The effect of two different doses of oral clodronate on pain in patients with bone metastases

The aim of this study was to evaluate the efficacy of low dose oral clodronate in palliation of pain arising from bone metastases (BM) and to determine the optimal oral clodronate dose which inhibits osteolysis caused by tumor. Fifty patients with bone pain caused by BM were included in this study. All were receiving antitumor chemotherapy or hormonal therapy. The patients were randomized into three groups according to the dose of clodronate. Groups A and B were given 800 mg/d and 1600 mg/d of oral clodronate respectively for 3 months. Group C was the control group. The effect of clodronate in pain palliation was evaluated with pain score, performance status, and changes in analgesic use. The effect on osteolysis was examined with urinary calcium, hydroxyproline (OHP) and serum cross-linked carboxyterminal telopeptide region of type I collagen (ICTP) levels. Group A contained 16 patients, and groups B and C contained 17 patients each. After 3 months use of oral clodronate, significant decrease in the pain score of groups A and B was noted when, compared to group C (P=0.024 andP=0.007, respectively) The analgesic use of 11 patients in group A (69%) and 8 patients in group B (47%) was decreased, but only the decrease in group A was statistically significant (P=0.038). Pain score increased in 5 patients in group C (29%), and 3 patients in groups A (19%) and B (18%) each. Urinary calcium, OHP and serum ICTP levels increased in group C and decreased in groups A and B, but only the decrease of urinary calcium levels of group B was significant (P=0.003). In conclusion, low dose (800 mg/d) oral clodronate seems to be as effective as standard dose (1600 mg/d) in palliation of bone pain secondary to BM.