diuretics

Question 1

what are diuretics commonly used for

Answer 1

HTN

heart failure

Question 2

diuretics sit of action

Answer 2

upstream of the collecting duct. =hyponatremia, hypokalemia and metabolic alkalosis.

in collecting duct result in hyperkalemia and metabolic acidosis

Question 3

what class of drugs is Acetazolamide

Answer 3

prototype of a class of sulfonamide drugs that- avidly bind to the enzyme carbonic anhydrase

Question 4

what type of inhibition does acetazolamide produce

Answer 4

noncompetitive inhibition of the enzyme activity

Question 5

in normal circumstances- what is the carbonic anhydrase enzyme responsible for in the renal tubule

Answer 5

NA+/H+ exchanger- allowing absorption of NA in exchange for secretion of H+ into the renal tubule

Question 6

in normal circumstances what happens to bicarb and H in the proximal renal tubule

Answer 6

they combine to form carbonic acid

Question 7

what does the carbonic anhydrase enzyme do to H2C03

Answer 7

catalyzes it into C02 and water

Question 8

c02 diffuses readily into the tubular cells where cytoplasmic carbonic anhydrase catalyses the reverse reaction leading to

Answer 8

Hc03- and absorption of HC03

Question 9

carbonic anhydrase inhibitors do what

Answer 9

inhibit carbonic anhydrase in the proximal renal tubule by this class of diuretics results in decreased reabsorption of Na, HC03, an water

Question 10

who do we adjust acetazolamide dosing for

Answer 10

renal patients and the elderly

Question 11

acetazolamide blocks what in the proximal tubule

Answer 11

membrane bound and cytoplasmic carbonic anhydrase in the proximal tubule-preventing na and HC03 absorption

Question 12

***acetazolamide acid base imbalance

Answer 12

alkaline urine and metabolic acidosis

Question 13

***acetazolamide increase in delivery of sodium to the distal tubules leads to

Answer 13

k loss

Question 14

how is acetazolamide effective in the treatment of glaucoma

Answer 14

high concentration of carbonic anhydrase enzyme in the ciliary processes, inhibition of the enzyme activity by acetazolamide results in decreased formation of aqueous humor and consequently a decrease in intraocular pressure.

Question 15

acetazolamide what does it do to ICP

Answer 15

cerebral spinal fluid formation is inhibited by acetazolamide- treatment for idiopathic intracranial hypertension.

Question 16

if acetazolamide does not decrease ICP-what treatment should occur

Answer 16

placement of ventriculoperitoneal shunt to reduce elevated ICP

Question 17

acetazolamide produces metabolic acidosis- what might it do to the respiratory drive

Answer 17

it may stimulate the respiratory drive in patients who are hyperventilating in a compensatory response to respiratory alkalosis- such as in altitude sickness

Question 18

hypoxia at high altitudes is counteracted by hyperventilating which results in respiratory alkalosis resulting in ventilation depression. what can we give to reverse this hypoventilaiton

Answer 18

acetazolamide induced metabolic acidosis can reverse hypoventilation.

Question 19

***The loss of bicarbonate ions necessary to buffer carbon dioxide may result in the exacerbation of respiratory acidosis in patients with COPD leading to CNS depression

Answer 19

.

Question 20

Side Effects of Acetazolamide:

Answer 20

Fatigue
Decreased appetite
Depression
Paresthesia (could be secondary to metabolic acidosis)

Question 21

LOOP DIURETICS

Answer 21

Furosemide, Torasemide, Azosemide, Bumetanide and Ethacrynic acid

Question 22

loop diuretics Inhibit reabsorption of

Answer 22

NA, K, CL

Question 23

where do loop diuretics work in the nephron

Answer 23

thick ascending limb of the loop of henle

Question 24

the thick ascending limb of the loop of henle- is impermeable to water and accounts for the reabsorption of how much filtered na

Answer 24

20-30%

Question 25

Diuretics in general and loop diuretics in particular are 1st line therapy for what patients

