Equipotent inhibition of gastric acid secretion by equal doses of oral or intravenous pantoprazole.

BACKGROUND

Pantoprazole is a proton pump inhibitor characterized by a low potential to interact with the cytochrome P450 system, and linear pharmacokinetics. The recommended oral dose for treatment of acid-related diseases is 40 mg.

METHODS

Using a randomized, crossover study design we compared the ability of 40 mg oral and intravenous pantoprazole to elevate the intragastric pH in healthy volunteers (n = 20, 'per protocol'), during two treatment phases. The duration of each phase was 5 days. Pantoprazole 40 mg was administered once daily either as a tablet or as an intravenous injection. A 24 h pHmetry was used to record the intragastric pH on day 5 of each regimen; this was compared to the baseline curve obtained before each study period. The calculated 90% confidence intervals (90% CI) represent the mean difference in the intragastric pH, attained after intravenous or oral administration. The predefined equivalence range for the 90% CI was +/- 20% for the percentage time at which the gastric pH was at least pH 3 or 4 and +/- 1 unit for the median pH.

RESULTS

Pantoprazole was well tolerated during both treatment phases. The mean of the 24 h median pH was 3.3 and 3.1 for the intravenous and oral treatments, respectively; the corresponding differences were 0.2 (90% CI: - 0.03 to 0.44). For the mean percentage time at which the pH was 3 or above, the respective calculated values were 57% and 51%, with a difference between the two administration routes of only 5.7% (90% CI: 1.8 to 9.6). At an intragastric pH of 4 or above, the mean percentage time was 420% and 38% following intravenous and oral treatment, respectively, with a difference between the treatment routes of only 4.4% (90% CI: 0.6 to 8.3).

CONCLUSIONS

These results imply that the two formulations of pantoprazole can be assumed to be equipotent. Hence, the intravenous formulation of pantoprazole could be considered as an alternative route of administration.