Analgesic activity of high-dose intravenous calcitonin in cancer patients with bone metastases

We undertook a prospective, nonrandomized study with the objective to evaluate the efficacy of salmon calcitonin (sCT) in controlling pain secondary to bone metastases. Our study population consisted of 45 cancer patients with bone metastases (26 men) with a mean age of 64 years (range, 48-70) who had completed chemotherapy, hormonal therapy and radiation therapy at least 30 days prior to enrollment in the study, and had intractable pain despite the use of common analgesics (acetaminophen, nonsteroidal anti-inflammatory agents, opioids) and bisphosphonates. The study medication was a 300-IU dose of sCT administered intravenously daily for 5 consecutive days and repeated every two weeks until no response was noticeable. The analgesic efficacy of sCT was evaluated by means of Huskisson's visual analogue scale and Keele's pain scale; the daily consumption of analgesic drugs and performance status were also monitored. None of the patients managed to completely discontinue the use of other analgesics, but 5 patients (11% of the total number) had an analgesic response that lasted 4 weeks and less than 5% of the patients continued to respond for 6 weeks. No significant side effects were observed. Our data show that intravenous calcitonin administered in a relatively high dose has a very limited therapeutic potential as an adjuvant analgesic for a short period of time in selected cancer patients with bone metastases.