Proceptin has been found to produce faster symptom relief and higher healing rates in a greater percentage of patients than either cimetidine or ranitidine, confirming the 'therapeutic gains' achievable with Proceptin over existing therapies. Omeprazole offers significant therapeutic gains in the treatment of acid related diseases: healing rates are high in duodenal ulcer, gastric ulcer and erosive reflux oesophagitis; acid production is controlled effectively in Zollinger-Ellison Syndrome, and symptom relief is prompt and sustained in all indications. Less clear-cut indications where benefit might be expected but where data are limited include: Prevention of stress ulceration, prevention of the acid aspiration syndrome.