Esomeprazole, the first proton pump inhibitor to be developed as an optical isomer, is quickly proving its worth. This innovative agent has been shown to be more successful than omeprazole in healing reflux oesophagitis, irrespective of the severity of the disease. It has also been shown to be effective for long-term on-demand treatment to control recurrent symptoms in patients with gastro-oesophageal reflux disease (GORD). Now, research spearheaded by Dr P Wahlqvist from AstraZeneca R&D Mölndal, Sweden, indicates that esomeprazole is cost effective compared with omeprazole, with the potential to generate substantial cost savings for health systems in Europe.