Renal Pharmacology

Question 1

Furosemide

Answer 1

Sulphonamide
Loop diuretic - Act on the loop of henle, block the Na/K/Cl co transporter in thick ascending limb, also weak carbonic anhydrase inhibitors, can also act as a venodilator but this reduces blood filtered at glomerulus
Actively secreted into proximal tubule, effects are reduced with continues administration
Treatment of heart failure and hypertension and decreases ECF volume - hypokalmeia, gout + metabolic alkalosis

Question 2

Bumetanide

Answer 2

Sulphonamide
Loop diuretic - Act on the loop of henle, block the Na/K/Cl co transporter in thick ascending limb, also weak carbonic anhydrase inhibitors
Actively secreted into proximal tubule, effects are reduced with continues administration
Treatment of heart failure and hypertension and decreases ECF volume - hypokalmeia, gout + metabolic alkalosis

Question 3

Probenecid

Answer 3

Inhibits uric acid reabsorption, used in combination with diuretics to prevent gout formation

Question 4

Hydorchlorothiazide

Answer 4

Thiazide diuretic - block the Na/Cl co-transporter in the thick ascending limb and distal tubules through binding to the Cl- site, weak carbonic anhydrase inhibitors and slight vasodilator effects
Hypokalaemia + metabolic alkalosis

Question 5

Bendroflumethiazide

Answer 5

Thiazide diuretic - block the Na/Cl co-transporter in the thick ascending limb and distal tubules through binding to the Cl- site, weak carbonic anhydrase inhibitors and slight vasodilator effects
Hypokalemia + metabolic alkalosis

Question 6

Amiloride

Answer 6

Potassium sparing diuretic - blocks the apical Na channel in the distal tubule
Weak diuretic effect but reduces potassium loss

Question 7

Trimeterene

Answer 7

Potassium sparing diuretic - blocks the apical Na channel in the distal tubule
Weak diuretic but reduces potassium loss

Question 8

Spironolactone

Answer 8

Potassium sparing diuretic - Aldosterone antagonist, prevents its translocation to the nucleus
Effect only seen when distal tubule under the influence of aldosterone however
Converted in Conrenone in the liver - Potassium coneronate can also act as a diuretic

Question 9

Acetazolamide

Answer 9

Carbonic anhydrase inhibitor therefore inhibits NaHCO3 reabsorption in the proximal and distal tubules by decreasing the availability of H+
Causes a rise in urine pH as HCO3 content increased and increased K+ loss in the distal tubule and potential metabolic acidosis
Also used in Glaucoma treatment

Question 10

Mannitol

Answer 10

Osmotic diuretic - ‘Drags’ water along with its secretion, filtered at the glomerulus and to reabsorbed, increase urine volume and decrease Na reabsorption in the proximal T
Cerebral oedema to reduce intracranial pressure

Question 11

Adenosine

Answer 11

Endogenous Renin inhibitor

Acts on A1 receptors in the juxtaglomerular apparatus decreasing CAMP and therefore decreasing Renin release

Question 12

Atrial Naturetic peptide

Answer 12

Endogenous Renin inhibitor
Released from the heart as a result of increased stretch following rise in circulating volume, inhibitors renin through C-GMP on the juxtaglomerular cells

Question 13

Captoril

Answer 13

ACE inhibitor used in heart failure and hypertension

Question 14

Enalopril

Answer 14

ACE inhibitor used in heart failure and hypertension

Question 15

Saralasin

Answer 15

Angiotensin II partial agonist, only shows therapeutic effects when angiotensin concentration high enough to compete, will mimic the action of angiotensin when conc is low!
IV adminstration

Question 16

Losartan

Answer 16

Angiotensin II receptor 1 antagonist

Question 17

Aliskiren

Answer 17

Renin inhibitor - binds to the angiotensin site preventing its activation