Increasing bone density in myeloma patients after the administration of clodronate.

The use of bisphosphonates in hypercalcemia is fully accepted, but the long term therapy with bisphosphonates is still controversial. The aim of our study was to evaluate the influence of clodronate on the bone density of myeloma patients. 20 patients were included in the study. A total dose of 3000 mg clodronate was administered in 4 to 6 hourly infusions of 600 mg a day, once in 3 months. The effect of clodronate on bone density was evaluated by CT-densitometry over a period of 6 months. At the beginning of May 1994, 15 patients had completed at least 2 estimations of bone density. The amount of hydroxyapatite had increased in 9 patients, remained unchanged in 1 of them, and decreased in 4 of them during the 6 months. The mean bone density before the administration of clodronate was -2.6 SD (standard deviation of European standard bone density for the respective age and sex). After 6 months of therapy, bone density had increased to -2.3 SD. The mean amount of hydroxyapatite in spongiosa rose from the mean value of 32.71 mg/ml before clodronate administration to 38.91 mg/ml after the 6-month treatment period. The mean increase in calciumhydroxyapatite in trabecular bone mass was 6.2 mg. Clodronate contributed to alleviating bone pain in the majority of patients, but this effect is difficult to evaluate because of other treatment modalities administered concomitantly. The tolerance of clodronate was very good. No impairments of renal function, nor other adverse effects were observed. Only in 2 patients the decrease in calcium concentration caused slight tetania.(ABSTRACT TRUNCATED AT 250 WORDS)