Galmiche JP et al. (2005) A comparative study of the early effects of tenatoprazole 40 mg and esomeprazole 40 mg on intragastric pH in healthy volunteers. Aliment Pharmacol Ther 21: 575–582

Proton-pump inhibitors (PPIs) effectively prevent gastric-acid secretion and are used to control the symptoms of various acid-related gastrointestinal diseases. These compounds have a short plasma half-life, however, which limits the efficacy of a single dose. The novel PPI tenatoprazole, an imidazopyridine derivative, benefits from an extended plasma half-life and could negate the requirement for repeated dosing. Galmiche et al. have recently compared the effects of tenatoprazole with esomeprazole, a benzimidazole-derived PPI, on intragastric pH in healthy subjects.

The randomized, two-period crossover study recruited 24 healthy, male volunteers from a French academic institution. All subjects had no history of gastrointestinal disease and tested negative for Helicobacter pylori, HIV, and hepatitis B and C. Volunteers received either 40 mg tenatoprazole (T40) or esomeprazole 40 mg (E40) once daily for 2 consecutive days and, after a 2-week interim period, changed to the other regimen. All volunteers were hospitalized and intragastric pH was monitored every 5 s during the 48-hour dosing period. Nocturnal pH levels were significantly higher on both the first and second days in subjects receiving T40 when compared with those receiving E40, although this effect was not observed diurnally. T40 was also significantly more effective than E40 at reducing the duration of nocturnal acid breakthroughs. The time needed to reach a sustained increase in intragastric pH was, however, comparable for both drugs. The authors conclude that tenatoprazole is a potent acid suppressor and, in the first 48 h, exerts significantly better control over nocturnal intragastric pH than esomeprazole.