Renal safety of 1-hour pamidronate infusion for breast cancer and multiple myeloma patients: comparison between clinical trials and population-based database.

Purpose: The American Society of Clinical Oncology recommends infusion of pamidronate over 2 hours to avoid renal deterioration, although there are data to suggest that 1-hour infusions may be safe.

Methods: Prevalence of renal deterioration with 1-hour pamidronate infusions from a population database was compared to renal deterioration with 2-hour pamidronate infusions, in randomised, controlled, trials. A cost-minimisation analysis, comparing the 1- and 2-hour pamidronate infusions, and the 15-minute infusion of zoledronic acid, was performed with a sensitivity analysis that varied the opportunity cost of time in the treatment room.

Results: Renal deterioration occurred in 7.7% of 169 patients with multiple myeloma and metastatic breast cancer. There is no evidence that this differs from the 10% reported in randomised, controlled, trials (one-tailed binomial test, P = 0.3874). A subgroup analysis showed that renal deterioration occurred in 15 and 1.1% of patients with multiple myeloma and metastatic breast cancer, respectively. The median increase in serum creatinine was 13 and 7% in the multiple myeloma and breast cancer groups, respectively. The respective costs/dose (drug/labour/supplies) of pamidronate and zoledronic acid are 325 dollars and 610 dollars. Cost neutrality occurs if the opportunity cost of chair time is 6.33 dollars/minute for pamidronate 1-hour versus zoledronic acid, and 2.71 dollars/minute for pamidronate 2-hour versus zoledronic acid. If a median 4 dollars/minute is used, the respective costs of pamidronate 1-hour, 2-hour, and zoledronic acid infusions are 685 dollars, 925 dollars, and 790 dollars/cycle.

Conclusions: Prevalence of renal deterioration with 1-hour pamidronate infusions from a population database was not significantly different to 2-hour pamidronate infusions in clinical trials. Our findings suggest further support for the safety of 1-hour pamidronate infusions. Pamidronate via 1-hour infusion is less expensive than zoledronic acid.