotypes) and non-expresser (*3/*3 genotype) groups were assessed by the Chi-square test, Student's t test, or Mann-Whitney U test. RESULTS: The CYP3A5 *1/*1, *1/*3, and *3/*3 genotypes were detected in 5, 22, and 38 patients, respectively. All patients started clotrimazole therapy approximately 1 week after starting tacrolimus. Apparent clearance and dose/weight to reach the target trough concentration (C0) were significantly higher in the expresser group than in the non-expresser group (0.32 vs. 0.19 L/h/kg, p = 0.0003; 0.052 vs. 0.034 mg/kg/day, p = 0.0002); there were no significant differences in the area under the concentration-time curve from 0 to 12 h (AUC0-12) and concentrations at any sampling time point between the two groups. CONCLUSION: Similar concentration-time curves for tacrolimus were obtained in the expresser and non-expresser groups by dose adjustment based on therapeutic drug monitoring. These results demonstrate the importance of the CYP3A5 genotype in tacrolimus dose optimization based on therapeutic drug monitoring after heart transplantation.