Translational and Clinical Pharmacology: Note from the new Editor-in-Chief

No abstract available.

Prediction and visualization of CYP2D6 genotype-based phenotype using clustering algorithms

This study focused on the role of cytochrome P450 2D6 (CYP2D6) genotypes to predict phenotypes in the metabolism of dextromethorphan. CYP2D6 genotypes and metabolic ratios (MRs) of dextromethorphan were determined in 201 Koreans. Unsupervised clustering algorithms, hierarchical and k-means clustering analysis, and color visualizations of CYP2D6 activity were performed on a subset of 130 subjects. A total of 23 different genotypes were identified, five of which were observed in one subject. Phenotype classifications were based on the means, medians, and standard deviations of the log MR values for each genotype. Color visualization was used to display the mean and median of each genotype as different color intensities. Cutoff values were determined using receiver operating characteristic curves from the k-means analysis, and the data were validated in the remaining subset of 71 subjects. Using the two highest silhouette values, the selected numbers of clusters were three (the best) and four. The findings from the two clustering algorithms were similar to those of other studies, classifying *5/*5 as a lowest activity group and genotypes containing duplicated alleles (i.e., CYP2D6*1/*2N) as a highest activity group. The validation of the k-means clustering results with data from the 71 subjects revealed relatively high concordance rates: 92.8% and 73.9% in three and four clusters, respectively. Additionally, color visualization allowed for rapid interpretation of results. Although the clustering approach to predict CYP2D6 phenotype from CYP2D6 genotype is not fully complete, it provides general information about the genotype to phenotype relationship, including rare genotypes with only one subject.

History of clinical pharmacology in Korea

No abstract available.

Pharmacokinetics of T-614 after Single Oral Administration in Healthy Korean Volunteers

BACKGROUND: Iguratimod is a new type of disease modifying anti-rheumatic drug, which reduced the production of inflammatory cytokines. The purpose of this study was to evaluate pharmacokinetic characteristics and safety profiles of iguratimod after a single oral administration in healthy Korean volunteers. METHODS: A randomized, double-blind, placebo-controlled, parallel group, single oral dose study was conducted in 24 healthy male volunteers. Three groups of eight subjects each received 25 mg, 50 mg, or 100 mg dosage, respectively. Two subjects in each dose group were administered matching placebo. Plasma concentrations of iguratimod were measured till 72 hours after drug administration. Tolerability was evaluated by monitoring adverse events, clinical laboratory tests, and 12-lead electrocardiograms. RESULTS: The mean area under the concentration-time curve from 0 to 72 hours (AUClast) were 11.9, 25.2, and 51.8 mg x h/L and the maximum plasma concentration (Cmax) were 1.15, 2.33, and 4.78 mg/L in 25, 50 and 100 mg dose groups, respectively. All doses of iguratimod were well tolerated without serious adverse events or clinically meaningful changes. CONCLUSION: Cmax and AUClast values of iguratimod proportionally increased with incremental dose. Iguratimod was generally safe and well tolerated.

A Randomized, Placebo Controlled, Double Blind, Parallel Group, Multiple Dosing, Dose Escalation Clinical Study to Evaluate Pharmacokinetics/Pharmacodynamics and Tolerability of Zofenopril in Healthy Korean Subjects

BACKGROUND: Zofenopril is a new Angiotensin Converting Enzyme (ACE) inhibitor for the treatment of the patients with hypertension and congestive heart failure. This study aimed to evaluate the pharmacokinetics (PKs)/pharmacodynamics (PDs) and tolerability of zofenopril in healthy Korean subjects. METHODS: A randomized, double blind, placebo-controlled, multiple dosing parallel group study with two dosage groups (zofenopril 30 mg or 60 mg) was conducted in healthy Korean male subjects. Each dosage group consisted of 10 subjects and they were randomly assigned to receive zofenopril or placebo with a ratio of 4:1. PK characteristics of zofenopril and its active metabolite, zofenoprilat, were evaluated after single or multiple dosing. Serum ACE activities and blood pressures were measured for PD evaluation. Adverse events, clinical laboratory tests, electrocardiograms, vital signs and physical examinations were performed for tolerability evaluation. RESULTS: The PK characteristics of zofenopril and zofenoprilat after single dose and multiple doses were similar to one another. The metabolic ratio of zofenoprilat to zofenopril after single dose and multiple doses were 12.4 and 14.9, respectively, in the 30 mg dosage group, and were 6.8 and 6.6, respectively, in the 60 mg dosage group. Complete serum ACE activity inhibition was observed within 1 hour in both doses but it was maintained longer in the 60 mg dosage group compared to the 30 mg dosage group. There were no clinically significant abnormalities in tolerability evaluations. CONCLUSION: The PK/PD characteristics of zofenopril and zofenoprilat after single or multiple administrations were explored. Zofenopril was well tolerated after multiple administrations in healthy Korean subjects.

