Use of alendronate in treatment of secondary osteoporosis from hypopituitarism: a case report.

The authors report a case of hypogonadotropic and hypothyrotropic partial hypopituitarism, being treated for over sixteen years with a substitution therapy consisting of estroprogestogenal hormones and L-thyroxine, presenting severe secondary osteoporosis, detected by densitometric examination (DEXA) of the medial and ultradistal sites of the non dominant radius. The patient was treated with alendronate (10 mg/die) for two years, in addition to the estroprogestogen therapy, resulting in a significant recovery of bone mass, equal to 16% compared to initial values, reaching near normal bone density values. On analysing the mechanisms of action of the bisphosphonates, the estrogens and the L-thyroxines, the authors suggest a synergic mechanism between the estrogen and the alendronate, which act on the bone turn-over at different times. Also, the alendronate would seem to antagonise the osteopenia of L-thyroxine, though this mechanism is still unknown.