(Chloro-4 phenyl) thiomethylene biphosphonate in Paget's bone disease.

Several biphosphonates (PCT) have been used as therapeutic agents for Paget's bone disease. CIPsMBP has recently been shown to have a significant antiosteoclastic activity while defect in mineralization was only apparent at high doses. For six months, we tested this drug in 23 pagetic patients distributed in three groups. Gr 1 (n = 5) receiving 200 mg/day showed a decrease of serum alkaline phosphatase (SAP) to 42 +/- 4% (p less than 0.01) of initial value (100%) while hydroxyprolinuria/creatinuria ratio (OH/Cr) dropped to 69 +/- 8% of baseline. In 4 patients receiving 400 mg/day, SAP improved to 48 +/- 9% of initial value (p less than 0.01) and OH/Cr to 40 +/- 3% (p less than 0.01). In the last group (n = 14) receiving 200 mg/day for 3 months, and 400 mg/day thereafter up to the 6th month SAP reduced to 53 +/- 4% and OH/Cr to 62 +/- 6% of initial value (p less than 0.01). Clinical improvement was significant from the first month of treatment. No resistance (mean decrease of SAP lower than 30%) was recorded and no radiological or clinical evidence of mineralization defect appeared. The clinical and biological tolerance was excellent throughout the study.