Ex5 Diuretics

Question 1

Acetazolamide

Answer 1

Carbonic anhydrase inhibitor

Question 2

MOA Acetazolamide

Answer 2

inhibits carbonic anhydrase in proximal tubule

Question 3

Clinical uses Acetazolamide

Answer 3

Diuresis
Chronic open-angle glaucoma
Metabolic Alkalosis

Question 4

Acetazolamide clearance

Answer 4

via kidneys

Question 5

Acetazolamide onset, peak, duration

Answer 5

onset/peak/duration - fast

duration – 4hours

Question 6

How should Acetazolamide be adjusted for renal patients?

Answer 6

CrCl <10 = avoid

CrCl 10-50 = one dose will correct alkalosis

Question 7

Acetazolamide AEs

Answer 7

Metabolic Acidosis (be careful to OVERcorrect alkalosis)
Hyperchloremia
Hypotension
Hypokalemia/natremia/phosphatemia/magnesemia/calcemia

Question 8

Avoid Acetazolamide with

Answer 8

NS - could worsen hyperchloremic acidosis

Question 9

Loop diuretics

Answer 9

ethacrynic acid
furosemide
bumetadine

Question 10

Clinical uses of loop diuretics

Answer 10

diuresis (heart/liver/renal failure)
HTN
acute pulm edema
hyperkalemia
hyperphosphatemia, hypercalcemia

Question 11

Ethacrynic Acid IV Onset, Peak, Duration

Answer 11

Fast
O: 5min
P: 15min
D: 2h

Question 12

Severe sulfa allergy in patient who needs diuresis – tx?

Answer 12

Ethacrynic Acid

Question 13

Fast rates of IVP loop diuretics may cause

Answer 13

ototoxicity (limit to 10mg/min)

Question 14

Most diuretics are excreted via

Answer 14

kidneys

Question 15

Dialyzable diuretics

Answer 15

Acetazolamide (HD: 20-50%)
Ethacrynic Acid: minimal
Mannitol (14% with 6h session)
Triamterene: Yes

Question 16

Renal impairment - how to dose diuretics?

Answer 16

MUCH larger dose (i.e. Furosemide=100mg)

Question 17

Torsemide careful with?

Answer 17

Duration: 6-8h; only PO

Question 18

Highest risk of ototoxicity

Answer 18

Ethacrynic Acid

Question 19

Braking Phenomenom

Answer 19

Loop diuretic tolerance

-hypertrophy in renal tubule/reabsorbs what was blocked

Question 20

Management of loop diuretic tolerance

Answer 20

• thiazide diuretics
• continuous infusion (vs. IVpush)
• increased dose

Question 21

Loop Diuretic Equivalent dosing: Bumex 1mg IV = Furosemide _____IV

Answer 21

20mg

Question 22

Loop Diuretic Equivalent dosing: Bumex 1mg IV = Ethacrynic Acid _____IV

Answer 22

50mg

Question 23

Loop Diuretic Equivalent dosing: Bumex 1mg IV = Bumex _____PO

Answer 23

1mg

Question 24

Loop Diuretic Equivalent dosing: Bumex 1mg IV = Torsemide _____PO

Answer 24

20mg

Question 25

Loop Diuretic Equivalent dosing: Furosemide 20mg IV = Furosemide _____PO

Answer 25

40mg

Question 26

Loop Diuretic Equivalent dosing: Ethacrynic Acid 50 mg IV = Ethacrynic Acid _____PO

Answer 26

50mg

Question 27

Loop/thiazide diuretics effect on anesthesia

Answer 27

Electrolyte imbalance (esp hypokalemia/hypocalcemia) may prolong NMB

Question 28

Thiazide Diuretics

Answer 28

Chlorothiazide Metolazone Hydrochlorothiazide

Question 29

Best diuretic to use for targeting volume

Answer 29

Loop Diuretics

Question 30

Hypernatremic Hypervolemic - in addition to loop diuretics, what tx should be added?