Tolerability and Pharmacokinetics Following a Single Dose of Vardenafil in Healthy Korean Volunteers

BACKGROUND: Vardenafil is a phosphodiesterase type 5 inhibitor, used in erectile dysfunction. This study aimed to evaluate the pharmacokinetics and tolerability of vardenafil following a single oral administration in healthy male subjects. METHODS: A randomized, double-blind, placebo-controlled, single dosing, dose-escalation study was conducted in 30 healthy subjects. A single oral dose of vardenafil or placebo was given to 10 subjects (8 active + 2 placebo) in each dose group of 5, 10 and 20 mg. Serial blood and urine samples were obtained up to 48 hours for pharmacokinetic analysis. Vardenafil and its metabolite were detected by high performance liquid chromatography tandem mass spectrometry assay. RESULTS: A total of 45 adverse events (AE) were reported in 22 subjects, including 5 AEs from placebo treatment, and all the AEs were mild, except one case of moderate nasal stuffiness. Vardenafil was absorbed after a single oral dose, with the tmax of 0.5-1.0 hours. The Cmax and AUClast were 10.21 +/- 3.68 ug/L(mean +/- SD) and 18.08 +/- 7.44 ugxh/L in 5 mg dose group, 19.79 +/- 12.13 ug/L and 38.61 +/- 21.04 ugxh/L in 10 mg dose group and 53.16 +/- 37.01 ug/L and 110.05 +/- 69.65 ugxh/L in 20 mg dose group. Dose-linearity on AUClast and Cmax of vardenafil were observed in three dose groups. In all dose groups, the fraction excreted in urine was less than 1%. CONCLUSION: The vardenafil was tolerable over a single dose range of 5 - 20 mg. The pharmacokinetics of vardenfil after a single oral dose was explored and linear pharmacokinetic characteristics were observed over the dose range of 5 - 20 mg in healthy subjects.

Results of 2012 KoNECT Certification Program of the Human Resource Project

BACKGROUND: In recent years, clinical trials have considerably increased and relevant education programs to clinical trials have been developed and implemented since 2008 in Korea. To enhance the quality as well as global competitiveness of clinical trial professionals (CTPs), a certification program of the human resource is needed. Accordingly, in Korea the first and the second certification examinations were implemented in February and October 2012, respectively. In this paper, introduction of the certification program of the human resource is described, and results of the certification examinations and questionnaire survey are presented. METHODS: Data including the examination results and questionnaire survey was collected by cooperative officials in Korea National Enterprise for Clinical Trials. Applicants who were selected eligible for examination by the steering committee were asked to complete questionnaires provided with the test papers on the day of the certification examination. RESULTS: In the first certification examination, a total of 221 eligible participants completed the examination. 99.5 % of the participants responded the questionnaire survey. In the second examination, a total of 223 applicants participated. The examination consisted of 50 multiple-choice questions with cut-off score of 70 per cent score.176 & 194 CTPs passed the first & second examinations respectively. CONCLUSION: This paper that described the results of the two certification tests and questionnaire surveys might be helpful in establishment and activation of the certification program in the future. Quality improvement of CTPs and international competitiveness of clinical trial in Korea can be anticipated by the certification program.