Answer 25

patients with fluid retention resulting form heart failure

Question 26

what is a common side effect of all loop diuretics

Answer 26

ototoxicity

Question 27

why dont we use ethacrynic acid

Answer 27

no longer in use due to increased incidence of ototoxicity and nausea and vomiting

Question 28

furosemide % protein bound to albumin

Answer 28

90%

Question 29

furosemide PO absorption varies 10-100% with average bioavailability of what %

Answer 29

50%

Question 30

glomerular filtration and renal tubular secretion account for what percent of furosemide excretion

Answer 30

50-60%

Question 31

furosemide remaining 40-50% is

Answer 31

conjugated to glucuronide in the kidneys

Question 32

elimination furosemide half life

Answer 32

1-2 hours resulting in short duration of action

Question 33

furosemide rapid onset producing diuresis is within

Answer 33

5-10 minutes of administration

Question 34

peak effect of furosemide

Answer 34

30 minutes

Question 35

duration of furosemide

Answer 35

2-6hrs

Question 36

normal renal function furomsedie dose

Answer 36

40mgIV

Question 37

what happens to the furosemide dose in renal insufficiency patients

Answer 37

increase dose

Question 38

max diuresis can be achieved with IV bolus of furosemide- what mg? push slow d/t?

Answer 38

160-200mg | give slowly to avoid tinnitus

Question 39

will doses larger than 200 of furosemide increase natriuresis

Answer 39

no

Question 40

bumetanide bioavailability

Answer 40

80-100% after PO administration

Question 41

bumetanide administration routes

Answer 41

IV, PO, IM

Question 42

bumetanide how many more times potent than furosemide

Answer 42

40 x more potent

Question 43

torasemide metabolism

Answer 43

mostly by liver

Question 44

patients with liver failure receiving torsemide will have an increase drug delivery to which organ

Answer 44

kidneys

Question 45

torasemide is how much more potent as furosemide

Answer 45

2x

Question 46

torsemide duration of action

Answer 46

longer duration of action with plasma 1/2 life 3-4 hours thus once a day dosing

Question 47

comparing furosemide to torsemide which is better for heart failure

Answer 47

Treatment with torasemide was found to decrease readmissions related to heart failure when compared to furosemide.1

Question 48

what diuretic lowers calcium.

Answer 48

In the presence of symptomatic hypercalcemia, furosemide may be used to lower the plasma concentration of calcium by stimulating urine output

Question 49

what combination decreases ICP most effectively.

Answer 49

A combination of furosemide and mannitol is more effective in decreasing ICP than either drug alone

Question 50

Side Effects: loop diuretics

Answer 50

Normally manifest as abnormalities of fluid and electrolyte balance Hypokalemia; Digitalis Toxicity Hyperuricemia: rarely clinically significant Potential hyperglycemia not as likely as thiazides

Question 51

braking phenomenon

Answer 51

Acute or chronic treatment of patients with diuretics, including loop diuretics, may result in tolerance to the diuretic effect

Question 52

Side Effects: look diuretics relating to aminoglycosides

Answer 52

enhances he possible nephrotoxic effects of these antibotics

Question 53

side effects - loop diuretics and non depolarizing neuromuscular blockers

Answer 53

potentiate non depolarizing neuromuscular blockade

Question 54

loop diuretics cephalosporin

Answer 54

Cephalosporin nephrotoxicity may also be increased by furosemide

Question 55

furosemide cross sensitivity

Answer 55

Cross sensitivity may exist when allergic to sulfonamides

Question 56

furosemide and lithium reaction

Answer 56

An acute increase in lithium plasma concentrations with IV administration of furosemide in perioperative period

Question 57

furosemide- ototoxicity

Answer 57

Ototoxicity is either transient or permanent; is a rare reaction and is dose dependent.

