Pharmacokinetic comparisons of two different varenicline formulations in humans: Varenicline tartrate versus varenicline oxalate
.

BACKGROUND AND OBJECTIVE: Varenicline is an effective drug for smoking cessation. The aim of the present study was to compare the pharmacokinetics and safety profiles of two different varenicline formulations (varenicline tartrate (reference) and varenicline oxalate (test)), each containing 1 mg varenicline base in humans. MATERIALS AND METHODS: A randomized, open-label, two-sequence, two-period, single-dose crossover study with a 2-week washout period was conducted with 30 healthy male participants. Blood samples for the pharmacokinetic analysis of varenicline were collected up to 96 hours following the administration of each drug. Pharmacokinetic parameters were also calculated, including the peak plasma concentration (Cmax), area under the plasma concentration-time curve (AUC) from time zero to the time of the last measurable concentration (AUClast) as well as AUC from time zero to infinity (AUCinf). ANOVA for pharmacokinetic equivalence was assessed using log-transformed Cmax and AUC values, and the geometric mean ratios (GMRs) and their 90% confidence intervals (CIs) were assessed as well. The safety profiles were also assessed. RESULTS: 27 participants completed the study. No significant differences were found for any pharmacokinetic parameters of varenicline between the two formulations. The observed average values of Cmax, AUClast, and AUCinf were 4.46 ng/mL, 97.68 ng×h/mL, and 101.60 ng×h/mL for reference and 4.54 ng/mL, 97.10 ng×h/mL, and 100.97 ng×h/mL for test, respectively. The GMRs and 90% CIs for Cmax, AUClast, and AUCinf were 1.0106 (0.9626 - 1.0610), 0.9904 (0.9540 - 1.0282), and 0.9885 (0.9517 - 1.0268), respectively. No clinically relevant changes were observed in the physical, biochemical, hematologic, electrocardiographic, or urinalysis findings during the study, and no serious adverse events were found. CONCLUSION: The results of the present study reveal that varenicline oxalate and varenicline tartrate have similar pharmacokinetic characteristics as varenicline, and that these two formulations exhibit pharmacokinetic equivalence to meet the regulatory criteria. Both varenicline formulations were generally well tolerated.

Model-based assessment of the benefits and risks of recombinant tissue plasminogen activator treatment in acute ischaemic stroke.

AIMS: Recombinant tissue plasminogen activator (rt-PA) is the only first-line agent approved by the US Food and Drug Administration to treat acute ischaemic stroke. However, it often causes the serious adverse event (AE) of haemorrhagic transformation. The present study developed a pharmacometric model for the rt-PA treatment effect and AE and, using the developed model, proposed a benefit-to-risk ratio assessment scheme as a supportive tool to optimize treatment outcome. METHODS: The data from 336 acute ischaemic stroke patients were used. The treatment effect was assessed based on an improvement in National Institutes of Health Stroke Scale (NIHSS) scores, which were described using an item response theory (IRT)-based disease progression model. Treatment failure and AE probabilities, and their occurrence times, were described by incidence and time-to-event models. Using the developed model, benefit-to-risk ratios were simulated under various scenarios using the global benefit-to-risk trade-off ratio (GBR). RESULTS: High initial NIHSS score and middle cerebral artery (MCA) stroke were risk factors for treatment failure, where the failure rate with MCA stroke was 2.87-fold higher than with non-MCA stroke. The haemorrhagic transformation time was associated with longitudinal changes in NIHSS scores. The benefit-to-risk ratio simulated was highest in minor stroke severity, with GBR >1 in all scenarios, and the ratio with non-MCA stroke was 2-3 fold higher than with MCA stroke. CONCLUSIONS: The study demonstrated the feasibility of applying an IRT model to describing the time course of the rt-PA treatment effect and AE. Benefit-to-risk ratio analyses showed that the treatment was optimal in non-MCA stroke with minor stroke severity.

Efficacy and Safety of a Fixed-Dose Combination Therapy of Tamsulosin and Tadalafil for Patients With Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Randomized, Double-Blinded, Active-Controlled Trial.

