Nephrology

Question 1

Oxybutynin

Answer 1

Muscarinic antagonist , mainly act on bladder(M3)

Question 2

Bethenacol

Answer 2

Muscarinic agonist, mainly act on bladder (M3)

Question 3

alpha blockers for overflow incontinence

Answer 3

mainly act on the bladder sphincter (a1)

Question 4

Bartter syndrome

Answer 4

defect in NA-K-Cl transporter in thick ascending loop —> decreased reabsorption of those ions and abolishment of the positive lumen potential created by potassium transport —> decreased calcium and magnesium transport

• Also abolishes the hypertonicity of the renal medulla leading to decreased water reabsoprtion —>hypovolemia
• Increased sodium to the distal tubule leads to compensatory mechanism which increases potassium loss —> hypokalemia which the alpha intercalated cells try to correct at the expense of hydrogen ion loss —>metabolic alkalosis

Question 5

Gitleman syndrome

Answer 5

defect in Na-cl transporter in the distal tubule

Question 6

Hendleson-Hasselbach equation

Answer 6

pH=6.1 + log [HCO3-] / [.03 x PaCO2]

Question 7

Amiloride

Answer 7

potassium-sparing diuretic

Question 8

Hyperkalemia due to non-selective beta blockers

Answer 8

due to action of beta 2 blocking which inhibits the formation of cAMP leading to decreased Na-K pump activity and increased extracellular potassium.
- Especially harmful in patients with failing kidneys

Question 9

NSAIDS

Answer 9

due to inhibition of local prostaglandin synthesis, reducing renin and aldosterone secretion.

Question 10

Hepatorenal syndrome

Answer 10

liver cirrhosis —> increased NO production due to portal HTN —> systemic vasodilation and hypotension —> renal hypoperfusion —> activation of RAAS —> water and sodium retention and volume overload
- Nonresponsive to volume replacement.