Kidney Disease Treatment Flashcards
What are the 5 classes of diuretics and what is their function
Thiazides: treat oedema. Inhibit the reabsorption of sodium and chloride in the distal tubule of the nephron.
Loop diuretics: act on the loop of Henle. Block the chloride pump, affecting the reabsorption of chloride and sodium.
Carbonic anhydrase inhibitors: slow down the movement of hydrogen ions, which leads to excretion of more sodium and bicarbonate in the urine.
Potassium-sparing diuretics: act on the distal tube segment. Usually supplements thiazides or loop diuretics.
Osmotic diuretics: increase the osmotic pressure of the filtrate. Thus reducing the amount of water normally reabsorbed by the tubules and loop of Henle.
What are the pharmacokinetics of acetazolamide?
Well absorbed after oral administration. Urine pH increases from the HCO3. Dose reduction is needed in renal disease.
What are some indications of carbonic anhydrase inhibitors?
Glaucoma (reduction in aqueous humor formation)
Metabolic alkalosis
Urinary alkalinization: increasing pH of urine makes uric acid more soluble.
Acute mountain sickness.
What are some toxicities of carbonic anhydrase inhibitors?
Hyperchloremic metabolic acidosis, renal stones, renal phosphorus wasting.
What are SGLT2 inhibitors and what are their function?
These drugs reduce glucose and sodium in the proximal tubule of the kidney. They have rapid absorption in the GI and Dapagliflozin has a half life of 10-12 hours.
What are some contraindications with SGLT2 inhibitors?
Can cause AKI, Genital fungal infection in women.
Where do loop diuretics act and what in their function?
Act at the apical membrane in the thick ascending limb of the loop of Henle. They inhibit Na and Cl reabsorption
What are some pharmacokinetic properties of loop diuretucs?
These agents are highly bound to albumin, rapidly absorbed in the GI (1-3 hours). Duration of furosemide is usually 2-3 hours. NSAIDs/probenecid can reduce the tubular secretion of loop diuretics.
What are clinical indications of loop diuretics?
Acute pulmonary oedema, acute renal failure, hyperkalemia. Anion overdose (bromide, fluoride, iodide)
What are some toxicities of loop diuretics?
Hypokalemic metabolic alkalosis, hearing loss, hyperuricemia (lower doses can avoid this). Can also cause skin rash, severe dehydration and hypercalciuria.
Where do thiazides act?
Inhibit Na/Cl transporter on the luminal membrane of the distal convulated tubule. Inhibits Na/Cl reaborption
What are some pharmacokinetic properties of chlorothiazide and indapamide?
Chlorothiazide is not very lipid soluble and must be given in large doses. Only thiazide available for parenteral administration. Chloro and Hydrochlorothizide have a DOA of 6-12 hrs.
Thiazides may reduce the risk osteoporotic fractures. (They enhance Ca+2 reaborption in the proximal and distal convoluted tubules.)
What are some toxicities of thiazides?
Hypokalaemia, hyperglycemia (stimulate ATP-sensitive K channels. This causes hyperpolarization of beta cells thereby inhibiting insulin release.)
Hyponatremia: increased thirst, hypovolemia-induced elevation of ADH.
What are the different classes of potassium-sparing diuretics?
Antagonism of mineralcorticoid receptors (spironolactone and eplerenone)
Inhibition of Na influx though ion channels in the luminal membrane (Amiloride and triamterene). These reduce Na absorption in the collecting tubules and ducts.
What are some pharmacokinetic properties of potassium-sparing diuretics?
Spironolactone inhibits the androgen receptor. This brings about gynecomastia and decreased libido. Eplerenone has greater selectivity for the mineralcorticoid receptor. Triamterene is metabolized in the liver.