BACKGROUND: Phosphodiesterase type 5 inhibitors and α-adrenergic blocking agents (α-blockers) are widely used for the treatment of erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). AIMS: To assess the efficacy and safety of fixed-dose combinations (FDCs) of tamsulosin and tadalafil compared with tadalafil monotherapy in patients with comorbid BPH-associated LUTS and ED. METHODS: A randomized, double-blinded, active-controlled trial was conducted of 510 men with BPH-associated LUTS and ED. Patients were treated with FDCs of tamsulosin 0.4 mg plus tadalafil 5 mg (FDC 0.4/5 mg), tamsulosin 0.2 mg plus tadalafil 5 mg (FDC 0.2/5 mg), or tadalafil 5 mg for a 12-week treatment period. For a subsequent 12-week extension period, the patients were administered FDC 0.4/5 mg. OUTCOMES: The primary outcomes were changes from baseline in total International Prostate Symptom Score (IPSS) and International Index of Erectile Function erectile function domain (IIEF-EF) score at week 12 to prove superiority and non-inferiority of FDCs compared with tadalafil 5 mg. The safety assessments were adverse reactions, laboratory test results, and vital signs at week 24. RESULTS: The mean changes in total IPSS and IIEF-EF scores were -9.46 and 9.17 for FDC 0.4/5 mg and -8.14 and 9.49 for tadalafil 5 mg, respectively, which indicated superiority in LUTS improvement (P = .0320) and non-inferiority in ED treatment with FDC 0.4/5 mg compared with tadalafil 5 mg. However, the results from FDC 0.2/5 mg failed to demonstrate superiority in LUTS improvement. No clinically significant adverse events regarding the investigational products were observed during the 24-week period. CLINICAL IMPLICATIONS: The FDC 0.4/5 mg is the first combined formulation of an α-blocker and a phosphodiesterase type 5 inhibitor that offers benefits in patient compliance and as add-on therapy in patients with comorbid BPH-associated LUTS and ED. STRENGTHS AND LIMITATIONS: The study clearly demonstrated the advantage of FDC 0.4/5 mg. The main advantage of FDC 0.4/5 mg was the enhanced efficacy on BPH-associated LUTS comorbidity with ED, the lower incidence of side effects, and the simplification and convenience of therapy, which led to better overall patient compliance. However, the lack of a tamsulosin monotherapy control group was a limitation of this study. CONCLUSION: The FDC 0.4/5 mg therapy was safe, well tolerated, and efficacious, indicating that combination therapy could provide clinical benefits for patients with BPH-associated LUTS complaints and ameliorate the comorbidity of ED. Kim SW, Park NC, Lee SW, et al. Efficacy and Safety of a Fixed-Dose Combination Therapy of Tamsulosin and Tadalafil for Patients With Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Randomized, Double-Blinded, Active-Controlled Trial. J Sex Med 2017;14:1018-1027.

Pore dilatation increases the bicarbonate permeability of CFTR, ANO1 and glycine receptor anion channels.

KEY POINTS: Cellular stimuli can modulate the ion selectivity of some anion channels, such as CFTR, ANO1 and the glycine receptor (GlyR), by changing pore size. Ion selectivity of CFTR, ANO1 and GlyR is critically affected by the electric permittivity and diameter of the channel pore. Pore size change affects the energy barriers of ion dehydration as well as that of size-exclusion of anion permeation. Pore dilatation increases the bicarbonate permeability (P HC O3/ Cl ) of CFTR, ANO1 and GlyR. Dynamic change in P HC O3/ Cl may mediate many physiological and pathological processes. ABSTRACT: Chloride (Cl(-) ) and bicarbonate (HCO3 (-) ) are two major anions and their permeation through anion channels plays essential roles in our body. However, the mechanism of ion selection by the anion channels is largely unknown. Here, we provide evidence that pore dilatation increases the bicarbonate permeability (P HC O3/ Cl ) of anion channels by reducing energy barriers of size-exclusion and ion dehydration of HCO3 (-) permeation. Molecular, physiological and computational analyses of major anion channels, such as cystic fibrosis transmembrane conductance regulator (CFTR), anoctamin-1(ANO1/TMEM16A) and the glycine receptor (GlyR), revealed that the ion selectivity of anion channels is basically determined by the electric permittivity and diameter of the pore. Importantly, cellular stimuli dynamically modulate the anion selectivity of CFTR and ANO1 by changing the pore size. In addition, pore dilatation by a mutation in the pore-lining region alters the anion selectivity of GlyR. Changes in pore size affected not only the energy barriers of size exclusion but that of ion dehydration by altering the electric permittivity of water-filled cavity in the pore. The dynamic increase in P HC O3/ Cl by pore dilatation may have many physiological and pathophysiological implications ranging from epithelial HCO3 (-) secretion to neuronal excitation.

Pharmacokinetics of a nanocrystal-containing megestrol acetate formulation: a single-dose, randomized, open-label, 2-part, 2-period crossover study in healthy Korean subjects.

