click below
click below
Normal Size Small Size show me how
BBC Pharm
Ch. 26: Diuretics
Question | Answer |
---|---|
normally, what happens to the hydrogen ion produced in the tubule? | it is exchanged for sodium in the lumen, sodium and water travel through the tubule and gets excreted. |
name some CAI | acetazolamide, dorzolamide, brinzolamide. they are sulfonamides. |
what is the primary use of acetazolamide? | chronic treamtent of open angle glaucoma, becuase the same hydrogen ion dependent H/Na exchange is also responsible for fluid (aqueous humor) production in the eye. |
what is another use of acetazolamide? | mountain sickness; rimary role in this case is to reduce any associated respiratory alkalosis, via encouraging loss of excess bicarbonate through kidney. helps to reduce intracerebral pressures by decreasing CSF fluid |
CAI side effects? | hypokalemia, renal stone formation, drowsiness, and metabolic acidosis. hypokalemia occurs because of much potassium loss at the PCT. metabolic acidosis due to bicarb loss. |
these drugs act on the ascending loop of henle in the kidney, specifically blocking the Na/K/CC transporter, resulting in decreased sodium, potassium, and chloride reabsorption. | looop diuretics. |
loops enhance loss of what other ions? | calcium |
loops are useful for what? | they are the strongest class of diuretics, so good for any situation which water ust be diuresed rapidly or voluminously, including decompensated CHF. DOC for treatment of edema in renal disease. |
side effects of loops? | hypovolemia (because of its great effectiveness), toxicity, hypokalmeia, hyperuricemia, alkalosis. |
what is the most commonly used loop diuretic? | furosemide. torsamide is another. |
what class of drugs are loops? | sulfa drugs, except ethacrynic acid |
what class of diuretics are the most widely used? | thiazides. |
MOA of thiazides? | decrease sodium reabsorption at the sital tubule by inhibiting sodium/chloride transporter there. |
thiazides are the first line drug to treat what? | hypertension in all patients, except for those with renal disease, diabetes, CHF, and coronary artery disease (unstable angina, stable angina, MI history). |
why are urinary calcium stones prevented from further enlargement by thiazides? | thiazides caues the reabsorption of calcium, such that calcium is not excreted into the urine and into the collecting system where stones will form or grow in size. |
side effects of thiazides? | hypovolemia, as well as many that are similar to bu tless severe than loop diuretics. those side effects that are the same as those for loop diuretics occur for the same reasons. |
what is a popular thiazide? | hydrochlorothiazide |
these diuretics work in the collecting tubule and late distal collecting duct by inhibiting sodium reabsorption. | potassium sparing diuretic |
MOA of potassium sparing diuretic? | sodium reabsorption is inhibited, so the exchange with potassium cannot occur, so potassium is not lost. |
this K sparing diuretic inhibits the sodium reabsorption by inhibiting aldosterone, and is therefore an aldosterone antagonist | spironolactone |
these potassium sparing diuretics directly block sodium/potassium exchange in the late distal tubule and collecting duct | triamterine, amiloride |
what is the primary indicatoin for potassium sparing diuretic use? | hypertension. specifically, spironolactone is part of the drug of choice combo therapy for hypertension in those with hypertension who also have severe CHF. |
side effects of spironolactone? | hyperkalemia, lethargy, gynecomastia (because it mimics sex steroids), menstrual irregularities (for same reason). |
side effects of triamterone and amiloride? | leg cramps, hyperkalemia, hyperuricemia, high BUN. |
these are hydrophilic agents that are filtered through the glomeruli, dragging water with them. this group includes mannitol and urea. | osmotic agents. |
use of osmotic agents? | acute renal failure due to shock or trauma, to maintain urine flow following toxic ingestion of substances, and to decrease intracranial pressure (because they draw water form CSF into bloodstream, decreasing intracranial pressure). |