A randomized controlled trial to assess alendronate‐associated injury of the upper gastrointestinal tract

BACKGROUND: Aminobisphosphonates are recommended for postmenopausal osteoporosis but have been associated with injury to the upper gastrointestinal tract. AIM: To conduct a randomized controlled trial, to assess the endoscopic damage caused by alendronate and its effect on gastric mucosal prostaglandin synthesis. METHODS: Seventy-six healthy volunteers age 40-60 years, with normal baseline endoscopy were randomly assigned to treatment with: (A) ASA 650 mg q. d.s.; (B) alendronate 10 mg o.d.; or (C) placebo o.d. for 14 days. Mucosal injury scores on day 14 of treatment were reported by a blinded endoscopist. Gastric biopsies were analysed for prostaglandin E2 (PGE2) concentration by radioimmunoassay. RESULTS: Oesophageal injury did not differ among treatment groups. Gastric ulcers developed in five out of 26 subjects given ASA, two out of 25 given alendronate, and none of 25 given placebo. The mucosal damage scores for the alendronate group exceeded those for the placebo group in the gastric body but not at other sites. Injury scores for ASA exceeded those for placebo in the duodenum, antrum, body, and fundus. The mean change in log10[PGE2] (ng/mg protein) was - 0.07 for placebo, - 0.80 for ASA, and + 0.62 for alendronate (differences not significant). CONCLUSIONS: Alendronate is associated with injury and ulceration of the gastric mucosa. This effect was not associated with any significant change in gastric mucosal PGE2 levels.