Corticosteroid-induced bone loss. Prevention and management.

Osteoporosis is one of the most serious adverse effects experienced by patients receiving long term corticosteroid therapy. Bone loss occurs soon after corticosteroid therapy is initiated and results from a complex mechanism involving osteoblastic suppression and increased bone resorption. There are a number of factors that may increase the risk of corticosteroid-induced osteoporosis [smoking, excessive alcohol (ethanol) consumption, amenorrhoea, relative immobilisation, chronic obstructive pulmonary disease, inflammatory bowel disease, hypogonadism in men, organ transplantation]. The initial assessment of patients about to start taking corticosteroids should include measurement of spinal bone density, urinary calcium level and plasma calcifediol (25-hydroxycholecalciferol) level; serum testosterone levels should also be measured when hypogonadism is suspected. Many different drugs have been used to prevent osteoporosis in patients receiving long-term corticosteroid therapy, including thiazide diuretics, cholecalciferol (vitamin D) metabolites, bisphosphonates, calcitonin, fluoride, estrogens, anabolic steroids and progesterone. At present, however, published studies have failed to demonstrate a reduction in the rate of fracture using different preventive pharmacological therapies in patients being treated with corticosteroids on a continuous basis. Among the drugs studied, bisphosphonates (pamidronic acid and etidronic acid) and calcitonin appear to be effective in increasing bone density. Cholecalciferol preparations have been reported to be effective in some, but not all, studies. Limited data have shown positive results with thiazide diuretics, estrogen, progesterone and nandrolone. When treating patients with corticosteroids, the lowest effective dose should be used, with topical corticosteroids used whenever possible. Auranofin may be considered in patients with corticosteroid-dependent asthma. Patients should take as much physical activity as possible, maintain an adequate daily intake of calcium (1000 mg/day0 and cholecalciferol (400 to 800 U/day), stop smoking and avoid excessive alcohol intake. It is important to detect and treat hypogonadism in men, if present, and to replace gonadal hormones in postmenopausal women or amenorrhoeic premenopausal women, and to detect and correct cholecalciferol deficiency. A thiazide diuretic should be considered if hypercalciuria is present (urinary calcium excretion in excess of 4 mg/kg/day). High-risk patients and those with established osteoporosis should be treated with bisphosphonates (cyclical etidronic acid or intravenous pamidronic acid), nasal calcitonin, or calcifediol or calcitriol. Patients receiving cholecalciferol preparations should be carefully monitored for hypercalciuria and hypecalcaemia.