Do acid suppressive drugs (pantoprazole and ranitidine) attenuate the protective effect of alendronate in estrogen-deficient osteoporotic rats?

Abstract Background Alendronate is a drug of choice in the treatment of postmenopausal osteoporosis. Acid suppressive drugs are recently used in combination with alendronate to protect against stomach ulceration and oesophagitis occurring as serious problems in patients under this treatment. Aim of the work To study the effect of pantoprazole and ranitidine on the anti-resorptive effect of alendronate in a rat model of osteoporosis. Material and methods 64 female Wister albino rats were included (8 rats/group). Treated groups were Ovariectomized bilaterally to induce osteoporosis. Rats were treated orally with alendronate (3 mg/kg/day), ranitidine (20 mg/kg/day), pantoprazole (3 mg/kg/day), combined alendronate and ranitidine or alendronate and pantoprazole for 4 weeks. Bone mineral density (BMD) was determined using dual-energy X-ray absorptiometry scan. Serum bone-specific alkaline phosphatase (BSALP), serum calcium, cortical thickness and histopathological examination were assessed. Results Induction of osteoporosis significantly elevated serum BSALP, decreased serum calcium, bone mineral density and cortical thickness and significantly increased the histopathological score. Ranitidine treatment resulted in insignificant changes in tested parameters. Pantoprazole given alone, significantly decreased serum calcium and increased serum BSALP. At the end of the experiment, alendronate significantly improved BSALP level, serum calcium, BMD, cortical thickness and histopathological score. This improvement was not affected by combining ranitidine with alendronate. Meanwhile, pantoprazole with alendronate caused a significant deterioration of tested parameters. Conclusion Ranitidine proved safer than pantoprazole for patients with high risk of osteoporosis and in alendronate-treated patients. Clinicians should carefully judge the indication of use of acid suppressing medications in osteoporotic patients.