Hi, Risedronate sodium is a medicine called a type of bisphosphonate. It helps the bones stay as strong as possible. It prevents osteoporosis in where bones get weaker and more likely to break. It can help people who have Paget s disease of bone. Its side effects are nausea, vomiting, stomach pain, GIT upset, indigestion, bloating, headache, muscle pain, joint pain, a loose tooth, sore throat, red eye, heartburn, diarrhoea, bone pain, ear pain, blurred vision, light sensitivity, black or red coloured stool, constipation, allergic reactions etc. Take care. Hope I have answered your question. Let me know I can assist you further. Regards, Dr. Zubayer Alam, General And Family Physician