Exercise prevented the lansoprazole-induced reduction of anti-osteoporotic efficacy of alendronate in androgen deficiency rats.

Clinical studies indicate that proton pump inhibitors (PPIs), used long-term in elderly patients, increase the risk of osteoporotic fractures, and decrease the anti-fracture efficacy of alendronate. The aim of the present study was to examine the effect of physical exercise on the anti-osteoporotic efficacy of alendronate administered concurrently with lansoprazole, a PPI, in male rats with androgen deficiency induced by orchidectomy. Male Wistar rats at 3 months of age were divided into: sham-operated control rats, orchidectomized (ORX) control rats, ORX rats receiving alendronate, ORX rats receiving alendronate and lansoprazole, ORX rats receiving alendronate and subjected to exercise, and ORX rats receiving alendronate and lansoprazole and subjected to exercise. The orchidectomy or sham-operation was performed 7-8 days before the start of drug administration. The rats were subjected to the exercise on the treadmill 1 hour/day for 7 weeks (6 days a week). Alendronate sodium (3 mg/kg p.o.) and lansoprazole (4 mg/kg p.o.) were administered once daily for 7 weeks (6 days a week). Mechanical properties of the tibial metaphysis and femoral neck were assessed. Bone turnover markers, histomorphometric parameters, bone mass and mass of bone mineral were also studied. Lansoprazole weakened the anti-osteoporotic efficacy of alendronate. The exercise increased the alendronate effect. Similar changes were observed in the rats treated with lansoprazole and alendronate, subjected to exercise; no deleterious effects of lansoprazole were observed. In conclusion, the exercise prevented the lansoprazole-induced reduction the anti-osteoporotic efficacy of alendronate in orchidectomized rats.