All of the following drugs cause osteoporosis except: September 2011
Correct Answer: Alendronate
Description: Ans. B: Alendronate Biphosphonates are the first drug of choice for treating post-menopausal osteoporosis PLEASE NOTE: A biphosphonate (pamidronate or zolendronic acid) inhibits osteoclastic bone resorption and is paicularly useful in hypercalcemia of malignancy as well Osteoporosis In osteoporosis the bone mineral density (BMD) is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered. Osteoporosis is defined by the World Health Organization (WHO) as a bone mineral density that is 2.5 standard detions or more below the mean peak bone mass (average of young, healthy adults) as measured by DXA; the term "established osteoporosis" includes the presence of a fragility fracture. The disease may be classified as primary type 1, primary type 2, or secondary. The form of osteoporosis most common in women after menopause is referred to as primary type 1 or postmenopausal osteoporosis. Primary type 2 osteoporosis or senile osteoporosis occurs after age 75 and is seen in both females and males at a ratio of 2:1. Finally, secondary osteoporosis may arise at any age and affects men and women equally. This form of osteoporosis results from chronic predisposing medical problems or disease, or prolonged use of medications such as glucocoicoids, when the disease is called steroid- or glucocoicoid-induced osteoporosis (SIOP or GIOP). Ceain medications have been associated with an increase in osteoporosis risk; only steroids and anticonvulsants are classically associated Steroid-induced osteoporosis (SIOP) arises due to use of glucocoicoids - analogous to Cushing's syndrome and involving mainly the axial skeleton. The synthetic glucocoicoid prescription drug prednisone is a main candidate after prolonged intake. Barbiturates, phenytoin and some other enzyme-inducing antiepileptics - These probably accelerate the metabolism of vitamin D. L-Thyroxine over-replacement may contribute to osteoporosis, in a similar fashion as thyrotoxicosis does. Anticoagulants - Long-term use of heparin is associated with a decrease in bone density, and warfarin (and related coumarins) have been linked with an increased risk in osteoporotic fracture in long-term use. Proton pump inhibitors - These drugs inhibit the production of stomach acid; it is thought that this interferes with calcium absorption. Chronic phosphate binding may also occur with aluminium-containing antacids. Thiazolidinediones (used for diabetes) - Rosiglitazone and possibly pioglitazone, inhibitors of PPAR-gamma, have been linked with an increased risk of osteoporosis and fracture. Chronic lithium therapy has been associated with osteoporosis The diagnosis of osteoporosis can be made using conventional radiography and by measuring the bone mineral density (BMD). The most popular method of measuring BMD is dual energy x-ray absorptiometry (DXA or DEXA). There are several medications used to treat osteoporosis, depending on gender. Medications themselves can be classified as antiresorptive or bone anabolic agents. Antiresorptive agents work primarily by reducing bone resorption, while bone anabolic agents build bone rather than inhibit resorption. Bisphosphonates are the main pharmacological measures for treatment. However, newer drugs have appeared in the 1990s, such as teriparatide and strontium ranelate. In confirmed osteoporosis, bisphosphonate drugs are the first-line treatment in women. The most often prescribed bisphosphonates are presently sodium alendronate, risedronate or ibandronate. Oral bisphosphonates are relatively poorly absorbed, and must therefore be taken on an empty stomach, with no food or drink to follow for the next 30 minutes. They are associated with inflammation of the esophagus (esophagitis) Estrogen replacement therapy remains a good treatment for prevention of osteoporosis. Selective Estrogen Receptor Modulators (SERMs) are a class of medications that act on the estrogen receptors throughout the body in a selective manner. Normally, bone mineral density (BMD) is tightly regulated by a balance between osteoblast and osteoclast activity in the trabecular bone. Estrogen has a major role in regulation of the bone formation-resorption equilibrium, as it stimulates osteoblast activity. Some SERMs such as raloxifene, act on the bone by slowing bone resorption by the osteoclasts. Raloxifene has the added advantage of reducing the risk of invasive breast cancer. Calcitonin works by directly inhibiting osteoclast activity the calcitonin receptor. Teriparatide (recombinant parathyroid hormone residues 1-34) has been shown to be effective in osteoporosis. It acts like parathyroid hormone and stimulates osteoblasts, thus increasing their activity. It is used mostly for patients with established osteoporosis (who have already fractured), have paicularly low BMD or several risk factors for fracture or cannot tolerate the oral bisphosphonates. Calcium salts come as water insoluble and soluble formulations. Calcium carbonate is the primary water insoluble drug, while calcium citrate, lactate, and gluconate are water soluble. Sodium fluoride treatment in patients with osteoporosis has been shown to cause skeletal changes such as pronounced bone density with increased number and thickness of trabeculae, coical thickening, and paial obliteration of the medullary space. Denosumab is a fully human monoclonal antibody that mimics the activity of osteoprotegerin. It binds to RANKL, thereby preventing RANKL from interacting with RANK and reducing its bone resorption. Oral strontium ranelate is an alternative oral treatment, belonging to a class of drugs called "dual action bone agents" (DABAs). Strontium ranelate has side effect benefits over the bisphosphonates, as it does not cause any form of upper GI side effect, which is the most common cause for medication withdrawal in osteoporosis. Calcium is required to suppo bone growth, bone healing and maintain bone strength and is one aspect of treatment for osteoporosis. A high intake of vitamin D reduces fractures in the elderly It did increase formation of kidney stones by 17%. Calcium and vitamin D are currently recommended for the primary prevention of osteoporosis and the primary and secondary prevention of osteoporotic fractures.
Category:
Pharmacology
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