Targeting outpatients of our hospital, we administered alendronate to 143 cases from January to December 2002, and risedronate to 64 cases from August 2002 to February 2003. As a result of these experiments, we noticed that the occurrence rate of hazardous findings in the digestive tract in each period was 18.1% and 7.8% respectively. The results of large scale experiments indicated no significant difference between them. As the occurrence rate ranged from 20% to 30%, the occurrence rate of hazardous findings in the digestive tract due to arendronate at our hospital was more or less reasonable, but that by risedronate seemed extraordinarily low. This is apparently due to our staff's awareness that risedronate was marketed lately, so the occurrence rate of hazardous findings in the digestive tract is low, resulting in the psychological effect of instructing patiens to take this drug.
