Clodronate therapy of metastatic bone disease in patients with prostatic carcinoma.

Metastatic bone disease represents the most disabling complication in patients with prostatic carcinoma. In an open multicenter trial 80 out of 92 patients with bone metastasis due to prostatic carcinoma experienced a dramatic improvement of bone pain after treatment with 300 mg clodronate infused intravenously daily for 10 days. Further to this, 56 patients were randomly allocated to four single-blind controlled therapeutic trials, assessing bone pain by daily consumption of analgesic drugs and by visual analogue scale. In the first protocol the effects of 2 weeks' treatment with intravenous infusion of either 300 mg clodronate dissolved in 500 ml saline (7 patients) or 500 ml saline (6 patients) were compared. The differences in both pain score and analgesic consumption were so striking that the trial was not extended for ethical reasons and all patients on placebo were given clodronate intravenously. Oral administration of 1200 mg clodronate for 2 weeks was completely ineffective in 11 patients. Intramuscular administration of 100 mg clodronate for 2 weeks induced in 12 patients a significant fall in analgesic consumption but not in the pain score. In most of the 13 patients given clodronate intravenously for 2 weeks bone pain relapsed fairly soon. However, in 18 patients a maintenance therapy with 1200 mg clodronate/day for at least 6 weeks after a 2-week intravenous treatment course did prevent the relapse of bone pain. In all patients given clodronate routine biochemical examination was carried out during and after treatment. For an overall follow-up of 42 patient-years hematologic toxicity was never observed. These results confirm that clodronate represents the most effective and convenient conservative treatment of patients with painful bone metastasis from prostatic carcinoma.