The dramatic success of pharmacological acid suppression in healing peptic ulcers and managing patients with gastroesophageal reflux disease (GERD) has been reflected in the virtual abolition of elective surgery for ulcer disease, a reduction in nonsteroidal anti-inflammatory drug (NSAID)-associated gastropathy and the decision by most patients with reflux symptoms to continue medical therapy rather than undergo surgical intervention. However, a number of challenges remain in the management of acid-related disorders. These include management of patients with gastroesophageal symptoms who do not respond adequately to proton pump inhibitor (PPI) therapy, treatment of patients with nonvariceal upper gastrointestinal bleeding, prevention of stress-related mucosal bleeding, optimal treatment and prevention of NSAID-related gastrointestinal injury, and optimal combination of antisecretory and antibiotic therapy for the eradication of Helicobacter pylori infection. A number of new drugs are currently being investigated to provide a significant advance on current treatments. Some of them (namely potassium-competitive acid blockers (P-CABs) and CCK2-receptor antagonists) have already reached clinical testing while some others (like the antigastrin vaccine, H3-receptor ligands or gastrin-releasing peptide receptor antagonists) are still in preclinical development and need the proof of concept in human beings. Of the current approaches to reduce acid secretion, P-CABs and CCK2-receptor antagonists hold the greatest promise, with several compounds already in clinical trials. Although the quick onset of action of P-CABs (i.e. a full effect from the first dose) is appealing, the results of phase II studies with one such agent (namely AZD0865) did not show any advantages over esomeprazole. Thanks to their limited efficacy and the development of tolerance it is unlikely that CCK2 antagonists will be used alone as antisecretory compounds but, rather, their combination with PPIs will be attempted with the aim of reducing the long-term consequences of hypergastrinemia. While H2-receptor antagonists (especially soluble or over-the-counter formulations) will become the ‘antacids of the third millennium’ and will be particularly useful for on-demand symptom relief, clinicians will continue to rely on PPIs to control acid secretion in GERD and other acid-related diseases. In this connection, several new PPI formulations have been developed and two novel drugs (namely ilaprazole and tenatoprazole) are being studied in humans. The recently introduced immediate-release (IR) omeprazole formulation (currently available only in the USA) quickly increases intragastric pH and, given at bedtime, seems to achieve a better control of nocturnal acidity. IR formulations of other PPIs (including the investigational ones) will probably be available in the future and will enlarge our therapeutic armamentarium. Amongst the novel PPIs, tenatoprazole appears to be a true advance in the acid suppression therapy. Its long half-life (the longest among the available compounds) and longer duration of antisecretory action, with no difference between day and night, will allow the drug to go beyond the intrinsic limitations of currently available PPIs. Thanks to its favorable pharmacokinetics, the sodium salt of S-tenatoprazole is being developed and the preliminary results indicate that this drug has the potential to address unmet clinical needs. Although some decades have elapsed since the introduction of effective and safe antisecretory drugs in clinical practice and their use has stood the test of time, the ongoing research will further provide the clinician with more effective means of controlling acid secretion.

Keywords:
Gastric acid secretion, Acid inhibition, Antisecretory drugs, H2-receptor antagonists, Ebrotidine, Lafutidine, Proton pump inhibitors, Ilaprazole-Tenatoprazole, Potassium-competitive acid blockers, CCK2-receptor antagonists
This content is only available via PDF.
© 2006 S. Karger AG, Basel
2006
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.