UNLABELLED: OBJECTIVE: The conventional suspension of megestrol acetate contains micronized megestrol acetate, which was recently discovered to have a disadvantage of decreasing bioavailability when taken in a fasting state. Since megestrol acetate is taken to increase appetite, this property becomes a discouraging factor. To improve upon this, an advanced formulation was developed using a nanocrystal drug-delivery system. This study was conducted to compare the safety and pharmacokinetic characteristics between the conventional formulation of megestrol acetate and a generic version of the advanced formulation containing nanocrystals. METHODS: This was a randomized, open-label, 2-period, 2-treatment, crossover, single-dose, 2-part study (part 1 fasting and part 2 fed), conducted in healthy males aged between 20 and 50 years with weight within ± 20% of ideal body weight having no congenital abnormalities or chronic diseases. Different subjects were used in part 1 and part 2, but subjects received a single dose of the reference and test drugs separated by a 14-day washout period. Blood sampling was performed up to 120 hours after dosing using a pre-specified sampling time scheme. Primary pharmacokinetic parameters were C_max and AUC_last of the test and reference formulations of megestrol acetate. Bioequivalence evaluation was based on the standard criterion of 80 - 125% for the 90% confidence interval of geometric mean ratios of test to reference drugs calculated for the pharmacokinetic parameters. To monitor adverse events, both subject interviews and physical examinations were done on a regular time basis. RESULTS: 80 subjects (n = 40 each part) were enrolled, and 79 completed the study. The 90% CIs of the geometric mean ratios of C_max and AUC_last were 4.4625 - 5.6018 and 1.3602 - 1.6418, respectively, for part 1, and 0.9793 - 1.1327 and 0.7721 - 0.8431, respectively, for part 2. No significant difference was discovered in the incidence of adverse events (AEs) when test and reference treated groups were compared. CONCLUSIONS: Our findings suggest that the test formulation of megestrol-acetate-containing nanocrystals is better absorbed and has higher bioavailability compared to the reference formulation in a fasting state. This should allow for a lower dose and better patient compliance.

ClinicalTrials.gov identifier: NCT02446353.

Pharmacokinetics of a telmisartan/rosuvastatin fixed-dose combination: a single-dose, randomized, open-label, 2-period crossover study in healthy Korean subjects.

OBJECTIVE: As hypertension and dyslipidemia are frequent comorbidities, antihypertensive drugs and lipid-lowering agents are often prescribed together for their treatment. Telmisartan and rosuvastatin are widely used together to treat hypertension and dyslipidemia. A combination formulation of these two drugs would improve patient compliance due to ease of dosing. The purpose of this study was to assess bioequivalence of single-dose administration of a newly-developed fixed-dose combination (FDC) tablet containing telmisartan/rosuvastatin 80/20 mg (test treatment) and coadministration of a telmisartan 80-mg tablet and a rosuvastatin 20-mg tablet (reference treatment) in healthy Korean male volunteers. METHODS: This was a single-dose, randomized, open-label, 2-period crossover study enrolling healthy males aged 20 - 50 years with BMI between 18.5 and 25 kg/m2. Each subject received a single dose of the reference and test treatments with a 14-day washout period. Blood sampling was performed at prespecified intervals for up to 72 hours after dosing. Primary pharmacokinetic parameters were Cmax, AUClast, and AUC0-∞ of telmisartan, rosuvastatin, and N-desmethyl rosuvastatin. Bioequivalence was assessed by determining whether the 90% confidence intervals (CIs) of the geometric mean ratios (test treatment/reference treatment) of these parameters were within the standard range of 80% to 125%. Adverse events were monitored via regular interviews with the subjects and by physical examinations. RESULTS: 60 subjects were enrolled and 55 completed the study. The 90% CIs of the geometric mean ratios of Cmax, AUClast, and AUC00-∞ were 0.9262-1.1498, 0.9294-1.0313, and 0.9312-1.0320 for telmisartan, 0.9041-1.0428, 0.9262-1.0085, and 0.9307-1.0094 for rosuvastatin, and 0.8718-1.0022, 0.8901-0.9904, and 0.8872-0.9767 for N-desmethyl rosuvastatin, respectively. There was no statistical difference in the incidence of adverse events (AEs) (all of which were mild or moderate) between the reference and test treatments. CONCLUSIONS: Our findings suggest that the telmisartan/rosuvastatin FDC is bioequivalent to coadministration of separate tablets, and both treatments were safe and well tolerated. Administration of this FDC tablet is expected to improve patient compliance.

Population pharmacokinetic analysis of diurnal and seasonal variations of plasma concentrations of cilostazol in healthy volunteers.

BACKGROUND: The background of this study was (1) to examine factors influencing cilostazol pharmacokinetics by developing a population model incorporating diurnal variation and other covariate effects and (2) to assess the feasibility of applying the developed model to determine the optimal dosing times. METHODS: Data obtained from a cilostazol pharmacokinetic study consisting of 2 clinical trials (a single twice-a-day (BID) dosing trial in winter and a multiple BID dosing trial in summer) conducted in healthy Korean subjects were used for model building. A basic model was built, followed by a diurnal variation model, and then a final model was built incorporating covariates, including a seasonal difference. The optimal morning and evening dosing times were determined from simulations. RESULTS: Diurnal variation in cilostazol pharmacokinetics was explained by the morning absorption rate constant being faster than in the evening, yielding values of 0.278 versus 0.234/h in summer, when 24- and 12-hour circadian rhythms were included in the model. The seasonal variation was explained by a 26.9% and a 31.8% decrease in the absorption rate constant and clearance, respectively, in winter compared with summer. Based on twice-a-day (BID) dosing, dosing times of 9 AM and 5 PM in summer and 10 AM and 7 PM in winter were expected to produce the smallest peak-to-peak fluctuations in cilostazol concentration, possibly minimizing unwanted effects of the drug. CONCLUSIONS: This study demonstrated the intraday and interseasonal time-varying nature of cilostazol pharmacokinetics using a population modeling approach and developed a strategy for optimizing dosing times. It is suggested that these methods can be similarly applied to analyses and controls of other drugs that exhibit characteristics of time-varying pharmacokinetics.

