ABSTRACT
YH4808 is a novel potassium-competitive acid blocker developed for gastric acid-related disorders. Previous studies indicate its potential to improve symptoms of gastric acid-related disorders. The current study was aimed to find the optimal regimen of YH4808 for night time pH control. This study was performed in two parts. Each was a randomized, open-label, active-controlled, multiple-doses, two-treatment, two-period crossover study conducted in 20 healthy Korean volunteers. Subjects were randomly assigned to one of the four groups.The three groups received different dosage regimens of YH4808 (100 mg twice a day, 200 mg once a day, or 200 mg twice a day), and the fourth group received esomeprazole 40 mg twice a day. The pharmacokinetic parameters demonstrated that the systemic exposure of YH4808 increased in a dose-proportional manner. The difference in the proportion of time above pH 4 over 24 h from the baseline was the greatest in the group receiving YH4808 200 mg twice a day. The values of the area under the effect curve at night time (12 A.M.–7 A.M.) were higher in all YH4808 groups than in the esomeprazole group. However, the differences among the YH4808 groups were not statistically significant (p > 0.05). YH4808 exhibited potential for better pH control during the night in comparison to esomeprazole. The optimal regimen for night time pH control among all the YH4808 regimens was 200 mg twice a day.
ABSTRACT
BACKGROUND: Olmesartan medoxomil is an angiotensin II receptor blocker commonly used in hypertension. First objective of this study was to evaluate the bioequivalence of two olmesartan formulations, Olmesartan 20 mg and 40 mg tablet (Yuhan, Pharmaceutical Corp. Seoul, Korea) as test drugs and Olmetec(R) 20 mg and 40 mg tablet (Daewoong, Pharmaceutical Corp. Seoul, Korea) as reference drugs. Second objective of this study was to evaluate the dose-proportionality of two formulations. METHODS: Two studies (20 mg, 40 mg) were conducted as a randomized, open-label, 2-period, crossover design. Each subject received one 20 mg or 40 mg tablet of the reference or test formulation of olmesartan medoxomil in each study. Blood samples were obtained during the 48-hour period after the dose in each treatment period. Wash-out period was 1 week in each study. Concentrations of olmesartan medoxomil in plasma were analyzed using a liquid chromatography system with tandem mass-spectrometric detection (LC/MS/MS). The primary pharmacokinetic parameters were Cmax (maximum concentration) and AUCt (area under the concentration-time curve from time 0 to the last sampling time). RESULTS: A total number of 40 healthy male volunteers participated in the study and 37 volunteers completed both treatment periods in 20 mg trial. All 40 participants completed both treatment periods in 40 mg trial. The 90 % CIs for the geometric mean ratios of the pharmacokinetic parameters (test:reference drug) were 0.93 ~ 1.04 for AUCt and 0.97 ~ 1.08 for Cmax in 20 mg trial. The 90 CIs were 0.94 ~ 1.02 for AUCt and 1.00 ~ 1.11 for Cmax in 40 mg trial. All parameters of two studies satisfy the range of bioequivalence criterion. CONCLUSION: The obtained results indicated that pharmacokinetic exposure to Olmesartan 20 mg and 40 mg tablet was bioequivalent to that of Olmetec(R) 20 mg and 40 mg tablet, respectively.
Subject(s)
Humans , Male , Chromatography, Liquid , Cross-Over Studies , Hypertension , Imidazoles , Plasma , Receptors, Angiotensin , Tetrazoles , Therapeutic EquivalencyABSTRACT
BACKGROUND: The hemodynamic responses to endotracheal intubation are associated with sympathoadrenal activity. Polymorphisms in the beta1-adrenergic receptor (beta1AR) gene can alter the pathophysiology of specific diseases. The aim of this study is to investigate whether the Ser49Gly and Arg389Gly polymorphism of the beta1AR gene have different cardiovascular responses during endotracheal intubation under sevoflurane anesthesia. METHODS: Ninety-one healthy patients undergoing general anesthesia were enrolled. Patients underwent slow inhalation induction of anesthesia using sevoflurane in 100% oxygen. Vecuronium 0.15 mg/kg was given for muscle relaxation. Endotracheal intubation was performed by an anesthesiologist. The mean arterial pressure (MAP), heart rate (HR), and the corrected QT (QTc) interval were measured before induction, before laryngoscopy, and immediately after tracheal intubation. Genomic DNA was isolated from the patients' peripheral blood and then evaluated for the beta1AR-49 and beta1AR-389 genes using an allele-specific polymerase chain reaction method. RESULTS: No differences were found in the baseline values of MAP, HR, and the QTc interval among beta1AR-49 and beta1AR-389, respectively. In the case of beta1AR-49, the QTc interval change immediately after tracheal intubation was significantly greater in Ser/Ser genotypes than in Ser/Gly genotypes. No differences were observed immediately after tracheal intubation in MAP and HR for beta1AR-49 and beta1AR-389. CONCLUSIONS: We found an association between the Ser49 homozygote gene of beta1AR-49 polymorphism and increased QTc prolongation during endotracheal intubation with sevoflurane anesthesia. Thus, beta1AR-49 polymorphism may be useful in predicting the risk of arrhythmia during endotracheal intubation in patients with long QT syndrome.