Answer 30

Thiazide diuretics

Question 31

Best diuretic for sodium spilling

Answer 31

Thiazide diuretic

Question 32

Clinical uses - Thiazide diuretics

Answer 32

``` HTN Edema Hypernatremia Diuresis Adjunct to loop diuretics ```

Question 33

Loop diuretic + thiazide, order of administration

Answer 33

Thiazide diuretic, wait 30-60min, loop diuretic

Question 34

Chlorothiazide - careful in which pts?

Answer 34

Renal injury - avoid in CrCl <30mL/min

Question 35

Chlorothiazide P/O/D?

Answer 35

O: 15min P: 30min D: 6-12h

Question 36

Good thiazide diuretic in renal injury patients

Answer 36

Metolazone - PO only

Question 37

Hydrochlorothiazide - caution

Answer 37

PO only, long DOA (6-12h)

Question 38

All diuretics will cause what?

Answer 38

Metabolic alkalosis | *except for carbonic anhydrase inhibitors

Question 39

Osmotic diuretics

Answer 39

Mannitol

Question 40

Osmotic diuretics clinical uses

Answer 40

increased ICP | Toxin excretion enhancement (rhabdo)

Question 41

Avoid what type of mannitol?

Answer 41

PO - poor bioavailability, avoid

Question 42

Mannitol Peak Effect

Answer 42

30-45min

Question 43

Important aspects of mannitol administration

Answer 43

- inspect vials for crystals (if + must heat) | - administer thru < 5 micron filter

Question 44

Adverse effects of mannitol

Answer 44

- Hypovolemia - Nephrotoxicity -- highly osmotic Rx (higher osmotic gap = higher risk of renal injury) - extravasation

Question 45

Caution using Mannitol in which patients

Answer 45

Patients without intact blood-brain barrier--> fluid may go into brain, increasing ICP/brain blood volume (OPPOSITE effect of goal)

Question 46

Potassium sparing diuretics are different from all other diuretics in that _____

Answer 46

may cause HYPERkalemia, not hypo

Question 47

AE amiloride

Answer 47

hyperkalemia | *along with all other K-sparing diuretic

Question 48

Potassium sparing diuretics Duration

Answer 48

days

Question 49

Advantage of Fenoldopam over Dopamine

Answer 49

Does not cause tachyarrythmia

Question 50

Persistent hypervolemic hyponatremia or euvolemic hyponatremia Tx

Answer 50

Free water excretion: | Vasopressin Receptor Antagonists (Conivaptan, Tolvaptan)

Question 51

Vasopressin receptor antagonists

Answer 51

Conivaptan (IV) | Tolvaptan (PO)

Question 52

MOA vasopressin receptor antagonists

Answer 52

block v1 (and v2) receptors --> vasodilation

Question 53

Patient population targeted by vasopressin receptor antagonists

Answer 53

Chronic liver/heart failure patients (increased ADH)

Question 54

Conivaptan blocks

Answer 54

V1 + V2 receptors

Question 55

Tolvaptan blocks

Answer 55

V2 receptors

Question 56

vasopressin antagonists AEs

Answer 56

hypovolemia hypotension muscle weakness liver dysfunction

Question 57

vasopressin antagonists - clinical implications in anesthesia

Answer 57

- Rx intxns (metabolized via CYP3A) | - Fast correction of serum sodium (permanent nerve injury --> osmotic demyelination syndrome)

Question 58

Avoid diuretic use in patients with

Answer 58

hypovolemia

Question 59

Drug intxns with diuretics

Answer 59

- concurrent nephrotoxins (NSAIDs, IV contrast, aminoglycosides, amphotericin, IV acyclovir) - digoxin (hypokalemia --> increased digoxin toxicity) - lithium (hyponatremia --> increased lithium toxicity) - corticosteroids (hypok) - aminoglycosides (ototoxicity) - ARB/ACE-I (hyperK)

Question 60

Should diuretics be held before surgery?

Answer 60

- hold the A.M. of procedure if used for management of HTN | - do NOT hold if used for management of severe liver/heart failure