Mechanistic Model for Blood Pressure and Heart Rate Changes Produced by Telmisartan in Human Beings.

Telmisartan, an angiotensin receptor blocker (ARB), is indicated for the treatment of essential hypertension. This study aimed to develop a mechanistic model of telmisartan drug effect in human beings using non-invasive markers. Data were acquired from a previous study where telmisartan 80 mg was given once daily for 6 days. Systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR) were measured before dosing for days 1-5 and serially after the last dose. Mean arterial pressure (MAP) and pulse pressure (PP) were calculated from SBP and DBP. Relationships between MAP, PP, HR and total peripheral resistance (TPR) were developed. Circadian variation was incorporated into PP and HR, and TPR was assumed to adjust itself in response to changes in PP and HR based on baroreflex mechanism. Drug effects were then described as lowering the set point of MAP through TPR with a physiological feedback effect stimulating HR and PP. Drug concentrations were described by a two-compartment disposition model with first-order absorption and lag time, and first-order elimination. Circadian variation was described by cosine functions, having periods of 12 and 24 hr. A log-linear model was used to describe drug effect, with estimated drug effect parameter of 0.051/hr. Estimated fractional turnover rate of PP, HR and TPR was 11.2 hr. The model successfully described the time courses of these cardiovascular variables. This work demonstrated the feasibility of using non-invasive cardiovascular measurements to derive a mechanistic model for telmisartan in human beings. The model may be suitable for other ARBs.

Pharmacokinetics comparison of solifenacin tartrate and solifenacin succinate: a randomized, open-label, single-dose, 2-way crossover study in healthy male volunteers.

Solifenacin is a muscarinic antagonist indicated for the treatment of overactive bladder with symptoms. Solifenacin tartrate is a newly developed salt formulation of solifenacin. This study compared the pharmacokinetic and safety properties after single-dose administration of solifenacin tartrate (test formulation) and solifenacin succinate (reference formulation) in healthy male volunteers. A total of 36 subjects were enrolled in this randomized, open-label, single-dose, two-way crossover study. During each treatment period, subjects received the test formulation or reference formulation. Plasma samples were collected at pre-dose and at 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 24, 48 and 72 hours post-dose. Safety was assessed by adverse events, physical examinations, laboratory assessments, 12-lead electrocardiograms, and vital signs. Thirty-three subjects completed the study and were included in the pharmacokinetic analysis. The mean (standard deviation) values of AUClast for the test and reference formulations were 486.98 (138.47) and 469.07 (128.29) h·ng/mL, respectively. The mean (standard deviation) values of Cmax for the test and reference formulations were 14.66 (3.85) and 14.10 (3.37) ng/mL, respectively. The 90% confidence intervals for AUClast and Cmax were 0.9702 to 1.1097 and 0.9779 to 1.0993, respectively. All adverse events were mild or moderate, and there were no serious adverse events. The pharmacokinetic properties of solifenacin tartrate were similar to those of solifenacin succinate and met the acceptance criteria for bioequivalence. Both formulations were safe, and no significant difference was observed in the safety assessments of the formulations.

Pharmacokinetic interactions and tolerability of rosuvastatin and ezetimibe: an open-label, randomized, multiple-dose, crossover study in healthy male volunteers.

PURPOSE: Rosuvastatin is a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor that effectively reduces low-density lipoprotein cholesterol levels. However, statin monotherapy does not always achieve acceptable low-density lipoprotein cholesterol levels in patients with severe hypercholesterolemia. Ezetimibe, a selective cholesterol-absorption inhibitor, is approved for use as a monotherapy or combination therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors for patients with hypercholesterolemia. The aim of this study was to examine the pharmacokinetics (PKs) of drug interactions between rosuvastatin and ezetimibe, and the tolerability of combined administration in healthy Korean male volunteers. SUBJECTS AND METHODS: Healthy subjects (n=24) were randomly allocated to 3 treatment groups: rosuvastatin (20 mg) alone, ezetimibe (10 mg) alone, and rosuvastatin (20 mg) plus ezetimibe (10 mg). The drugs were taken once every 24 hours over a period of 10 days. Blood samples were collected to analyze steady-state PKs. RESULTS: All adverse events observed during the study were mild, and the frequency was no higher for combined administration than for mono administration. For rosuvastatin, the steady-state mean ratios (90% CI) of the combined over the single dose were 1.076 (1.019-1.136) for AUCτ,ss and 1.099 (1.003-1.204) for concentration at steady-state, respectively. In the case of free and total ezetimibe, the steady-state ratios of AUCτ,ss and concentration at steady-state were 1.131 (1.051-1.218) and 1.182 (1.038-1.346), and 1.055 (0.969-1.148) and 0.996 (0.873-1.135), respectively. CONCLUSION: Combined administration of rosuvastatin and ezetimibe was well tolerated. No clinically significant PK interactions between rosuvastatin and ezetimibe were observed when the 2 drugs were administered concomitantly.

