Pamidronic acid and Paget's disease: new indication. Short-course treatment

(1) Pamidronic acid, a diphosphonate, is now approved for intravenous treatment of Paget's disease in France. Treatment is given over two to three days, in hospital, and can be repeated six months later. (2) The clinical file contains only non comparative trial data suggesting that a total dose of 180-210 mg has a clinical benefit in most patients and tends to normalise biochemical criteria thought to reflect disease progression. (3) Because no comparative trials have been done, there is no way of knowing whether a short course of intravenous pamidronic acid is any more or less effective that long-term oral etidronic acid or tiludronic acid therapy. However, in the non comparative trials a number of patients who had become resistant to oral diphosphonate therapy had a clinical and/or biochemical response to intravenous pamidronic acid. (4) While intravenous pamidronic acid is well tolerated overall, the precise incidence of its adverse effects on bone (transient increase in pain, osteomalacia) and the eyes (uveitis) is not known.