Question 58

HCTZ and thiazide drugs

Answer 58

chlorthalidone and indapamide

Question 59

thiazide diuretics what are they used for

Answer 59

most often used for long term treatment of hypertension in which the combination of diuresis, natriuresis, and vasodilation are synergistic

Question 60

what is the second most frequently prescribed antihypertensive med with other antihypertensives

Answer 60

HCTZ

Question 61

thiazide diuretics may be used to mobilize edema associated with what three organ dysfunction

Answer 61

renal hepatic cardiac dysfunction

Question 62

thiazide diuretics less common use is

Answer 62

management of DI and hypercalcemia

Question 63

are thiazide diuretics readily absorbed PO?

Answer 63

yes

Question 64

HCTZ bioavailability and protein bound

Answer 64

60-70% bioavailability extensively protein bound.

Question 65

thiazides are eliminated unchanged by the kidneys- except indapamide which is metabolized how

Answer 65

by the liver

Question 66

thiazide diuretics half life

Answer 66

8-12 hours

Question 67

thiazide diuretic with the longest elimination half life of 50-60 hrs

Answer 67

chlorthalidone

Question 68

how effective is thiazide diuretics in renal patients

Answer 68

markedly decrease effectiveness

Question 69

with the exception of metolazone. thiazide diuretics have what effect on severe renal insufficiency

Answer 69

ineffective in renal insufficiency- use loop diuretics

Question 70

electrolyte excretion with thiazide diuretics

Answer 70

kaliuresis may accompany sodium and magnesium ion loss

Question 71

with the loss of potassium and magnesium- thiazide diuretics may present with cardiac

Answer 71

dysrhythmias

Question 72

side effects of thiazide diuretics

Answer 72

Hypercalcemia especially if on supplements Potentiate NDMB by producing hypokalemia Effectiveness is decreased when patient is taking NSAIDS Potentiates lithium toxicity May cause glucose intolerance and aggravate glucose control in diabetics May aggravate hyperlipidemia Patients with sulfa allergy may demonstrate cross-reactivity to these classes of diuretics

Question 73

preop orthostatic hypotension suggest

Answer 73

low circulation of fluid volume

Question 74

what is the only osmotic diuretic in use

Answer 74

mannitol

Question 75

where does mannitol work

Answer 75

proximal real tubule and loop of henle are the principle site of action

Question 76

how is osmotic diuretics cleared

Answer 76

from plasma by glomerular filtration

Question 77

mannitol is a scavenger of free radicals which may prevent?

Answer 77

Is a scavenger of oxygen-free radicals, which may prevent cellular injury

Question 78

Mannitol Clinical Uses:

Answer 78

Primarily used in the acute management of elevated ICP and in treatment of glaucoma Exerts effect within 10-15 minutes Peak effect at 30-45 minutes Duration of 6 hours

Question 79

Mannitol Clinical Uses:

Answer 79

Effect on ICP is dose dependent: larger dose may last longer Large doses up to 2g/kg and repeated administration can result in metabolic derangements Intact blood-brain barrier is necessary for cerebral effects of Mannitol Non-intact blood-brain barrier may enter the brain, drawing fluid with it and causing worsening cerebral edema Rebound increase in ICP may occur following mannitol use

Question 80

in the setting of acute tubular necrosis- what can mannitol be used to prevent

Answer 80

Can be used to prevent perioperative kidney failure in the setting of acute tubular necrosis

Question 81

patients with LV dysfunction may not tolerated mannitol leading to

Answer 81

pulmonary edema

Question 82

what medication is a better choice to treat high ICP in patients with LV dysfunction

Answer 82

furosemide

Question 83

in renal dysfunction mannitol is not filtered and will cause

Answer 83

In renal dysfunction mannitol is not filtered and will cause increase in the intravascular volume

Question 84

Prolonged use of Mannitol may cause:

Answer 84

Hypovolemia Electrolyte disturbances Hypokalemic hypochloremic alkalosis Plasma hyperosmolarity due to excessive excretion of water and Na+

Question 85

NOT INCLUDED_potassium sparing diuretics

Answer 85

potassium sparing diuretics