Quantitative Assessment of Food Effect on the Pharmacokinetics of Nano-Crystallized Megestrol Acetate.

Megestrol acetate, an appetite stimulant with low bioavailability, shows increased bioavailability when taken together with food. However, the pharmacokinetic characteristics of megestrol acetate and its relation with food are not well understood. This study aimed to investigate the food effect on the pharmacokinetics (PK) of the recently developed nano-crystallized megestrol acetate (NCMA), using a model-based approach. Data were obtained from an NCMA PK study consisting of a single dose in fasting (39 individuals) and fed conditions (40 individuals). Plasma concentrations were measured up to 120 hr after dosing. With the incorporation of body-weight via allometry, NONMEM 7.3 was used to develop a PK model, which was then used to simulate an optimal fasting dose yielding an area under concentration (AUC) and maximum concentration (Cmax ) of NCMA close to those obtained with the fed dose. NCMA concentrations were best characterized by a two-compartment model with first-order absorption linked to a recycling compartment to account for the multiple concentration peaks observed. Food increased bioavailability 2.2 times and decreased the absorption rate constant 0.58 times. Recycling event times were estimated to be 3.56, 7.99 and 24.0 hr. The optimal fast dose was 2.0 times higher than the fed dose, and the resulting difference in drug exposure between the fasting and fed dose was 7.5%. This work suggests that the PK model developed can be applied to an optimal dosage regimen design for NCMA treatment.

Pharmacokinetic characteristics of fluticasone, salmeterol and tiotropium after concurrent inhalation.

Chronic obstructive pulmonary disease (COPD) is a type of progressive, obstructive lung disease characterized by long-term poor airflow. The symptoms of COPD may be relieved and its progression delayed by fluticasone (FTS), salmeterol (SM), and tiotropium (TTP). The aim of this study is to investigate pharmacokinetic (PK) characteristics of inhaled FTS, SM, and TTP after co-administration. An open-label, single-arm, three-period, simple ascending dose study was conducted in 10 healthy male subjects. A single dose of FTS/SM (250/50 µg) and TTP (18 µg) were concomitantly inhaled in period 1, and the dose of each drug was escalated to two- and three-fold in periods 2 and 3, respectively, with a 2-week washout between periods. Activated charcoal was co-administered before and after inhalation to block gastrointestinal absorption. Blood samples for PK analysis were collected up to 24 hours. PK parameters were obtained by non-compartmental analysis. FTS, SM, and TTP rapidly reached maximum plasma concentration after inhalation (0.08-3.00 h, 0.03-0.10 h and 0.03-0.10 h, respectively) and were eliminated with mean half-lives of 9.29-10.44 h, 6.09-12.39 h and 0.25-47.42 h, respectively. PK assessment of the lowest dose of TTP was limited due to relatively low systemic exposure compared to the lower limit of quantification. In conclusion, PK characteristics of FTS, SM, and TTP by pulmonary absorption were evaluated after concurrent inhalation. FTS and SM showed dose-proportional PK profiles between 250-750 µg and 50-150 µg, respectively, while TTP presented dose-proportionality in the early phase exposure between 18-54 µg.

Development of a pharmacokinetic interaction model for co-administration of simvastatin and amlodipine.

A model for drug interaction between amlodipine and simvastatin was developed using concentration data obtained from a multiple-dose study consisting of single- and co-administration of amlodipine and simvastatin conducted in healthy Koreans. Amlodipine concentrations were assumed to influence the clearance of simvastatin and simvastatin acid, which as well as the oral bioavailability was allowed to vary depending on genetic polymorphisms of metabolic enzymes. Covariate effects on drug concentrations were also considered. The developed model yielded a 46% increase in simvastatin bioavailability and a 13% decrease in simvastatin clearance when amlodipine 10 mg was co-administered. When CYP3A4/5 polymorphisms were assessed by a mixture model, extensive metabolizers yielded a decrease in simvastatin bioavailability of 81% and a decrease in simvastatin clearance by 4.6 times as compared to poor metabolizers. Sixty percent of the usual dose was the optimal simvastatin dose that can minimize the interaction with amlodipine 10 mg. Age and weight had significant effects on amlodipine concentrations. In conclusion, this study has quantitatively described the pharmacokinetic interaction between simvastatin and amlodipine using a modeling approach. Given that the two drugs are often prescribed together, the developed model is expected to contribute to more efficient and safer drug treatment when they are co-administered.

Pharmacokinetic interaction between rosuvastatin and olmesartan: a randomized, open-label, 3-period, multiple-dose crossover study in healthy Korean male subjects.

