Evaluation of effects of altered gastric pH on absorption of dapsone in healthy volunteers.

A prospective, randomized, crossover study was performed with seven healthy volunteers to address the effect of increased gastric pH on dapsone absorption. Subjects were randomized to receive a single 100-mg dose of dapsone or a single 100-mg dose of dapsone in addition to 30 ml of a high potency antacid 1 h before dapsone administration and hourly thereafter for a total of 10 doses. Dapsone concentrations in serum were measured periodically for 48 h. No statistical differences between the two regimens were noted when mean dapsone maximal initial concentrations, times to peak, and areas under the curve were compared. These data suggest that an increase in gastric pH has little or no effect on the absorption of dapsone in healthy subjects.