Diuretics

Question 1

Forces Favoring Filtration

Answer 1

Glomerular hydrostatic pressure 60

Bowman’s capsule colloid osmotic pressure 0

Question 2

Forces Opposing Filtration

Answer 2

Bowman’s capsule hydrostatic pressure 18

Glomerular capillary colloid osmotic pressure 32

Question 3

GFR is normally preserved by

Answer 3

maintaining a constant RBF over a range of systemic blood pressures with MAP 50 to 150 mmHg

Question 4

these patients have a higher GFR when RBF is constant

Answer 4

hypertensive

Question 5

describe the Myogenic Autoregulation of RBF and GFR

Answer 5

↑ arterial pressure stretches afferent arteriolar wall then a reflex constriction occurs
↓ Arterial pressure causes arteriolar dilation

Question 6

describe Tubuloglomerular Autoregulation of RBF and GFR

Answer 6

↓ RBF = ↓ GFR which results in afferent arteriolar dilation which increase GFR and RBF and restore filtration
Renin released = angiotensin II = ↑ GFR

Question 7

what is urine made of?

Answer 7

electorlytes
waste products
metabolites

Question 8

Urine excretion is equal to

Answer 8

Filtration rate – reabsorption rate + secretion rate

Question 9

Diuretic Uses 6

Answer 9

Reduce HTN (decrease intravascular fld vol.)
Treat pulmonary and peripheral edema
Electrolyte and pH corrections (hyperkalemia)
Reduce ICP, brain bulk
Prevent ARF due to ischemic insult
Drug clearance

Question 10

how are diuretics classified?

Answer 10

Site of action on renal tubules

How they excrete solute

Question 11

Main classifications diuretics?

Answer 11

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

Question 12

4 Loop Diuretics

Answer 12

Furosemide (Lasix)
Torsemide (Demadex)
Bumetanide (Bumex)
Ethacrynic Acid (Edecrin) no longer avail.

Question 13

moa loop diuretics

Answer 13

Inhibit reabsorption of NaCl in

ascending loop

Question 14

Most effective diuretic class

Answer 14

Loop Diuretics

Question 15

what are Loop Diuretics used for?

Answer 15

Used more to decrease intravascular fluid volume and for rapid excretion of drugs

Question 16

Do loop diuretics increase GFR?

Answer 16

nope

Question 17

loop diuretics Stimulates production of prostaglandins which produces

Answer 17

Vasodilation

Increased RBF

Question 18

Loop Diuretics (Lasix) indications 5

Answer 18

Rapid intravascular fluid removal 
Hyperkalemia treatment
Acute pulmonary edema
Kidney stone extraction, lithotripsy
Reduce intracranial pressure

Question 19

what can be used in combination with mannitol and why?

Answer 19

Systemic diuresis and ↓ CSF production to reduce ICP

Question 20

hypokalemia is Loop Diuretics Concern, which causes

Answer 20

Shown to deplete myocardial K+ stores
Potential digitalis toxicity
Enhanced NMB effects

Question 21

what does lasix do in large doses 1-4 mg/kg in regards to NMB

Answer 21

inhibits phosphodiesterase, increasing cAMP (same as azathioprine, Imuran) – makes patients resistant to NMB

Question 22

what does lasix <1mg/kg do in regards to NMB with small doses?

Answer 22

decreased cAMP production – makes patients sensitive to NMB.

Question 23

big concern of loop diuretics we have known since nursing school

Answer 23

ototoxic

Question 24

loop diuretics cause many imbalances, what should you be ready for?

Answer 24

Potassium replacement may be indicated
Cardiac dysrhythmias can occur
Fluid volume replacement may be indicated
Orthostatic hypotension
Hemoconcentration, (increased Hct, BUN)
Mild hyperglycemia

Question 25

thiazide diuretics typically end with

Answer 25

thiazide

Question 26

MOA thiazide diuretics

Answer 26

Inhibits reabsorption of NaCl in loop, proximal and distal tubules

Question 27

thiazide diuretics are used in Treatment for

Answer 27

Hypertension Edema from CHF Renal failure

Question 28

how do thiazides ↓ HTN by diuresis, vasodilation

Answer 28

↓ SNS in peripheral vascular smooth muscle due to ↓ total body Na+ stores

Question 29

Thiazide Diuretics Concerns

Answer 29

↓ K+, ↓ Mg+, ↓ Cl-, hypochloremic metabolic alkalosis Hyperglycemia, Hyperuricemia