PURPOSE: Rosuvastatin has been widely used in combination with olmesartan for the treatment of dyslipidemia accompanied by hypertension. With no information currently available on the interaction between the 2 drugs, a pharmacokinetic study was conducted to investigate the influence of rosuvastatin on olmesartan and vice versa when the 2 drugs were coadministered. The purpose of this study was to investigate the pharmacokinetic profile of coadministration of the rosuvastatin 20-mg tablet and the olmesartan 40-mg tablet and the associated drug-drug interaction in healthy Korean male volunteers. METHODS: This was a randomized, open-label, 3-period, multiple-dose crossover study. Eligible subjects were aged 20 to 50 years and within 20% of their ideal body weight. After being randomly assigned to 6 groups of equal number, subjects received each of the following 3 formulations once a day for 7 consecutive days with an 8-day washout period between the formulations: rosuvastatin 20-mg tablet, olmesartan 40-mg tablet, and coadministration of the rosuvastatin 20-mg tablet and the olmesartan 40-mg tablet. Blood samples were collected up to 72 hours after dosing, and pharmacokinetic parameters were determined for rosuvastatin, its active metabolite (N-desmethyl rosuvastatin), and olmesartan. Adverse events were evaluated based on subject interviews and physical examinations. FINDINGS: Among the 36 enrolled subjects, 34 completed the study (mean [range] age, 28.6 [23-49] y; mean [range] weight, 66.4 [52.2-78.7] kg). The 90% CIs of the geometric mean ratios for the primary pharmacokinetic parameters for the coadministration of the 2 drugs to the mono-administration of each drug were 85.14% to 96.08% for AUCτ and 81.41% to 97.48% for Css,max for rosuvastatin, and 77.55% to 89.48% for AUCτ and 75.62% to 90.12% for Css,max for N-desmethyl rosuvastatin; those values were 95.61% to 102.57% for AUCτ and 91.73% to 102.98% for Css,max for olmesartan. Dizziness was the most frequently noted adverse drug reaction, occurring in 1 subject receiving mono-administration of rosuvastatin, 1 subject receiving mono-administration of olmesartan, and 4 subjects receiving coadministration of rosuvastatin and olmesartan. All the adverse events were expected, and there was no significant difference in the incidence between the 2 formulations. IMPLICATIONS: This study suggests that rosuvastatin and olmesartan did not significantly influence each other's pharmacokinetics when coadministered. Although the pharmacokinetics of N-desmethyl rosuvastatin were influenced by olmesartan, such interactions were considered clinically insignificant. All 3 formulations were well tolerated, and no serious adverse events or drug reactions were noted.

Pharmacokinetic interaction between rosuvastatin and metformin in healthy Korean male volunteers: a randomized, open-label, 3-period, crossover, multiple-dose study.

PURPOSE: Rosuvastatin is indicated for hypercholesterolemia or dyslipidemia and metformin mainly for type 2 diabetes. These 2 drugs are frequently prescribed in combination due to the high comorbidity of the 2 diseases. However the nature of pharmacokinetic interaction between the 2 drugs has not been previously investigated. The purpose of our study was to investigate the pharmacokinetic interaction between rosuvastatin and metformin in healthy Korean male volunteers. METHODS: This was a randomized, open-label, 6-sequence, 3-period, crossover, multiple-dose study. Eligible subjects, aged 20 to 50 years and within 20% of the ideal body weight, received 1 of the following 3 treatments for each period once daily for 5 consecutive days with a 10-day washout period between the treatments: monoadministration of rosuvastatin 10 mg tablet, monoadministration of metformin 750 mg tablet, and coadministration of rosuvastatin 10 mg tablet with metformin 750 mg tablet. Blood samples were collected up to 72 hours after the last dose and pharmacokinetic parameters for rosuvastatin and metformin were compared between combination and monotherapy. Adverse events were investigated and evaluated based on subject interviews and physical examinations. FINDINGS: Among the 36 enrolled subjects, 31 completed the study. The coadministration of rosuvastatin with metformin produced a significant pharmacokinetic interaction in rosuvastatin Css,max, with the 90% CI for the geometric mean ratio (coadministration:monoadministration) being 110.27% to 136.39% (P = 0.0029), whereas no significant interaction was observed in rosuvastatin AUCtau, yielding the 90% CI of 104.41% to 118.95%. When metformin was coadministered with rosuvastatin, no significant pharmacokinetic interaction was observed for Css,max and AUCtau of metformin, yielding the 90% CIs of the geometric mean ratio for coadministration to monoadministration as 87.38% to 102.54% and 86.70% to 99.08%, respectively. Overall, 19 mild and 1 moderate adverse events occurred in 12 subjects, with no significant differences in the incidence among the 3 treatments. IMPLICATIONS: Although the Css,max of rosuvastatin was significantly influenced by coadministration with metformin, the degree of interaction seen was considered clinically insignificant, with no significant interaction observed in the other pharmacokinetic measures between the 2 drugs. These results imply that drug effects of rosuvastatin and metformin will also not be significantly influenced by coadministration of the 2 drugs. All treatments were well tolerated and no serious adverse events occurred. ClinicalTrials.gov identifier: NCT01526317.

