On-Demand Proton Pump Inhibitory Treatment in Overweight/Obese Patients with Gastroesophageal Reflux Disease: Are There Pharmacodynamic Arguments for Using Higher Doses?

Background: Increased body mass index (BMI) is associated with a higher risk of gastroesophageal reflux disease (GORD). Aim: To investigate whether overweight/obesity affects proton pump inhibitor pharmacodynamics when used in a single dose in patients with GORD. Methods: Post hoc analyses by patient BMI were performed on data from two single-center, double-blind, single-dose, crossover studies comparing the pharmacodynamics of rabeprazole 20 mg and pantoprazole 40 mg in GORD patients with a history of nocturnal heartburn. The primary endpoint was the mean percentage of time with intragastric pH >4 between lean and overweight/obese patients (BMI <25 and ≥25). Results: 24 h baseline intragastric pH values were not different between BMI groups. The pharmacodynamic effects of both proton pump inhibitors were not significantly different between BMI groups, and no evidence was found for an interaction between BMI and treatment. As compared with pantoprazole, rabeprazole showed a significantly greater effect on the antisecretory response for both BMI groups. Conclusions: Overweight/obesity in GORD patients does not appear to affect the antisecretory efficacy of a single dose of rabeprazole and pantoprazole. These data do not support adapting the dosage of rabeprazole and pantoprazole according to BMI in GORD patients when administered as an on-demand therapy schedule.