Alendronate is a bisphosphonate medicine that alters bone formation and breakdown in the body. This can slow bone loss and may help prevent bone fractures. Alendronate is used to treat osteoporosis caused by menopause, steroid use, or gonadal failure. This medicine is for use when you have a high risk of bone fracture due to osteoporosis. Common side effects may include heartburn, upset stomach, stomach pain, nausea, diarrhea, constipation, bone pain, or muscle or joint pain. SN instructed pt to report if she experiences any of these s/sx. Pt voiced understanding.