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12 Cards in this Set
- Front
- Back
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Describe the use of medicines which reduce steroid secretion or activity
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In the management of a limited number of clinical conditions (eg, Cushing's syndrome which cannot be treated surgically, endocrine therapy of breast or prostate cancer), medicines which reduce steroid secretion or activity have proven useful
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What are the important antiglucocorticoids?
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-Ketoconazole
-Metyrapone -Mitotane -RU-486/Mifepristone |
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Describe Ketoconazole
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-Antifungal antibiotic
-When given in high doses causes gynecomastia in male patients -Inhibits activities of several cytochrome P450-associated adrenal enzymes required in the biosynthesis of cholesterol, cortisol, and adrenal and testicular androgens -Can treat Cushing's syndrome |
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Describe Metyrapone
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-Selectively inhibits the 11-beta-hydroxylation of 11-desoxycortisol to form cortisol
-Glucocorticoid synthesis is selectively inhibited -The major toxicities of this compound relate to the excessive secretion of mineralocorticoids (hypokalemia, hypertension) and androgens (hirsutism, etc) caused by a "compensatory" increase in ACTH secretion |
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Describe Mitotane
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-A chemical relative of the insecticide DDT
-In low doses selectively toxic to cells of the adrenal cortex -After administration of increasing doses for several weeks the secretion of all steroids is markedly inhibited and patients will require supplementation with physiologic doses of glucocorticoids and often mineralocorticoids as well |
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Describe the use of Mitotane
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Used in the management of adrenal cortical carcinoma
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Describe the toxicity of Mitotane
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Toxicity (nausea, vomiting, anorexia, lethargy) is not common and permanent loss of adrenal cortical function can occur
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Describe RU 486/Mifepristone
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-Antagonizies the action of glucocorticoids and progestins at target tissues by binding without agonist activity to their respective receptors.
-Can serve as a progestin antagonist, especially as an abortifacient -Little clinical experience with this compound as an antiglucocorticoid |
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What are the important antimineralocorticoids?
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-Spironolactone
-Eplerenone |
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Describe Spironolactone
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A competitive antagonist of aldosterone and has proven useful in the treatment of several clinical states mediated by the secretion of excessive quantities of aldosterone (primary hyperaldosteronism, cirrhosis with ascites, congestive heart failure)
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Describe the toxicities of Spironolactone
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Primary toxicities are that of hyperkalemia and/or dehydration in some patients, and painful gynecomastic which occurs in the majority of men who take therapeutic doses for more than a few weeks
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Describe the use of spironolactone in patients with congestive heart failure
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Leads to improved survival
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