Pamidronate

Abstract

OBJECTIVE: The primary objective of this article is to introduce readers to the use of a new agent, pamidronate. The article discusses its use in hypercalcemia of malignancy (HCM), osteolytic lesions, and Paget's disease. Pharmacokinetic data and clinical trials are reviewed, as well as adverse effects and dosage guidelines. DATA SOURCES: A MEDLINE search was used to identify English-language studies involving pamidronate for the period from 1970 to 1992. STUDY SELECTION: As comparative trials were few in number, trials using pamidronate as a single agent were also reviewed. DATA EXTRACTION: Sparse pharmacokinetic data were obtained from clinical trials. All clinical trials available at the time of publication that met the following criteria were reviewed: (1) allowed for adequate rehydration prior to drug therapy; (2) reported standardized and corrected serum calcium concentrations; (3) separated data obtained from patients who received pamidronate alone from those who received pamidronate and concurrent chemotherapy. RESULTS: Pamidronate has a pharmacologic profile similar to that of etidronate, but pamidronate is more potent and has a longer duration of effect. It has been investigated primarily in the treatment of HCM as well as in the treatment of osteolytic bone metastases and Paget's disease. In hypercalcemia of malignancy it appears to be as effective as established agents with the advantage that a single dose of pamidronate 90 mg iv provides a durable response. In Paget's disease chronic oral administration has also been shown to be effective in relieving bone pain. Adverse reactions with intravenous administration are transient and self-limiting and usually occur with the first dose. The most common adverse effect is a transient and self-limiting fever. Chronic oral administration of doses >600 mg/d is associated with gastrointestinal toxicities. CONCLUSIONS: Although more well-designed clinical trials comparing pamidronate with standard therapies and other available agents are necessary, initial results indicate that pamidronate is an effective and promising alternative for use in the treatment of HCM.