Pharmacokinetic interaction between rosuvastatin and telmisartan in healthy Korean male volunteers: a randomized, open-label, two-period, crossover, multiple-dose study.

PURPOSE: Rosuvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, and telmisartan, an angiotensin receptor blocker, are commonly prescribed in combination for the treatment of dyslipidemia accompanied by hypertension. However, the nature of the pharmacokinetic interaction between the 2 drugs is not clearly understood. The goal of the present study was to investigate the pharmacokinetic drug-drug interaction between rosuvastatin and telmisartan in a healthy Korean population. METHODS: This was a randomized, 2-part, open-label, 2-period, crossover, multiple-dose study, with each part composed of different subjects between the ages of 20 and 55 years. In part 1, each subject received rosuvastatin 20 mg with and without telmisartan 80 mg once daily for 6 consecutive days. In part 2, each subject received telmisartan 80 mg with and without rosuvastatin 20 mg once daily for 6 consecutive days. In both parts, there was a 16-day washout period between mono- and coadministration. Blood samples were collected up to 72 hours after the last dose. Adverse events (AEs) were evaluated through interviews and physical examinations. FINDINGS: In part 1, the 90% CIs of the geometric mean ratios for the primary pharmacokinetic parameters for coadministration of the 2 drugs to monoadministration of each drug were 1.0736-1.2932 for AUCτ and 1.7442-2.3229 for Cmax,ss for rosuvastatin and 0.9942-1.1594 for AUCτ and 1.3593-1.7169 for Cmax,ss for N-desmethyl rosuvastatin, whereas in part 2, the CIs were 1.0834-1.2672 for AUCτ and 1.1534-1.5803 for Cmax,ss for telmisartan. The most frequently noted AE was cough in part 1, which occurred in 2 subjects receiving the combination therapy, and oropharyngeal pain in part 2, which occurred in 3 subjects receiving the combination therapy. All reported AEs were mild or moderate, and there was no significant difference in incidence between the treatments. IMPLICATIONS: These findings demonstrated that rosuvastatin and telmisartan mutually affected each other's pharmacokinetics, suggesting a possibility of drug-drug interaction. However, based on dose-response characteristics of the 2 drugs and previous results from other interaction studies, the degree of drug interaction observed in this study was not regarded as clinically significant. All treatments were well tolerated, with no serious AEs observed. ClinicalTrials.gov identifier: NCT01992601.

Pharmacokinetics of rosuvastatin/olmesartan fixed-dose combination: a single-dose, randomized, open-label, 2-period crossover study in healthy Korean subjects.

BACKGROUND: Rosuvastatin, a lipid-lowering agent, has been widely used with olmesartan, a long-acting angiotensin II receptor blocker, indicated for the treatment of dyslipidemia accompanied by hypertension. A fixed-dose combination (FDC) tablet of these 2 drugs was recently developed to enhance the dosing convenience and to increase patient compliance while yielding pharmacokinetic profiles comparable to coadministration of each drug as individual tablets. OBJECTIVE: The goal of present study was to compare the pharmacokinetic profiles of single-dose administration of an FDC tablet containing rosuvastatin/olmesartan 20/40 mg (test formulation) with coadministration of a rosuvastatin 20-mg tablet and a olmesartan 40-mg tablet (reference formulation) in healthy Korean male volunteers, for the purpose of determining bioequivalence. METHODS: This single-dose, randomized, open-label, 2-period crossover study enrolled subjects aged 20 to 50 years and within 20% of ideal body weight. Each subject received a single dose of the test and reference formulations orally in a fasted state, with a 7-day washout period between the administrations. Blood samples were collected up to 72 hours after dosing, and pharmacokinetic parameters were determined for rosuvastatin, its active metabolite (N-desmethyl rosuvastatin), and olmesartan. Bioequivalence was concluded if the 90% CIs of the geometric mean ratios for the primary pharmacokinetic parameters were within the predetermined range of 80% to 125%. Adverse events (AEs) were evaluated based on subject interviews and physical examinations. RESULTS: Among the 58 enrolled subjects, 54 completed the study. The 90% CIs of the geometric mean ratios of the primary pharmacokinetic parameters were as follows: rosuvastatin: AUC(last), 85.60% to 97.40% and C(max), 83.16% to 98.21%; N-desmethyl rosuvastatin: AUC(last), 82.08% to 93.45% and C(max), 79.23% to 93.41%; and olmesartan: AUC(last), 97.69% to 105.69% and C(max), 100.35% to 109.42%. The most frequently noted AE was headache, occurring in 3 and 6 patients with the test and reference formulations, respectively. All of the AEs were expected, and there was no significant difference in the prevalences of AEs between the 2 formulations. CONCLUSIONS: The pharmacokinetic properties of the newly developed FDC tablet of rosuvastatin/olmesartan 20/40 mg suggest that it is bioequivalent to co-administration of each drug as individual tablets in these healthy Korean male subjects. The two formulations were well tolerated, with no serious AEs observed. ClinicalTrials.gov identifier: NCT01823900.

