Local irritation to the upper GI mucosa. Patient w/ active upper GI problems eg, dysphagia, oesophageal disease, gastritis, duodenitis or ulcers, or in cases of recent (during the last yr) severe GI disease eg, gastric ulcer, active GI bleeding or surgery in the upper GIT other than pyloroplasty; patient w/ known Barrett's esophagus. Discontinue if symptoms of oesophageal irritation develop eg, dysphagia, pain on swallowing, retrosternal pain or new/worsening heartburn. Osteonecrosis of the jaw associated w/ tooth extr &/or local infection (osteomyelitis). Perform dental exam w/ appropriate preventive dentistry prior to treatment. Avoid invasive dental procedures. Hypocalcaemia in patients w/ predisposing conditions eg, hypoparathyroidism, vit D deficiency & Ca malabsorption). Ensure adequate Ca & vit D intake. Atypical subtrochanteric & diaphyseal femoral fractures in patient under long-term treatment for osteoporosis. Pregnancy & lactation. Childn <18 yr w/ osteogenesis imperfecta.