Results of 2012 KoNECT Certification Program of the Human Resource Project

BACKGROUND: In recent years, clinical trials have considerably increased and relevant education programs to clinical trials have been developed and implemented since 2008 in Korea. To enhance the quality as well as global competitiveness of clinical trial professionals (CTPs), a certification program of the human resource is needed. Accordingly, in Korea the first and the second certification examinations were implemented in February and October 2012, respectively. In this paper, introduction of the certification program of the human resource is described, and results of the certification examinations and questionnaire survey are presented. METHODS: Data including the examination results and questionnaire survey was collected by cooperative officials in Korea National Enterprise for Clinical Trials. Applicants who were selected eligible for examination by the steering committee were asked to complete questionnaires provided with the test papers on the day of the certification examination. RESULTS: In the first certification examination, a total of 221 eligible participants completed the examination. 99.5 % of the participants responded the questionnaire survey. In the second examination, a total of 223 applicants participated. The examination consisted of 50 multiple-choice questions with cut-off score of 70 per cent score.176 & 194 CTPs passed the first & second examinations respectively. CONCLUSION: This paper that described the results of the two certification tests and questionnaire surveys might be helpful in establishment and activation of the certification program in the future. Quality improvement of CTPs and international competitiveness of clinical trial in Korea can be anticipated by the certification program.

Influence of Simvastatin on Pharmacokinetics/Pharmacodynamics of Aspirin after Oral Co-administration in Healthy Volunteers

BACKGROUND: Both aspirin and simvastatin are prescribed as treatments or prevention of cardiovascular diseases. The aim of this study was to investigate the influence of simvastatin on pharmacokinetics and pharmacodynamics of aspirin after oral co-administration in healthy subjects. METHODS: Subjects were orally administered aspirin 100 mg for 7 days followed by co-administration of aspirin 100 mg and simvastatin 40 mg for 7 days once daily. A series of blood samples were collected before and till 24hours after drug administration on Day 1 (single-dose of aspirin), Day 7 (multiple-dose of aspirin) and Day 14 (multiple-dose of aspirin and simvastatin). The effects of simvastatin on pharmacokinetics of acetylsalicylic acid and salicylic acid were assessed with the 90 % confidence intervals (CIs) of thegeometric mean ratios (GMRs) of Day 14 over Day 7 for maximum plasma concentration (Cmax) and the area under the concentration-time curve (AUC0-24). Pharmacodynamics was assessed with maximal changes of platelet aggregation from baseline. RESULTS: Twenty-fourhealthy men aged 20 to 36 years were enrolled and 23 of them completed the study. GMRs (90 % CIs) of Cmax and AUC0-24 for acetylsalicylic acid were 1.21 (1.04 - 1.42) and 1.28 (1.19 - 1.38), respectively. For salicylic acid, GMRs of Cmax and AUC0-24 were 0.96 (0.91 - 1.00) and 1.00 (0.97 - 1.04), respectively. Maximal changes of platelet aggregation on Day 7 and Day 14 from baseline were not significantly different (p=0.41); 87.5 +/- 8.8 % and 87.3 +/- 9.2 %, respectively. CONCLUSION: Coadministration of simvastatin slightly increased the systemic exposure of acetylsalicylic acid with no changes of systemic exposure of salicylic acid or inhibition of platelet aggregation.

Evaluation of Pharmacokinetics and Tolerability of Eplerenone after Multiple Oral Doses of 100 mg in Healthy Korean Volunteers

BACKGROUND: Eplerenone is a selective mineralocorticoid receptor antagonist which effectively blocks mineralocorticoid receptors in various tissues throughout the body. The addition of eplerenone to optimal medical therapy reduces morbidity and mortality among patients post acute myocardial infarction complicated by left ventricular dysfunction and heart failure. The aim of this study was to evaluate pharmacokinetic characteristics and tolerability after multiple oral administration of eplerenone 100 mg for 7 days in healthy Korean volunteers. METHODS: A double-blind, randomized, placebo-controlled, parallel study was conducted in 22 healthy Korean subjects. Healthy males and females between age of 20 and 55 years were enrolled. Each subject received 100 mg eplerenone (N=16) or placebo (N=6) for 7 days. Blood samples for pharmacokinetic parameter determination on day 7 were collected pre-dose and up to 36 hours after last drug administration. Adverse events were reported throughout the treatment period. RESULTS: The steady-state concentration of eplerenone reached after multiple administration of eplerenone 100 mg for 7 days. The mean eplerenone Cmax of 1620.1 ng/mL was obtained at 1.0 hour (range 0.5 to 2 hours). The mean AUC0-24h,ss at day 7 was 8763.6 ng/mL*h. The mean oral clearance and mean terminal half-life of eplerenone were 13.0 L/h and 3.4 hours. There were some drug-related mild adverse events after eplerenone administration, but all adverse events recovered without any treatment. CONCLUSION: In this study, the pharmacokinetic parameters after multiple oral doses of eplerenone 100 mg for 7 days were evaluated and eplerenone at these doses were well tolerated in healthy Korean subjects.