Pharmacokinetic comparison of an orally disintegrating film formulation with a film-coated tablet formulation of sildenafil in healthy Korean subjects: a randomized, open-label, single-dose, 2-period crossover study.

BACKGROUND: An orally disintegrating film (ODF) formulation of sildenafil was recently developed in Korea. This formulation is expected to enhance dosing convenience and increase patient compliance while yielding pharmacokinetics comparable to those of the conventional film-coated tablet (FCT) formulation. OBJECTIVE: The goal of this study was to compare the pharmacokinetic profiles of a newly developed ODF formulation with those of a FCT formulation of sildenafil in healthy Korean male volunteers. METHODS: This was a randomized, open-label, single-dose, 2-period crossover study conducted in 2 parts. Eligible subjects were between the ages of 20 and 50 years and within 20% of their ideal weight; subjects were equally divided into parts 1 and 2. Each subject received a single dose of the ODF and FCT formulations of sildenafil orally in a fasted state (part 1, 50 mg; part 2, 100 mg), with a 7-day washout period between the formulations. Blood samples were collected up to 24 hours postdosing. Pharmacokinetic parameters were determined for sildenafil and its active metabolite (N-desmethyl sildenafil). Adverse events (AEs) were evaluated based on subject interviews and physical examinations. RESULTS: Among the 120 enrolled subjects (60 subjects for each part), 110 completed the study (part 1, n = 53; part 2, n = 57). In both parts, all the primary pharmacokinetic parameters were included in the range for assumed bioequivalence in sildenafil, yielding 90% CI ratios of 91.07% to 120.67% for AUC0-last and 86.68% to 122.93% for Cmax in part 1, and 101.68% to 114.78% for AUC0-last and 93.76% to 109.76% for Cmax in part 2. In part 1, headache was the most frequently noted AE, occurring in 3 subjects with both the test and the reference formulations. All other AEs occurred in <3 subjects. In part 2, nasal congestion was the most frequently observed AE (7 with the test formulation and 1 with the reference formulation), followed by abnormal vision (4 with the test formulation and 4 with the reference formulation), headache (4 with the test formulation and 4 with the reference formulation), and rhinorrhea (5 with the test formulation). All other AEs occurred in <3 subjects. CONCLUSIONS: The study findings suggest that the pharmacokinetics of the ODF formulation of sildenafil do not differ significantly from those of the conventional FCT formulation (50 and 100 mg) in these healthy Korean male subjects. The 2 formulations were well tolerated in both parts of the study, with no serious AEs observed. ClinicalTrials.gov identifier: NCT01769638.

Pharmacokinetic comparison of 2 fixed-dose combination tablets of amlodipine and valsartan in healthy male Korean volunteers: a randomized, open-label, 2-period, single-dose, crossover study.

BACKGROUND: Amlodipine and valsartan have different mechanisms of action, and it is known that the combination therapy with the 2 drugs increases treatment effects compared with the monotherapy with each drug. A fixed-dose combination (FDC) drug is a formulation including fixed amounts of active drug ingredients combined in a single dosage form that is expected to improve medication compliance. OBJECTIVE: The goal of this study was to compare the pharmacokinetic profiles of single administration of a newly developed FDC tablet containing amlodipine orotate 10 mg and valsartan 160 mg (test formulation) with the conventional FDC tablet of amlodipine besylate 10 mg and valsartan 160 mg (reference formulation) in healthy male Korean volunteers. METHODS: This was a randomized, open-label, single-dose, 2-way crossover study. Eligible subjects were between the ages of 20 and 50 years and within 20% of their ideal weight. Each subject received a single dose of the reference and the test formulations, with a 14-day washout period between formulations. Blood samples were collected up to 144 hours after the dose, and pharmacokinetic parameters were determined for amlodipine and valsartan. Adverse events were evaluated based on subject interviews and physical examinations. RESULTS: Forty-eight of the 50 enrolled subjects completed the study. For both amlodipine and valsartan, the primary pharmacokinetic parameters were included in the range for assumed bioequivalence, yielding 90% CI ratios of 0.9277 to 0.9903 for AUC(0-last) and 0.9357 to 1.0068 for C(max) in amlodipine, and 0.9784 to 1.1817 for AUC(0-last) and 0.9738 to 1.2145 for C(max) in valsartan. Dizziness was the most frequently noted adverse event, occurring in 4 subjects with the test formulation, followed by oropharyngeal pain occurring in 1 subject with the test formulation and 3 subjects with the reference formulation. All other adverse events occurred in <3 subjects. CONCLUSIONS: These findings suggest that the pharmacokinetics of the newly developed FDC tablet of amlodipine and valsartan did not differ significantly from the conventional FDC tablet in these healthy Korean male subjects. Both formulations were well tolerated, with no serious adverse events observed. ClinicalTrials.gov identifier: NCT01823913.