pharmacology

Question 1

where is blood filtered in the kidney?

Answer 1

glomerulus

Question 2

what is natiuresis?

Answer 2

the process of excretion of sodium in the urine

Question 3

what increases sodium excretion?

Answer 3

ventricular and atrial natriuretic peptides as well as calcitonin

Question 4

what conserves sodium?

Answer 4

chemicals such as aldosterone

Question 5

where is K appearing in the urine secreted from?

Answer 5

the collecting duct

Question 6

where is filtered potassium reabsorbed?

Answer 6

the proximal tubule and the loop of henle

Question 7

how is potassium transported into cells in the collecting duct?

Answer 7

via the N/K ATPase on the basolateral membrane

Question 8

what are diuretics?

Answer 8

drugs that ↑ the volume of urine produced by promoting the excretion of Na+, Cl-, HCO3 and water from the kidneys.

Question 9

what is the impact of diuretics?

Answer 9

↑ urine flow, altered pH and altered ionic composition of blood and urine

Question 10

when are diuretics used?

Answer 10

treatment of oedema and hypertension

Question 11

what are the different classes of diuretics?

Answer 11

Osmotic diuretics
Carbonic anhydrase inhibitors
Loop diuretics
Thiazide diuretics
Potassium sparing diuretics

Question 12

where do osmotic diuretics act?

Answer 12

proximal tubules
loop of henle
collecting duct

Question 13

what is the mechanism of osmotic diuretics?

Answer 13

inhibition of water and Na reabsorption

Question 14

where do carbonic anhydrase inhibitors act?

Answer 14

the proximal tubules

Question 15

what is the mechanism of carbonic anhydrase inhibitors?

Answer 15

inhibition of bicarbonate reabsorption

Question 16

where do loop diuretics act?

Answer 16

loop of henle (thick ascending limb)

Question 17

what is the mechanism of loop diuretics?

Answer 17

inhibition of Na, K and Cl

Question 18

where do thiazides act?

Answer 18

early distal tubule

Question 19

what is the mechanism of thiazides?

Answer 19

inhibition of Na and Cl cotransport

Question 20

where do K sparing diuretics act?

Answer 20

late distal tubule
collecting duct

Question 21

what is the mechanism of K sparing diuretics?

Answer 21

inhibition of Na reabsorption and K secretion

Question 22

what are some examples of osmotic diuretics?

Answer 22

mannitol, isosorbide, glycerine and urea

Question 23

what is the result of osmotic diuresis?

Answer 23

blood volume deacreased and a large volume of dilute urine produced

Question 24

what does mannitol do?

Answer 24

diuresis in the prevention of acute renal failure
excretion of toxic substances
reduce IOP and ICP and cerebral oedema

Question 25

what are the adverse effects of osmotic diuresis?

Answer 25

cardiovascular toxicity immediately after injection contraindicated in patients with HF

Question 26

what are some examples of carbonic anhydrase inhibitors?

Answer 26

Acetazolamide, Methazolamide

Question 27

what is the function of carbonic anhydrase in the proximal collecting tubule?

Answer 27

anhydrase plays a major role in acid/base balance ultimately leads to no Na or bicarbonate reabsorption

Question 28

what are some indications for carbonic anhydrase inhibitors?

Answer 28

raised IOP in open angle glaucoma ocular hypertension when monotherapy is inadequate

Question 29

what are some side affects of carbonic anhydrase inhibitors?

Answer 29

metabolic acidosis renal stones renal potassium wasting

Question 30

which binding site do loop diuretics act upon?

Answer 30

the chloride binding site, directly inhibiting the carrier

Question 31

what are the indications for loop diuretics?

Answer 31

water imbalances associated with congestive HF, KF and pulmonary oedema in patients with a high BP and less than 50% kidney function

Question 32

how do loop diuretics interact with other medications?

Answer 32

hypokalaemia associated with loop diuretics increases the risk of digoxin toxicity ( a med prescribed for congestive HF) corticosteroids can also cause hypokalaemia aminoglycosides can increase the risk of kidney damage NSAIDs can reduce the effect of loop diuretics

Question 33

what are some examples of thiazide diuretics?

Answer 33

hydrochlorothiazide, bendroflumethiazide

Question 34

what are thiazide diuretics used to treat?

Answer 34

high BP congestive HF oedema cirrhosis

Question 35

what ion do thiazides increase reabsorption of?

Answer 35

Ca reabsorption at the distal tubule

Question 36

what are the contraindications of thiazide diuretics?

Answer 36

hypotension gout renal failure lithium therapy hypokalaemia may worsen diabetes they reduce the clearance of uric acid, hence the gout contraindication

Question 37

why can thiazides and loop diuretics lead to digoxin toxicity?

Answer 37

Hypokalaemia resulting from loop diuretics and thiazides will potentiate the effect digoxin, thus increasing the risk of cardiac arrythmias

Question 38

how does digoxin work?

Answer 38

Digoxin is an inhibitor of the Na+/K+ ATPase pump and binds to the alpha subunit. This causes an increase in intracellular Na+

Question 39

which diuretics are potassium sparing?

Answer 39

aldosterone antagonists (eg spironolactone) sodium channel inhibitors (eg amiloride)

Question 40

what are the side affects of potassium sparing diuretics?

Answer 40

hyperkalaemia use with caution with meds that increase K, eg. ACEi

Question 41

which drugs reduce the efficacy of thiazides?

Answer 41

NSAIDs

Question 42

what does pharmacodynamics mean?

Answer 42

effects of drug on the body