05.20 - Drugs and Renal Fxn (Sweatman)

Question 1

2 peptide-like drugs

Answer 1

beta-lactams, ACEi’s

Question 1

Though inward conductance is greater than outward, K efflux does not occur b/c

Answer 1

Vm is more positive than EK

Question 2

What provides driving force for K excretion in DT epithelial cells

Answer 2

Na absorption –> Depolarizes membrane

Question 3

Tx for hyperkalemia is required if

Answer 3

EKG changes

Question 4

What mediates reabsorption of peptide-like drugs

Answer 4

Peptide Transporters (PEPT1, PEPT2)

Question 5

Capacity rate limited

Answer 5

Extraction ratio is limited by the reversible binding of the drug to plasma proteins or its location in RBCs

Question 5

NSAID use in CKD will cause

Answer 5

Acute reductions in renal bloodflow and GFR

Question 6

PGI2/PGE2 preserve GFR by antagonizing arteriolar vasoconstrictors and

Answer 6

blunting mesangial and podocyte contraction

Question 7

Drugs that antagonize ___ increase risk of AKI when NSAID is administered

Answer 7

Drugs that antagonize RAAS

Question 8

Effect of PG’s on RAAS

Answer 8

Stimulate Renin secretion –> Enhance Na retention and K secretion

Question 8

Effect of PG’s on ADH

Answer 8

Inhibit cAMP synthesis and oppose ADH –> Water excretion

Question 10

What provides driving force for reabsorptio of drugs and drug metabolites

Answer 10

Extensive reabsorption of filtered water

Question 11

Why doesn’t K efflux thru ROMK at physiological intracellular Mg

Answer 11

Intracellular Mg binds ROMK and blocks K efflux

Question 12

T/F: PGs are a primary regulator of renal function

Answer 12

False, minimal importance in kidney of health individuals with normal volume status

Question 12

What can be used to remove K+ in patients with renal failure

Answer 12

Dialysis

Question 12

Low magnesium can exacerbate ___ by ___

Answer 12

K wasting by incr K secretion in DT

Question 13

Most common cause of drug-induced hypokalemia

Answer 13

Anti-infective agents

Question 14

Effect of PGI2 and PGE2 in kidney

Answer 14

Vasodilation of interlobular arteries, afferent and efferent arterioles, and glomeruli

Question 14

Effects of PG’s on LOH and Distal Nephron

Answer 14

(1) Incr renal Na excretion, decr medullary tonicity; (2) Stimulate Renin secretion; (3) Inhibit cAMP and oppose ADH

Question 14

Acute NSAID toxicity is manifest in terms of

Answer 14

Tubular Epithelial Necrosis secondary to altered renal hemodynamics

Question 15

Anti-infective agents commonly cause what electrolyte abnormality

Answer 15

HypoKalemia

Question 16

Diureti-induced hypokalemia is associated with

Answer 16

Mild-Moderated Metabolic Alkalosis

Question 18

2 commonly used formulas that estimate GFR

Answer 18

Cockroft-Gault; MDRD

Question 18

Effect of PGE2 on cellular transport of NaCl

Answer 18

Decreases cellular transport of NaCl –> Increase Na excretion and decr in medullary tonicity

Question 20

Kidney PGs have their major role in

Answer 20

preservation of renal fxn when pathologic states supervene and compromise physiologic kidney processes

Question 21

3 steps in hyperkalemia tx

Answer 21

(1) Calcium Gluconate, (2) Shift to intracellular, (3) Removal of excess K+

Question 23

Risk of NSAID-associated AKI in health persons

Answer 23

Low, b/c PG production is low in healthy persons

Question 24

Second most common cause of drug-induced hypokalemia

Answer 24

Diuretics

Question 26

Net effect of PG actions on LOH and Distal Nephron is that chronic NSAID consumption can lead to

Answer 26

a mild, dose-dependent increase in BP

Question 28

Tubular secretion occurs primarily in

Answer 28

pT

Question 28

GFR \> ___ is normal

Answer 28

80

Question 29

At physiological intracellular Mg concentration, ROMK conducts K in which direction

Answer 29

Inward

Question 30

Perfusion rate limited

Answer 30

extraction ratio is not limited to the unbound fraction of drug

Question 30

COX-2 inhibitor effects on kidneys

Answer 30

equivalent to other classes with respect to their nephrogenic potential

Question 31

NSAIDs are also associated with interstitial nephritis that is thought to be result of

Answer 31

Allergic reaction

Question 32

GFR \< ___ is severe renal impairment

Answer 32

30

Question 34

3 conditions with increased prevalence that are exacerbated by GFR

Answer 34

HTN, CHF, Renal insufficiency

Question 35

Organic anion and cation transporter systems, w/ overlapping specificities, allow potential for

Answer 35

Drug-Drug interactions

Question 35

How does insulin lower hyperkalemia

Answer 35

Stimulates Na/H exchange --\> Na in --\> Stimulates Na/K --\> Uptake of K into cell

Question 36

PG production is increased in ___ disease

Answer 36

chronic kidney disease

Question 37

Leading causes of drug-induced hyperkalemia

Answer 37

Aldosterone antagonist/k-sparing agents and ACEi/ARB

Question 39

\_\_\_ locally mediate effects of both systemic and locally produced vasoconstrictor hormones

Answer 39

Eicosanoids

Question 40

K secretion in DT is under regulation of

Answer 40

intracellular Mg

Question 42

3 effects of Calcium in HyperKalemia

Answer 42

(1) Less neg resting Vm; (2) Shift upwards and right of Vm x Vmax curve; (3) Reverses depressed conduction

Question 44

Action of Albuterol tx of Hyperkalemia

Answer 44

Activates Na/K --\> Na leaving forces K in

Question 46

2 "situations" when PG's play role in preserving renal fxn

Answer 46

True intravascular volume depletion; Effective decrease in renal blood flow

Question 47

Surge in catecholamines is often associated with what electrolyte change

Answer 47

Hypokalemia

Question 48

With no Mg and normal K concentrations, the chemical gradient drives K in which direction?

Answer 48

Outward

Question 49

2 drugs commonly used to tx Hyperkalemia

Answer 49

B2 agonist (Albuterol) and Insulin

Question 50

Insulin stimulates what transporter

Answer 50

Na/H exchange (Na in, H out)

Question 51

PGI2/PGE2 antagonize

Answer 51

local effects (vasoconstriction) of circulating Ang2, Endothelin, Vasopressin, and Catecholamines (that would normally maintain systemic pressure at expense of renal circulation)

Question 52

What aspect of tubular secretion allows for drug-drug interactions

Answer 52

Transporters with overlapping substrae specificities