Thiazides inhibit calcium and magnesium excretion, the basic substrates of bone mineralization. Clinical investigations pointed already previously to their effectiveness in the prevention and treatment of osteoporosis despite a relatively small effect on the balance. This aroused some distrust and prevented their acceptance among preparations with this indication. They were indicated mainly in patients with hypercalciuria. The results of recent research indicate however their direct inhibition of osteoclasts and in particular stimulation of osteoblasts. This confirms results of clinical investigations which could not be explained previously. It may be foreseen that within a short time thiazides will become an important member in the spectrum of drugs used for the treatment of osteoporosis.

        Key words: Osteoporosis - Osteoclast - Osteoblast - Thiazides - Calcium.