Comparison of the effects of intravenous pamidronate and oral clodronate on symptoms and bone resorption in patients with metastatic bone disease

Background: There is considerable debate as to the optimum schedule of bisphosphonate treatment in advanced malignancy. Short term studies using symptomatic response and biochemical markers of bone resorption may provide useful insight into differences between agents. Patients and methods: Fifty-one patients with metastatic bone disease were randomly allocated to either oral clodronate 1600 mg daily (group 1), intravenous clodronate followed by the same schedule of oral clodronate (group 2), or intravenous pamidronate 90 mg monthly (group 3). No radiotherapy was delivered or other systemic anticancer treatments were allowed except for long term endocrine therapy. Bone resorption was assessed by measurement of urinary collagen crosslinks. At each visit a pain score was recorded. Results: Symptomatic response was more frequent in the pamidronate group than in patients receiving clodronate. Nine of sixteen patients experienced a sustained improvement in pain score in the pamidronate-treated group, in contrast to only 4 of 16 and 2 of 11 patients in groups 1 and 2, respectively. There was a significant improvement in pain scores in the pamidronate arm compared with the clodronate treated patients after both three months of treatment (P <0.01) and at the last measurement (P < 0.05). Biochemical changes correlated with changes in the pain score (P = 0.01). Conclusion: Intravenous pamidronate appears to be more effective than oral clodronate in both controlling symptoms and suppressing bone resorption.