Pharmacokinetics and Tolerability Evaluation of Fudosteine after Oral Administration in Healthy Korean Volunteers

BACKGROUND: Fudosteine, (-)-(R)-2-amino-3-(3-hydroxypropylthio)propionic acid, is a cysteine derivative that was approved in Japan, as a new mucoactive agent. The aim of this study was to evaluate the tolerability and pharmacokinetics (PK) of fudosteine in healthy Korean subjects. METHODS: A randomized, open-label, parallel, escalating single-dose study was conducted in 16 healthy Korean male subjects. The subjects were allocated to single-dose groups of 400 or 800 mg. Serial blood samples for PK analysis were collected immediately prior and after dosing up to 24 hours, and plasma concentrations were determined by high performance liquid chromatography (HPLC). Safety profiles were evaluated by monitoring adverse events and clinical evaluations throughout the study. RESULTS: Median time to peak concentration (Tmax) of both dosing group were around 0.5 hours and half-life (t1/2) were around 3 hours. Mean peak concentration (Cmax) of 400 mg and 800 mg dosing group were 10.8 and 21.5 microg/mL and the mean area under the plasma concentration versus time curve from the dosing time to infinity (AUCinf) were 26.8 and 55.0 microg.h/mL, respectively. Mean dose-normalized Cmax were 0.0271 and 0.0269 microg/mL/mg (P=0.923), respectively and dose-normalized AUCinf were 0.0669 and 0.0688 microg.hr/mL/mg (P=0.093), respectively. Fudosteine was well tolerated without any serious adverse events or clinical laboratory abnormalities. CONCLUSION: This study showed that fudosteine has a linear PK property and is well tolerated within 800 mg in healthy Korean volunteers.

Pharmacokinetics and Tolerability Evaluation of Human Coagulation Recombinant Factor VIII (GreenGene(TM)) in Hemophilia A Patients

BACKGROUND: GreenGene(TM) (Green Cross Corp.) is a recombinant clotting factor VIII which is used for hemophilia A. This study aimed to investigate the pharmacokinetics and safety profiles of 25 IU/kg and 50 IU/kg of GreenGene(TM) in Korean hemophilia A patients. METHODS: A dose-block randomized, single-blind, active drug-controlled, single and multiple dose, parallel-group study was conducted with 16 hemophilia A patients (25 IU/kg: 50 IU/kg = 8:8). They received GreenGene(TM) or GreenMono(TM)(active control) intravenously on day 1 and every other day from day 4 to 10. FVIII:C (Factor VIII procoagulant activity) was measured to determine the pharmacokinetics (PK) at baseline and up to 48 hours for single and multiple administration. PK parameters were determined using noncompartmental methods. RESULTS: The maximum concentration (Cmax) and the area under the concentration-time curve (AUC0-48) of the GreenGene(TM) 25 IU/kg (mean +/- SD) were 59.00 +/- 19.26 % and 774.40 +/- 380.13 %.h respectively, while those of 50 IU/kg were 131.50 +/- 39.81 % and 1462.44 +/- 397.09 %.h after single administration. The Cmax and AUC0-48 in steady state of the GreenGene(TM) 25 IU/kg were 68.17 +/- 22.75 % and 863.30 +/- 334.40 %.h, while those of 50 IU/kg were 147.17 +/- 18.47 % and 1820.08 +/- 704.42 %.h. No serious adverse event was observed. CONCLUSION: The GreenGene(TM) to hemophilia A patients appeared to be well tolerated within range of 25-50 IU/kg. The PK parameters of factor VIII showed dose-independent manner with 25 IU/kg and 50 IU/kg dose ranges.

