Renal Flashcards
What are the 2 aquaretic diuretics? How do they work?
Conivaptan
Tolvaptan
-ADH blockers
What drug is used to reduce urine output in patients with central diabetes insipidus?
Desmopressin (ADH analog)
What area of the kidney do Thiazide diuretics act on? What symport do they inhibit?
block solute reabsorption in the early distal tubule by inhibiting Na+Cl- symport
Which 2 classes of diuretics work in the proximal tubule?
Carbonic anhydrase inhibitors (acetazolamide, methazolamide, dichlorphenamide) & osmotic diuretics (mannitol, urea, isorbide)
Which class of diuretics work in the thick ascending limb? Which symport system do they inhibit?
- Loop diuretics (furosemide, bumetanide, torsemide, ethacrynic acid)
- inhibit Na+K+2Cl- symport
Which class of drugs act in the late distal tubule?
Na+ channel inhibitors / K+ sparing (amiloride, triamterene)
What is the mechanism of acetazolamide and others in its class?
Carbonic anhydrase inhibitors–>
increase intracellular H+ –> decrease Na/H+ exchanger –> decrease Na+ & HCO3- reabsorption
What are 4 uses of Mannitol? 1 risk?
USE:
drug overdose; shock or major surgery; differential diagnosis of oliguria; reduce intraocular or intracranial pressure
RISK:
increased hydrostatic pressure may induce pulmonary edema
What are some possible plasma level complications from loop diuretics and thiazide diuretics?
- Hyponatremia, hypokalemia (w/chronic use), hypomagnesemia
- hyperbicarbonatemia (contraction alkalosis), hyperuricemia (stones, gout), increase in BUN w/ or w/o increase in creatinine (hepatic encephalopathy)
- hypercalciuria
What are 2 important risks of loop diuretics?
- onset or unmask diabetes mellitus (hypokalemia affects beta cells of pancreas)
- ototoxicity (pts with renal failure are at most risk due to higher doses needed)
Which class can be used in the treatment of hypercalciuria?
thiazides (can combine with amiloride - K+ sparing which also increases Ca++ reabsorption)
What class may be used to treat nephrogenic diabetes insipidus? How?
Thiazides- contract ECF volume leading to decreased tubular fluid and decreased volume of voided urine (Allow for more concentrated urine to form)
What drug is used to treat Li-induced polyuria?
Amiloride (aldosterone-independent K+ sparing diuretic)
What is the main clinical complication of K+ sparing diuretics? For what patients are they contraindicated?
- hyperkalemia
- contraindicated in renal failure; pts on ACE inhibitors; liver cirrhosis
What are some side effects of spironolactone?
competitive antagonist of androgen receptors –>
- males: gynecomastia, erectile dysfunction, libido loss
- females: menstrual irregularities, breast soreness