The study involved 515 healthy, postmenopausal woman, with no risk factors for peptic ulcers, in 10 sites around the USA and Canada.
"Biphosphonates differ in their potential to cause damage to the gastroesophageal mucosa."
For a two-week treatment period, 255 were randomized to risedronate 5mg/d, and the remaining 260 received alendronate 10mg/d. These are the doses currently approved for osteoporosis treatment.
The subjects were monitored by endoscopy at days 0, 8 and 15. The study compared gastric ulcer incidence, and the esophageal, gastric and duodenal mucosal damage scores.
Gastric ulcers after 14d:
Gastric ulcers (>3 mm) were observed in 9 (4.1%) subjects in the risedronate group, compared with 30 (13.2%) subjects in the alendronate group - a significant difference.
Gastric mucosal scores for the risedronate group were significantly lower than those for the alendronate group at days 8 and 15.
Esophageal and duodenal mucosal scores were similar in the two treatment groups.