Asian society of gynecologic oncology workshop 2010 / 부인종양

This workshop was held on July 31-August 1, 2010 and was organized to promote the academic environment and to enhance the communication among Asian countries prior to the 2nd biennial meeting of Australian Society of Gynaecologic Oncologists (ASGO), which will be held on November 3-5, 2011. We summarized the whole contents presented at the workshop. Regarding cervical cancer screening in Asia, particularly in low resource settings, and an update on human papillomavirus (HPV) vaccination was described for prevention and radical surgery overview, fertility sparing and less radical surgery, nerve sparing radical surgery and primary chemoradiotherapy in locally advanced cervical cancer, were discussed for management. As to surgical techniques, nerve sparing radical hysterectomy, optimal staging in early ovarian cancer, laparoscopic radical hysterectomy, one-port surgery and robotic surgery were introduced. After three topics of endometrial cancer, laparoscopic surgery versus open surgery, role of lymphadenectomy and fertility sparing treatment, there was a special additional time for clinical trials in Asia. Finally, chemotherapy including neo-adjuvant chemotherapy, optimal surgical management, and the basis of targeted therapy in ovarian cancer were presented.

Therapeutic evaluation of sustained-releasing praziquantel (SRP) for clonorchiasis: Phase 1 and 2 clinical studies

Sustained-releasing praziquantel (SRP) tablet was designed for single dose treatment regimen of clonorchiasis. A previous pre-clinical study confirmed its sustained-releasing characteristics and a better cure rate than conventional praziquantel (PZQ). In this clinical study, the pharmacokinetics of this SRP tablet were investigated in human volunteers (phase 1; 12 volunteers), and its curative efficacy was examined in clonorchiasis patients (phase 2; 20 volunteers). In the phase 1 clinical study, blood concentrations of both tablets showed wide individual variation. The AUC(last) of SRP was 497.9+/-519.0 ng.hr/ml (mean+/-SD) and PZQ of 628.6+/-695.5 ng.hr/ml, and the AUC(inf) of SRP was 776.0+/-538.5 ng.hr/ml and of PZQ 658.6+/-709.9 ng.hr/ml. C(max) values of SRP and PZQ were 90.7+/-82.2 ng/ml and 214.9+/-251.9 ng/ml, and T(max) values were 3.42+/-1.43 hr and 1.96+/-1.23 hr, respectively. SRP tablets showed similar AUC values, but lower C(max) and longer T(max) values than PZQ. In the phase 2 study, SRP at 30 mg/kg (single dose) achieved a 60% cure rate and a 95.5% egg reduction rate. The cure rate of a single dose SRP was unsatisfactory compared with that of the conventional PZQ dose, but much better than that achieved by a single dose PZQ.

Removal of Amikacin in Patients Undergoing Continuous Venovenous Hemodiafiltration / 대한신장학회잡지

BACKGROUND: The purpose of this study was to investigate the pharmacokinetics of amikacin in critically ill patients undergoing continuous venovenous hemodiafiltration (CVVHDF). METHODS: Pharmacokinetic parameters in each of six renal failure patients were estimated by measurement of amikacin levels in serum and effluent samples. RESULTS: Average clearance of amikacin by CV VHDF was 28.5+/-4.6 mL/min (mean+/-standard deviation). The sieving coefficient was 0.62+/-0.2 in the hemodiafiltration system of Gambro AN69 membrane set. Volume of distribution of amikacin was estimated to be 0.47+/-0.08 L/kg lean body weight. The half-life of amikacin was significantly reduced by hemodiafiltration to 11.4+/-1.6 hr. 40% of the administered amikacin was removed by CVVHDF over the 24 hour study period. CONCLUSION: We recommend that 10 mg/kg of amikacin should be given i.v. every 48 hours to critically ill patients during CVVHDF. However, individualized approach based on therapeutic drug monitoring of plasma amikacin concentration is necessary for optimum amikacin therapy during CVVHDF due to the varying nature of critically ill patients.

