IntroductionO steoporosis is a prevalent disease that affects more than 10 million Americans. The lifetime risk of an osteoporosisrelated fracture is 50% for Caucasian women and 25% for men. Hip fractures carry a 10% to 20% increase in mortality rate within the first year after fracture. (1) The burden of the hip and other fractures can result in chronic pain, disability and other indices of reduced quality of life.Amidst these sobering statistics is the welcome advent over the past two decades of effective pharmacological therapies that reduce fracture risk. The therapies approved for the management of osteoporosis include bisphosphonates, raloxifene (a selective estrogen-receptor modulator), calcitonin, denosumab, strontium ranelate, and parathyroid hormone and PTH(1-84)]. The fulllength PTH molecule and its foreshortened amino-terminal fragment (teriparatide) are currently the only osteoanabolic agents approved for use. PTH(1-84) is not available in the United States. In November, 2002, teriparatide was approved by the U.S. Food and Drug Administration (FDA) for the treatment of postmenopausal osteoporosis and, later, in men. The approval came with restrictions in duration of therapy (18-24 months) and was limited to individuals with advanced osteoporosis at high risk for fracture. Reasons for these limitations relate, at least in part, to the unexpected occurrence of osteosarcoma and other bone neoplasms in Fischer 344 rat toxicity studies. In fact, the pivotal phase 3 trial of teriparatide was suspended when these rat toxicity data became available. The effects on rats was doseand duration-dependent, with rats being treated for approximately 80% of their lifetime and at doses three to 58 times the currently approved human dose. (2) Similar toxicity was seen for PTH(1-84) (3) Given the clear-cut efficacy data when the results of the abbreviated clinical trial results for teriparatide were analyzed, the FDA and equivalent other agencies in Europe and elsewhere granted approval of teriparatide with the stipulations that it should be used for no longer than 2 years. In the United States, the drug carries a ''black box warning'' and contraindicates its use in patients with existing risk factors for osteosarcoma, including Paget's disease of bone, prior skeletal radiation, and children with open epiphyses.Teriparatide has now been used in the United States for 10 years. With a decade of experience, it is timely to review the efficacy and safety profile of this medication. PTH(1-84) will also be reviewed. This perspective will be limited to PTH formulations that are available for the treatment of osteoporosis; we will not be discussing other anabolic agents that are currently being studied but are not yet approved, such as the sclerostin antibody (http://clinicaltrials.gov/ct2/results?term ¼ sclerostin þ anti-þ antibody). PTH mechanisms of actionTeriparatide is an amino-terminal fragment of PTH that is biologically identical to the amino-terminal fragment of human PTH. This fragment contains all the classical bio...

Altered prolactin and thyrotropin responses to the TRH test in parkinsonian patients are held to indicate an impairment of the tubero-infundibular dopaminergic axis (TIDA). We correlated the plasmatic prolactin (PRL), thyrotropin (TSH) and somatotropin (GH) responses to TRH and bromocriptine + TRH of 12 parkinsonian patients, who had never received anti-parkinsonian drugs, with the severity, the duration, the age of onset and the dopamine-dependence of the motor symptomatology as indicated by the therapeutic response to a six-month oral treatment with bromocriptine. Patients with basal motor impairment over 9 on the Webster Rating Scale (WRS), those with duration of the disease over 24 months and those with onset earlier than 55 years of age showed lower PRL responses than the respectively matched subgroups. Patients showing a therapeutic motor improvement over 50% on the WRS (dopamine-dependent or "responder") showed lower PRL and TSH and higher GH responses than the non-responders. These findings suggest that the TIDA impairment described in Parkinson's disease develops along with the progressive course of the extrapyramidal involvement and is strictly correlated with the dopamine-dependence of the motor impairment.