Effect of oral clodronate on bone pain

Although osteosclerotic metastases are characteristic of prostatic carcinoma, bone resorption is also accelerated. Since clodronate inhibits bone resorption and relieves bone pain, we have given it to patients with painful bone disease from prostatic cancer after failure of hormonal therapy. All patients received estramustine phosphate orally. Simultaneously they were randomly allocated to clodronate (36) and placebo (39) groups. Clodronate was given by mouth. The dose was 3.2 g for the first month, thereafter 1.6 g. Pain relief was more distinct in the clodronate group where one third of patients were totally free of bone pain. The use of analgesics stopped in 38% of patients on clodronate and in 18% on placebo which effect probably belongs to estramustine phosphate. Serum calcium concentration decreased more markedly in the clodronate group. Clodronate dose of 3.2 g seemed to be more potent than that of 1.6 g. Side effects were uncommon and occurred equally in both groups. No significant differences were seen in median survival or survival rates between the groups.