Hormonal Loop diuretics

Hypercalcemia Carefully monitor standard hypercalcemia-related metabolic parameters, such as serum levels of calcium, phosphate, and magnesium, as well as serum creatinine. Do not use loop diuretics until the patient is adequately rehydrated use with caution in combination with zoledronic acid in order to avoid hypocalcemia. Use zoledronic acid with caution with other nephrotoxic drugs. Concomitant use with estrogen/hormone replacement therapy (alendronate) Two clinical studies have shown that the degree of suppression of bone turnover (as assessed by mineralizing surface) was significantly greater with the combination than with either component alone. 

Other drugs that may interact with cardiac glycosides include the following Albuterol, amphotericin B, beta-blockers, calcium, disopyramide, loop diuretics, nondepolarizing muscle relaxants, potassium-sparing diuretics, succinylcholine, sympathomimetics, thiazide diuretics, thioamines, and thyroid hormones. 

Agents that may increase theophylline levels include allopurinol, beta blockers (nonselective), calcium channel blockers, cimetidine, oral contraceptives, corticosteroids, disulfiram, ephedrine, influenza virus vaccine, interferon, macrolides, mexiletine, quinolones, thiabendazole, thyroid hormones, carbamazepine, isoniazid, and loop diuretics. 

Receptors can mediate the action of endogenous signalling compounds and may therefore be viewed as regulatory proteins. Such receptors are the physiological targets for neurotransmitters and hormones. Other types of receptors include enzyme proteins, transport proteins and structural proteins. For example, statins inhibit an enzyme catalysing the synthesis of cholesterol and loop diuretics inhibit an enzyme that facilitates the re-uptake of salt in primary urine. 

Rejnmark L et al Effects of long-term treatment with loop diuretics on bone mineral density, calciotropic hormones and bone turnover. 3 Intern Med 2005 257 176. [PMID 15656876]... 

Many diuretic agents (loop diuretics, thiazides, amiloride, and triamterene) exert their effects on specific membrane transport proteins in renal tubular epithelial cells. Other diuretics exert osmotic effects that prevent water reabsorption (mannitol), inhibit enzymes (acetazolamide), or interfere with hormone receptors in renal epithelial cells (spironolactone). 

In patients with the syndrome of inappropriate secretion of antidiuretic hormone and symptomatic hypotonic hyponatremia, the most efficient means of correcting the hyponatremia involves the administration of 3% saline in conjunction with a loop diuretic. 

Answer D. Drugs that decrease extracellular potassium such as the thiazide and loop diuretics and adrenal glucocorticoids will lead to an increased requirement for insulin by making it more difficult to release the hormone from the B cells of the pancreas. Spironolactone is K sparing, tends to cause hyperkalemia, and does not interfere with the release of insulin. Stress conditions such as examinations also increase insulin requirement. 

Reduced absorption from the Gl tract has many causes, some of which are diarrhea, insufficient dietary intake, damage to the small intestine that may inhibit absorption, and malnutrition. Some common causes of excessive loss in the urine include diureses owing to alcohol, loop diuretics, and glycosuria. Other factors that may lead to hypomagnesemia are hypersecretion of aldosterone (causing hypernatremia), ADH, or thyroid hormone and excessive vitamin D (causing hypercalcemia) and intravenous fluids. 

Zinc is the prosthetic group for many enzymes. It is also incorporated into the receptor proteins for steroid and thyroid hormones, calcitriol and vitamin A. Recommended daily intake of zinc is 10 mg/day. Zinc is found in all tissues of the body, but it is particularly high in the bone, liver and kidney. Zinc deficiency causes growth retardation, decreased wound healing and hypogonadism (i.e. much delayed puberty). It is only normally seen in populations whose diet is based on unleavened wholemeal bread, because wheat flour does not provide much zinc, and that which is available is bound to phytate. Phytate also inhibits the absorption of iron. Zinc depletion may also be caused by drugs such as thiazide and loop diuretics, and alcohol. Zinc deficiency can be successfully treated with replacement zinc therapy. 

See Table 15-6. Potassium-sparing diuretics are most useful in states of mineralocorticoid excess or hyperaldosteronism (also called aldosteronism), due either to primary hypersecretion (Conn s syndrome, ectopic adrenocorticotropic hormone production) or secondary hyperaldosteronism (evoked by heart failure, hepatic cirrhosis, nephrotic syndrome, or other conditions associated with diminished effective intravascular volume). Use of diuretics such as thiazides or loop agents can cause or exacerbate volume contraction and may cause secondary hyperaldosteronism. In the setting of enhanced mineralocorticoid secretion and excessive delivery of Na+ to distal nephron sites, renal K+ wasting occurs. Potassium-sparing diuretics of either type may be used in this setting to blunt the K+ secretory response. 

Because K+ does not recycle across the apical membrane of the distal convoluted tubule as it does in the loop of Henle, there is no lumen-positive potential in this segment, and Ca2+ and Mg2+ are not driven out of the tubular lumen by electrical forces. However, Ca2+ is actively reabsorbed by the distal convoluted tubule epithelial cell via an apical Ca2+ channel and basolateral Na+/Ca2+ exchanger (Figure 15-5). This process is regulated by parathyroid hormone. As will be seen below, the differences in the mechanism of Ca2+ transport in the distal convoluted tubule and in the loop of Henle have important implications for the effects of various diuretics on Ca2+ transport. 

Dousa TP, Barnes LD. Lithium-induced diuretic effect of antidiuretic hormone in rats. Am J Physiol 1976 231 1754-1759. Jackson BA, Edwards RM, Dousa TR. Lithium-induced polyuria effect of lithium on adenylate cydate and adenosine 3 5 monophosphate phosphodisterase in medullary ascending limb of Henle s loop and in medullary collecting tubules. Endocrinol... 

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