Oral esomeprazole vs. intravenous pantoprazole: a comparison of the effect on intragastric pH in healthy subjects D. ARMSTRONG*, D. BAIR*, C. JAMES*, L. TANSER  , S. ESCOBEDO  & K. NEVIN   *Division of Gastroenterology, McMaster University & Hamilton Health Sciences, Hamilton, ON, Canada; and  AstraZeneca Canada Inc., Mississauga, ON, Canada Accepted for publication 10 July 2003 SUMMARY Background: Intravenous (IV) proton-pump inhibitor therapy is used in patients who cannot take oral medications or require greater acid suppression. Oral esomeprazole produces greater acid suppression than oral pantoprazole; however, no comparative data exist for oral esomeprazole and IV pantoprazole. Aim: To compare acid suppression (time with pH > 3.0, 4.0, 5.0 and 6.0) produced by standard doses of oral esomeprazole and IV pantoprazole in healthy subjects. Methods: A randomized, two-way crossover study in 30 subjects receiving oral esomeprazole (40 mg o.d.) or IV pantoprazole (40 mg o.d.) for 5 days followed by a 2-week washout period before the second 5-day drug administration period using the crossover drug regimen. Results: Oral esomeprazole produced greater acid sup- pression than IV pantoprazole on day 1 [pH > 3.0 (56.9%, 35.8%; P < 0.001), pH > 4.0 (43.4%, 25.0%; P < 0.001) and pH > 5.0 (28.7%, 15.6%; P < 0.001)] and on day 5 [pH > 3.0 (70.4%, 45.9%; P < 0.001), pH > 4.0 (59.2%, 33.9%; P < 0.001), pH > 5.0 (45.5%, 23.9%; P < 0.001) and pH > 6.0 (19.6%, 12.6%; P ¼ 0.045)]. The adverse event profiles indica- ted both treatments to be safe and well tolerated. Conclusions: In healthy subjects, esomeprazole, 40 mg o.d. dispersed in water, produces greater acid suppres- sion than pantoprazole 40 mg IV o.d. after 1 and 5 days of medication. INTRODUCTION Oral proton-pump inhibitor therapy produces a high degree of acid suppression and is very effective for the management of acid-related disorders. High-dose, intra- venous proton-pump inhibitor therapy given as a bolus followed by a continuous infusion is recommended for patients with upper gastrointestinal haemorrhage; intravenous proton-pump inhibitor therapy may also be required for patients who are unable to take oral medication. 1, 2 Currently, pantoprazole is the only IV proton-pump inhibitor commercially available in North America, and its use in the hospital environment has led to increasing concerns about appropriate use of IV acid suppressants and the potential for increased costs. 3, 4 With this in mind, oral proton-pump inhibitors might be prescribed more readily for hospital inpatients if it could be shown clearly that they are comparable to IV proton- pump inhibitors. Esomeprazole, the S-isomer of omeprazole, has an improved pharmacokinetic profile leading to greater acid suppression than that produced by omeprazole, pantoprazole, lansoprazole and rabeprazole. 5 In clinical studies, the greater acid suppression produced by esomeprazole has translated into higher healing rates and more effective symptom relief when compared to lansoprazole and omeprazole in gastro-oesophageal Correspondence to: Dr D. Armstrong, Division of Gastroenterology, HSC- 4W8, McMaster University Medical Centre, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada. E-mail: armstro@mcmaster.ca Aliment Pharmacol Ther 2003; 18: 705–711. doi: 10.1046/j.1365-2036.2003.01743.x Ó 2003 Blackwell Publishing Ltd 705