Clodronate as a single-dose intravenous infusion effectively provides short-term correction of malignant hypercalcemia.

The efficacy and safety of a single intravenous (I.V.) infusion of clodronate 1500 mg or 900 mg was compared with a single I.V. infusion of pamidronate 90 mg in the treatment of malignant hypercalcemia. Primary efficacy data from two separate, but parallel, randomized double-blind controlled multi-center studies (N = 63), involving patients with malignant hypercalcemia (S-Ca(cor) > 2.68 mmol/l), were pooled along with results from a study (N = 4), in which an open I.V. phase was followed by a randomized oral phase. The primary efficacy variable, the proportion of normocalcemic patients at day 5 could be evaluated from 51 subjects. Of them, 21 were in the clodronate 1500 mg group, 10 in the clodronate 900 mg group and 20 in the pamidronate 90 mg group. After the rehydration, the patients were given a single I.V. infusion of clodronate 1500 mg, clodronate 900 mg or pamidronate 90 mg. The patients were followed up for five days and S-Ca(cor) was measured daily. At day 5, a total of 16 patients (76%) in the clodronate 1500 mg group, six patients (60%) in the clodronate 900 mg group and 17 patients (85%) in the pamidronate 90 mg group were normocalcemic, the differences between the treatment groups being statistically non-significant. The differences in the mean S-Ca(cor) between the treatment groups were statistically non-significant. I.V. clodronate given either as 900 mg or 1500 mg single-dose was safe and well tolerated.