Short-term therapy with oral olpadronate in active Paget's disease of bone.

One of the aims of the treatment of Paget's disease with bisphosphonates should be the normalization of the activity of the disease with the shortest possible exposure to the drug. Olpadronate (OPD) is a new bisphosphonate characterized by the dimethylation of the amino group, its potency is near to alendronate, and more soluble in the digestive media than other aminobisphosphonates. We treated 46 patients (28 men and 18 women, mean age 70 years) with active Paget's disease with oral OPD, 200 mg/day for 12 +/- 2 days, except 2 patients who received 400 mg/day. Eight patients had never been treated before, and 38 had previously received antiosteolytic drugs. The period without treatment prior to OPD was (X +/- 1 SD) 14 +/- 12 months. Baseline bone alkaline phosphatase (BALP) (levels fell from (X +/- 1 SD) 54.0 +/- 62.7 IU/ml (range 22-396) to a lowest mean value of 16.2 +/- 6.4 IU/ml (range 8-45) (normal range 5-21 IU/ml). Forty patients normalized BALP values, in most of the cases within the first 3 months after OPD treatment. Two patients showed partial response (> 50% decrease from baseline), three patients presented poor response (< 50% decrease from baseline), and one patient did not respond at all. Two patients complained of gastric discomfort, and one patient had diarrhea, which disappeared after discontinuation of the drug. Follow-up was carried out on 36 patients; 22 patients are still in remission, with an average length of 9.0 +/- 2.6 months. Fourteen patients experienced relapse after 9 +/- 2 months remission. In conclusion, a 12-day treatment with 200 mg/day of OPD proved to be a very effective and well tolerated therapy of Paget's disease and induced biochemical remissions in the vast majority of patients, even in those with very active disease.