Background/Aims: Tegoprazan, a novel potassium-competitive acid blocker, is expected to overcome the limitations of proton pump inhibitors and effectively control nocturnal acid breakthrough. To evaluate the pharmacodynamics of tegoprazan versus dexlansoprazole regarding nocturnal acid breakthrough in healthy subjects. Methods: In a randomized, open-label, single-dose, balanced incomplete block crossover study, 24 healthy male volunteers were enrolled and randomized to receive oral tegoprazan (50, 100, or 200 mg) or dexlansoprazole (60 mg) during each of two administration periods, separated by a 7- to 10-day washout period. Blood samples were collected for pharmacokinetic parameter analysis; gastric monitoring was performed for pharmacodynamic parameter evaluation. Results: All 24 subjects completed the study. Average maximum plasma concentration, area under the plasma concentration–time curve, and mean time with gastric pH >4 and pH >6 for tegoprazan demonstrated dose-dependent incremental increases. All the tegoprazan groups reached mean pH ≥4 within 2 hours, whereas the dexlansoprazole group required 7 hours after drug administration. Based on pharmacodynamic parameters up to 12 hours after evening dosing, 50, 100, and 200 mg of tegoprazan presented a stronger acid-suppressive effect than 60 mg of dexlansoprazole. Moreover, the dexlansoprazole group presented a comparable acid-suppressive effect with the tegoprazan groups 12 hours after dosing. Conclusions All the tegoprazan groups demonstrated a significantly faster onset of gastric pH increase and longer holding times above pH >4 and pH >6 up to 12 hours after evening dosing than the dexlansoprazole group.

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.
Administration, Oral ; Chromatography, Liquid ; Erectile Dysfunction ; Humans ; Imidazoles ; Male ; Piperazines ; Sulfones ; Tandem Mass Spectrometry ; Triazines