Question 30

Hypokalemia can further lead to

Answer 30

``` Increased potential for digitalis toxicity Cardiac dysrhythmias Muscle weakness Neuropathy Potentiation of NMBA ```

Question 31

one different implication when using thiazide diuretics?

Answer 31

gouty arthritis

Question 32

Osmotic Diuretics

Answer 32

Mannitol | Urea

Question 33

MOA of osmotic diuretics?

Answer 33

Osmotic diuresis Increased plasma osmolarity Proximal convoluted tubule,Loop of Henle Does not alter GFR

Question 34

osmotic diuretics are Large molecular weight molecules which means?

Answer 34

Filtered but is too large to reabsorb back. | Acute expansion of intravascular fluid volume

Question 35

these are used in craniotomies to reduce brain bulk?

Answer 35

Osmotic Diuretics

Question 36

Osmotic Diuretic Side Effects?

Answer 36

``` Increased intravascular fluid volume until filtered Rebound HTN in non-intact BBB Pulmonary edema Can exacerbate CHF Electrolyte disturbances ```

Question 37

3 uses for mannitol?

Answer 37

Reduction of intracranial pressure and brain mass Reduction of high intraocular pressure when unable to lower pressure by any other mechanism Urinary excretion of toxic materials

Question 38

Allows secretion of Na+ and CL- | Used in combination with thiazide diuretics

Answer 38

Aldosterone Antagonist [spirinolactone]

Question 39

Aldosterone Antagonist are used for what type of patients?

Answer 39

CHF Liver Cirrhosis **Both conditions lead to increased aldosterone

Question 40

side effect of spirinolactone?

Answer 40

hyperkalemia - aldosterone gets rid of K and this drug blocks aldosterone

Question 41

moa k sparing diuretics

Answer 41

Spares potassium independent of Aldosterone Weak diuretic effects Distal tubules and collecting ducts

Question 42

Triamaterene, Amiloride [k sparing] cause | Increased excretion

Answer 42

Na+, Cl-, Bicarb NOT K --- Used in combination with loop diuretics to limit potassium losses in the distal tubule

Question 43

Potassium Sparing Diuretics side effect

Answer 43

hyperkalemia

Question 44

Use k sparing cautiously with

Answer 44

in patients at risk for hyperkalemia | Patients using ACEI and NSAIDs (both cause increased K+)

Question 45

Works in proximal tubules | Inhibiting CA blocks Na+bicarb & causes diuresis

Answer 45

Carbonic Anhydrase Inhibitors (CAI

Question 46

Carbonic Anhydrase inhibitors used in

Answer 46

Used in glaucoma to reduce intraocular pressure by decreasing aqueous humor

Question 47

Carbonic Anhydrase Inhibitors (CAI) Side Effects

Answer 47

Hyperchloremic metabolic acidosis Drowsiness Paresthesia Renal calculi

Question 48

Vasopressin Receptor Antagonist Only U.S. FDA approved drug

Answer 48

Tolvaptan

Question 49

Vasopressin Receptor Antagonist specifically used for

Answer 49

SIADH, CHF, Liver cirrhosis | Treats hyponatremia assoc. with normal volume status

Question 50

MOA of Vasopressin Receptor Antagonist

Answer 50

Renal collecting duct V2 receptors

Question 51

D1 receptors in proximal renal tubule & loop of Henle cause

Answer 51

Increased renal blood flow Increased glomerular filtration rate (GFR) Natriuresis

Question 52

2 things that activate D1 receptors

Answer 52

Dopamine & Fenoldopam

Question 53

what dose of dopamine works to activate D1

Answer 53

low dose only (1-3 mcg/kg/min) larger doses = sns stimulation

Question 54

natriuretic peptides Block basal Na-K-ATPase channel which causes

Answer 54

Vasodilation & venous dilator = decrease venous return = decrease cardiac output Sodium excretion

Question 55

Produced in atria, ventricles, and renal system Stimulated by atrial and ventricular distention Increased wall stress, volume overload, and HTN during heart failure

Answer 55

Atrial natriuretic peptides(ANP)&Brain natriuretic peptides(BNP)

Question 56

``` Only U.S. FDA approved drug in natriuretic peptide class Hypotension is primary side effect ```

Answer 56

Nesiritide (Natrecor): IV infusion with short half life (18 min)

Question 57

metalloproteinase breaks down BNP and ANP

Answer 57

Neprilysin (NEP) Antagonist

Question 58

NEP antagonists cause an increase

Answer 58

in circulating levels of both BNP & ANP “indirectly” causing natriuresis

Question 59

Neprilysin (NEP) Antagonist used in combo with

Answer 59

ACEI to achieve both natriuresis and reduction in BP for CHF patients

Question 60

Entresto: sacubritril/valsartan side effects

Answer 60

Hypotension and hyperkalemia