Current management of malignant hypercalcaemia

Urinary excretion of aminohydroxypropylidene bisphosphonate in cancer patients after single intravenous infusions

The effect of the rate of infusion of disodium aminohydroxypropylidene bisphosphonate (APD; CGP 23339A), an inhibitor of bone resorption, on urinary excretion of this agent was studied in a randomized open-label study in 20 cancer patients. Ten patients received 60 mg of APD over 4 h, and the remaining 10 patients received the same dose over 24 h. Urine collected during specified intervals for 72 h after the start of the infusion was analyzed by high-performance liquid chromatography for unchanged APD. Mild and transient adverse experiences were observed in 12 (60%) patients; the most common were headache, fever, and phlebitis at the infusion site. No clinically significant laboratory abnormalities were observed, and none of the experiences were serious enough to require discontinuation of treatment. Cumulative urinary excretion of APD was a linear function of time, increasing rapidly after both the 4- and 24-h infusions were started. The mean (+/- standard deviation) cumulative urinary excretion of APD was 51.1 +/- 13.0% of the dose in the 20 patients, 55.0 +/- 15.0% in the 10 patients given the 4-h infusion, and 47.2 +/- 9.9% in the 10 patients receiving the 24-h infusion. Thus, the rate of infusion of the 60-mg dose did not influence retention of APD at 72 h after the start of therapy. Similarly, the presence or absence of bone metastases did not influence cumulative urinary excretion or the retention of APD.

Paraneoplastic syndromes associated with lung cancer

Paraneoplastic phenomena associated with primary lung cancer have diverse initial manifestations and epitomize the systemic nature of human malignant disease. The spectrum of clinical features in patients with paraneoplastic syndromes ranges from mild systemic or cutaneous disease to hypercoagulability and severe neuromyopathic disorders. Although the diagnosis is often one of exclusion, an improved understanding of the pathogenesis involved in some of these syndromes has provided another means of recognizing the disorders and perhaps treating the affected patients. Proposed mechanisms of paraneoplastic processes include the aberrant release of humoral mediators such as hormones and hormone-like peptides, cytokines, and antibodies. In this update, we review the potential mechanisms, diagnosis, and treatment of paraneoplastic syndromes associated with lung cancer.

Treatment of Severe Hypercalcemia in Primary Hyperparathyroidism with Aminopropylidene Diphosphonate

Objective:

To test the clinical usefulness and potency for decreasing plasma calcium concentration of an intravenously administered diphosphonate (aminopropylide diphosphonate [APD]) in a patient with hypercalcemic crisis secondary to primary hyperparathyroidism, unresponsive to hydration and furosemide, and who was ineligible for surgery because of cardiac conduction defects.

Design:

Case report.

Setting:

Referred care setting.

Intervention:

The patient received APD 15 mg/d, dissolved in 100 mL of isotonic NaCl 0.9% and infused in one hour.

Main Outcome Measure:

Plasma calcium concentration.

Results:

The patient's plasma calcium concentration fell considerably in a few days. The concomitant decrease in urinary calcium excretion indicates that this fall is caused by a decreased entry of calcium to the extracellular fluid and not to increased renal calcium excretion. After nine days, a parathyroid adenoma was removed; plasma calcium concentration remained normal during the following three years.

Conclusions:

APD is a useful adjunct to medical therapy in patients with hypercalcemic crisis secondary to primary hyperparathyroidism.

Future horizons for calcitonin: a U.S. perspective

Injectable salmon calcitonin has been in use in the United States for more than a decade for the treatment of patients with postmenopausal osteoporosis, Paget's disease, and hypercalcemia. Sandoz Pharmaceuticals Corp. is currently in the process of developing a nasal formulation of salmon calcitonin. Studies are in progress to compare the efficacy of this nasal formulation with that of the injectable hormone in preventing bone loss and restoring bone, as well as in reducing pain associated with bone diseases. The rationale for development of a nasal formulation is to attempt to reduce the incidence of systemic side effects, inconvenience, and resulting noncompliance associated with the injectable product. In studies to date, the nasal form of calcitonin has been well tolerated by most subjects and was not notably associated with nasal irritation. The tolerability seen within the context of clinical trials suggests that a nasal formulation might be well accepted, even among asymptomatic osteoporotic patients. Asymptomatic patients with secondary osteoporosis due to steroid administration or solid organ transplantation may also be studied as possible candidates for the prophylactic use of this drug. Additional future research includes the development of an oral calcitonin agent.

Salmon calcitonin in the acute management of hypercalcemia

Salmon calcitonin has been used for the management of acute hypercalcemia for the past several years. Unlike other hypocalcemic agents, it is effective within 2 hours after first dosing. This pharmacologic agent shows peak effect at 24-48 hours and has a duration of action of 4-7 days in most cases. Its effectiveness may diminish thereafter despite continuous administration (the so-called "escape phenomenon"). Salmon calcitonin has been shown to be effective in the management of acute hypercalcemia due to a variety of causes, and, because of its low toxicity profile, it may be administered to patients with congestive heart failure or azotemia. Salmon calcitonin is also an analgesic agent in patients with pain associated with bone metastases and may be used in conjunction with other hypocalcemic agents such as mithramycin, the bisphosphonates, or gallium nitrate to prolong the clinical response to more than 1 week. Salmon calcitonin is therefore effective and safe in the management of acute hypercalcemia.