At the Beginning of KMA Center for Drug Information & Evaluation

No abstract available.

Prescription Drug Product

No abstract available.

Current Status of the Institutional Review Boards in Korea: Constitution, Operation, and Policy for Protection of Human Research Participants

The institutional review board is crucial to ensure the scientific and ethical quality of human participant research. This paper analyzes a survey on the current constitution and operation of institutional review boards (IRBs) in Korea, conducted by the Korean Association of Institutional Review Boards in April 2002. Out of 74 IRBs, 63 responded to the survey (85.1% response rate). IRB membership has a male-to-female ratio of approximately 80:20, a predominance of male clinicians (60%) and an underrepresentation of community people unaffiliated to the institutions (less than 10%). Most IRBs (around 80%) confine the scope of their reviews to the clinical evaluation of drugs or devices, leaving the remaining areas of research involving human participants untouched. As their role is limited, the majority of IRBs do not operate actively: 72% of responding IRBs reviewed less than one protocol per month in 2001. Sixty two percent of institutions have never discussed the need for insuring research participants' risks or making indemnity arrangements. This survey reveals many shortcomings and points for improvement by the institutional support bodies, including the need to establish regular education programs for IRB members and investigators.

Pharmacokinetics of Antimycobacterial Drugs in Peritoneal Dialysis / 대한신장학회잡지

BACKGROUND: Tuberculosis is more prevalent in dialysis patients than in the general population, and more difficult to make a diagnosis, and often leads to death, Moreover, extra-caution is needed in prescribing anti-tuberculosis medications as dose modification is frequently needed in patients with renal insufficiency. Several pharmacokinetic studies have been performed for antimycobacterial regimens in patients with renal insufficiency, including under hemodialysis. However, the anti-mycobacterial regimens of patients on peritoneal dialysis have been made based on empirical methods because of few pharmacokinetic studies. METHODS: To elucidate the pharmacokinetic profiles of anti-mycobacterial regimens for peritoneal dialysis, we measured both plasma and peritosol concentrations of anti- tuberculous drugs including isoniazide, rifampin and pyrazinamide in 9 patients maintained on chronic ambulatory peritoneal dialysis(CAPD). RESULTS: After a conventional oral dose of anti-tuberculosis medication, their plasma concentrations were in the therapeutic range, but the peritosol concentration of rifampin was below the therapeutic range. CONCLUSION: No dose adjustments are required for isoniazid, rifampin and pyrazinamide for the treatment of systemic or peritoneal tuberculosis in CAPD patients. On the contrary, oral rifampin is not expected to be effective in the treatment of tuberculous peritonitis, because of its low peritosol concentration.

Does Albumin Preinfusion Potentiate Diuretic Action of Furosemide in Patients with Nephrotic Syndrome?

The aim of this cross-over study was to investigate whether albumin infusion before furosemide administration could potentiate the diuretic action of furosemide. Seven patients with nephrotic syndrome were given the following infusions in random order on two separate days: 1) a sham solution followed by 160 mg of furosemide, 2) 100 ml of 20% human albumin followed by 160 mg of furosemide. Urine and serum furosemide concentrations were measured by high-performance liquid chromatography. The increment of urine volume was greater in albumin preinfusion than in furosemide alone. However, the increments of sodium and chloride excretions between furosemide alone and albumin preinfusion were not different. No significant differences in the pharmacokinetic parameters between the two treatments were observed: area under the concentration-time curve (AUC: 12.7+/-2.2 vs 15.1+/-4.4 g/ml hr), total plasma clearance (253+/-41 vs 256+/-54 ml/min), volume of distribution (341+/-34 vs 494+/-153 ml/kg), elimination half life (4.0+/-1.1 vs 4.6+/-0.8 hr), and urine furosemide excretion of the administered amount (16.5+/-7.3 vs 7.5+/-1.6%). In conclusion, these data show that albumin preinfusion potentiated diuresis, but not natriuresis, of furosemide without any change in the pharmacokinetics of the agent in patients with nephrotic syndrome.