The Kidney and Drugs

Question 1

Define “clearance”

Answer 1

A measure of the rate at which a substance is removed from the blood

Question 2

Define “steady-state”

Answer 2

Corresponds to the state of equilibrium obtained at the end of a certain number of administrations

Question 3

Define “xenobiotics”

Answer 3

A chemical compound foreign to a given biological system

Question 4

Give two examples of drugs which can be Ototoxic

Answer 4

Aminoglycosides

Loop diuretics

Question 5

Define “diuretic”

Answer 5

Any substance which promotes water loss for control of disease in other tissues

Question 6

What pH do the kidneys have?

Answer 6

5 - 7

Question 7

The PCT reabsorption how much of all that is filtered by the Glomerulus?

Answer 7

2/3rds of filtrate

Question 8

What is the component basis of Alkaline and Acidic diets?

Answer 8

Alkaline - vegetable based

Acidic - protein based

Question 9

What pH does the stomach have?

Answer 9

3

Question 10

Things below what Kd size can pass through the ultrafiltration barrier?

Answer 10

68

Question 11

Some drugs may be small enough to pass through the ultrafiltration barrier, but still may not, why?

Answer 11

Some drugs i.e. warfarin may bind to plasma proteins such as albumin and therefore will not be cleared by the system

Question 12

Give examples of things which are secreted out of PCT

Answer 12

Organic anions (negatively charged) and organic cations (positively charged)

Question 13

Give examples of anionic drugs which are secreted out of the PCT

Answer 13

Penicillin, cephalosporins, salicylates, diuretics

Question 14

Give examples of cationic drugs which are secreted out of the PCT

Answer 14

Trimethoprim, cimetidine, quinidine

Question 15

Give an example of a lipid soluble drug which is completely reabsorbed by the kidneys

Answer 15

Diazepam

Question 16

Give an example of a basic drug

Answer 16

Amphetamine

Question 17

Give an example of an acidic drug

Answer 17

Aspirin

Question 18

Define “half-life”

Answer 18

The time necessary to halve the plasma concentration of a drug

Question 19

Why do drugs such as Aminoglycosides / Loop diuretics cause otoxocity?

Answer 19

They cause reduced clearance due to nephro-toxicity

Question 20

Which part of the kidneys do Carbonic anhydrase inhibitors work on?

Answer 20

Proximal convoluted tubule

Question 21

What is the normal role of Carbonic anhydrase in the kidneys?

Answer 21

Facilitate reabsorption of bicarbonate, sodium, and chloride into the kidneys from filtrate

Question 22

What is the mechanism of action of Carbonic anhydrase inhibitors?

Answer 22

Inhibition leads to excretion of bicarbonate, sodium and chloride into the urine along with water, thereby causing diuresis and lowering blood pressure

Question 23

Carbonic anydrase causes blood pH to become acidic - what is a compensatory mechanism exhibited by the patient?

Answer 23

Hyperventilation (Kussmaul breathing)

Question 24

Give an example of 2 Carbonic anyhdrase inhibitors

Answer 24

Acetozolamide

Methazolamide

Question 25

Where do Loop diuretics have their mechanism of action in the kidneys?

Answer 25

Ascending Loop of Henle

Question 26

What transporter do Loop diuretics inhibit? What ions do they inhibit resorption of?

Answer 26

Na+/K+/2Cl- co-transporter, inhibiting Na and Cl reabsorption

Question 27

Give 2 examples of Loop diuretics

Answer 27

Furosemide

Bumetanide

Question 28

Where do Thiazides act on in the kidneys?

Answer 28

Distal Convoluted Tubule

Question 29

What transporter do Thiazides inhibit? What ions do they inhibit resorption of?

Answer 29

Na+/Cl- symporter, inhibiting Na and Cl reabsorption

Question 30

Which site of the kidneys do ADH work? What channels?

Answer 30

Collecting tubule / duct, Aquaporins (H2O channels)

Question 31

Give one example of a thiazide drug

Answer 31

Bendroflumethizide

Question 32

Where does the osmotic diuretic D-Mannitol work in the kidneys?

Answer 32

Ascending / Descending Loop of Henle

Question 33

Where do K+ sparing diuretics work in the kidneys?

Answer 33

Collecting ducts

Question 34

Give two examples of K+ sparing diuretic drugs

Answer 34

Amiloride

Spirinolactone

Question 35

How do K+ sparing diuretics work?

Answer 35

Aldosterone receptor antagonist, increasing NaCl excretion and decreasing K excretion