Overview:
The reduction of bone mass with distortion of the micro architecture is termed as osteoporosis; a reduction in the mineral content is termed as oesteopenia. Osteoporotic bone can fracture easily after minimal trauma. The commonest causes of osteoporosis are postmenopausal deficiency of oestrogen and age related deterioration in bone haemostasis, but it can also result from other factors such as excessive glucocorticoids or thyroxine administration and can take place secondary to conditions such as rheumatoid arthritis. Since life expectancy has increased significantly, osteoporosis has become an important public health problem and drugs that prevent its development are being sought actively.
What is Osteoporosis
Current Treatment of Osteoporosis:
Potential New Therapies in Osteoporosis:
All current above mentioned drugs used in osteoporosis inhibit bone resorption. They can increase bone mineral density and decrease the risk of fractures. But they do not generally produce a marked increase in bone mass and the reduction of fracture risk is not usually more than 50% of the risk in untreated subjects. Consequently, there is now growing interest in the possible value of compounds that simulate bone formation- alone or in combination with resorptive drugs. Some contenders are parathormone (PTH), IGF-1 and growth hormone. PTH is the most promising of these. When given intermittently in low doses it potently stimulates both trabecular and cortical bone growth. Both recombinant PTH itself and the recombinant peptide fragment are in phase III trial.
Potential anabolic agents being considered for future development are fluoride and the statins. These last, commonly given to reduce blood cholesterol have been shown to increase the gene expression of bone morphogenic protein 2 and to increase bone formation in vitro.
Possible new antiresorptive agents include osteoprotegerin- a physiological inhibitor of bone resorption which has shown promise in early clinical trials and thiazides which have a small effect in slowing bone loss and might be of value in combination therapy.
It seems that there is likely to be a significant break through in fracture prevention in the reasonably near future.
