Term
| What are the 5 major classes of diuretics? |
|
Definition
thiazides
loop
carbonic anhydrase
k sparing
osmotic |
|
|
Term
| What are the clinical applications of diuretics? |
|
Definition
CHF, Kidney disease, hepatic cirrhosis, idiopathic edema
non-edematous states: HTN, nephrolitiasis, hpercalcemia, diabetes insipidus |
|
|
Term
| Name the thiazide diuretics and where do they act? |
|
Definition
chlorothiazide, cyclothiazide, ... anything with thiazide
They act at the distal convoluted tubule to increase excretion of Na+ and Cl-
thiazides affect salt transport and they all have equal efficacy, differeing only in potency. |
|
|
Term
| What is the most useful diuretic agent in traetment of recurrent Ca stones? |
|
Definition
| thiazides because they cause hypercalcemia and hypocalciurea. |
|
|
Term
| Name the two thiazide like diuretics and how are they different than thiazide? |
|
Definition
| indapamide and metolazone and they are useful in renal failure |
|
|
Term
| How do thiazides help in nephrogenic diabetes insipidus? |
|
Definition
| it's a paradoxical effect. Urine changes from hypo-osmolar to hyper osmolar and this increased th reabsorption at the proximal tubule? maybe by increasing the effectiveness of the channels and stuff? |
|
|
Term
| What is a main difference between thiazide diuretics and loop diuretics? |
|
Definition
| thiazides decrease the urine excretion of ca while loop diuretics increase the excretion of ca. |
|
|
Term
| Name a carbonic anhydrase inhibitor and where it acts and also what it is also useful for. |
|
Definition
acetazolamide acts at the prox convoluted tubule to decrease the reabsorption of bicarbonate.
But they are more often used for other pharm actions rather than diuretic effect because they are less efficacious than the thiazides or loops. For example, open angle glaucoma by decreasing the production of aqueous humor. Also useful in acute mountain sickness as a prophylactic. |
|
|
Term
| In what patients do you want to avoid carbonic anhydrase inhibitors (acetazolamide)? |
|
Definition
patients with cirrhosis bc can lead to hepatic encephalopathy.
But it's useful in correcting metabolic alkalosis, mildly |
|
|
Term
| What are the loop diuretics or high ceiling? |
|
Definition
inihbitiors of na, k, 2cl symport or cotransport
bumetadnide, furosemide, torsemide and ethacrynic acid |
|
|
Term
| Where do loop diuretics act? |
|
Definition
| thick ascending limp of loh |
|
|
Term
| In what patients are loop diuretics most effective? |
|
Definition
| those with poor renal function or who have not responded to thiazeds or other diuretics. the thick ascending LOH is where most of the reabsorption of NaCl occurs so 25-30% of it is excreted. Madd amounts of na is lost and rapid (4hrs) rid of edema and blood volume. |
|
|
Term
| How do loop diuretics affect calcium? |
|
Definition
| hypercalciurea, hypocalcinemia |
|
|
Term
| what are some significant adverse effects of furosemide and loop diuretics? |
|
Definition
significant abnormalities of fluid and electrolyte balance, ototoxicity-both auditory and vestibular. Ethacrynic is the most ototoxic and increases with concurrent use of aminoglycosides.
decreases hdl - not a great choice for patients with hyperlipidemia |
|
|
Term
| what are the k sparing diuretics? |
|
Definition
there are two aldosterone antagonists that work at the cortical collecting tubule and late distal tubule - spironolactone and eplerenone
then there are triamterene and amiloride which block na channels in the principal cells in the late distal tubule and collecting duct which in turn decreases k excretion. na excretion is mild but effect on k sparing is good - their action doesnt depend on the presence of aldosterone thus have activity even in patients with addisons disease. |
|
|
Term
| Which aldosterone antagonist doesn't cause gynecomastia? |
|
Definition
| eplerenone while spironolactone does. |
|
|
Term
| What are the osmotic diuretics? |
|
Definition
| mannitol, sorbitol, urea and all are injected parenterally |
|
|
Term
| how do osmotic diuretics act? |
|
Definition
all are injected parenterally and enter the renal tubule by filtration! The only diuretics that do.
in the prox convoluted and thin descending loh h20 is excreted greatly |
|
|
Term
| What are the uses of osmotic diuretics? |
|
Definition
maintain urine flow following acute toxic ingestion of substances capable of producing acute renal failure. Also used in pts with increased intracranial pressure or acute renal failure due to shock, drug toxicities and trauma.
Not useful in conditions with Na rentention bc excretes h20. |
|
|
Term
| Filtered sodium chloride enters the cells in the thick ascending limb of the loop of Henle via Na-K-2Cl cotransporters in the luminal (or apical) membrane (figure 1) [5-7]. Although this process is electrically neutral, most of the reabsorbed potassium leaks back into the lumen to drive further sodium chloride transport [4]. This movement of cationic potassium into the lumen plus the movement of reabsorbed chloride (via a chloride channel) out of the cell into the peritubular capillary generates a net positive current from the capillary into the lumen. The ensuing lumen electropositivity creates an electrical gradient that promotes the passive reabsorption of cations — sodium, and, to a lesser degree, calcium, and magnesium — via the paracellular pathway between the cells [8]. (See "Chapter 4A: Cell model for loop of Henle transport".) |
|
Definition
|
|
