Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > Diuretics > Flashcards

Diuretics Flashcards

1
Q

Functions of the Kidneys (5 main functions)

A
  1. Regulation of water and inorganic-ion balance
  2. Removal of metabolic waste products from the blood (urea, uric acid and creatinine)
  3. Removal of foreign chemical from the blood and their excretion in the urine
  4. Gluconeogenesis (during prolonged fasting)
  5. Secretion of hormone/circulating factors
    a. EPO
    b. Renin
    c. 1,25-Dihydroxyvitamin D3
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Macula densa senses what?

A

specialized cells sense Na+ load

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

JG cells are located? Secrete? (under what portion of the PNS?)

A 
Afferent arteriole;
Secrete Renin (modulated by sympathetic nervous system)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Reabsorption is accomplished through what two methods?

A

Diffusion and Mediated transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Diuretics act predominantly on _____?

A

Reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Diuretics produce a _____ in volume of urine?

A

Increase in volume of urine;
Also can change composition of urine;
Predominant effect of diuretics: Na+ and H2O reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Glomerular process?

A

Formation of an ultrafiltrate of plasma (free of cells and protein)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Primary role of the Proximal Tubule?
Major site: _____ Na+ transport
Major site for solute secretion - EXCEPT for _______

A

Reabsorption of water and solutes;
ACTIVE Na+ transport;
Except for K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

__% of filtered Na+ load reabsorbed

A

~65%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

H+ secretion/ exchanged for Na+;

helps in reabsorption of bicarbonate

A

Carbonic anhydrase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Loop of Henle:

creates hyp__osmotic interstitial fluid though the _______ multiplier system

A

Hyperosmotic;

Countercurrent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Descending thin limb:

highly permeable to ___? No ____ reabsorption

A

highly permeable to H2O; No Na+ reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ascending thin limb is impermeable to?

A

Water; Na+ diffuses out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Thick ascending limb:

Active ___ transport

A

Na+; through Na+K+/2Cl- symport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

LAte distal tubule and cortical collecting duct:

active Na+ _____ in exchange for ____?

A

reabsorption; K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Aldosterone promotes ______ in Late distal tubule and cortical collecting duct?

A

Na+/K+ exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In collecting duct, luminal membrane has ___ channel? Unique to this part of renal tubule

A

K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Aldosterone induces synthesis of _____ channels in luminal membrane of late distal tubule and cortical collecting duct?

A

Na+ and K+ channels;

Promotes Na reabsorption and K secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Na+/Cl- symport is _____ sensitive

A

thiazide;

this occurs proximal to site for aldosterone action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

RAAS: JG apparatus
Macula densa senses _____ Na+ load => _____ cells secrete renin => increased renin => increased ____ => increased aldo => decreased na excretion

A

decreased Na load;
JG cells secrete renin;
increased AngII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Aldo also controlled by __

A

K+;

increased K in ECF of adrenal cortex => increased aldo secretion => increased K excretion by kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Medullary collecting duct is major site for ____ control of Na and water reabsorption

A

hormonal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

_____ required for H2O reabsorption

A

ADH/vasopressin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Characteristics of Osmotic Diuretics?

A

Freely filtered; Limited reabsorption; pharmacologically inert; resistant to metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Site/MOA of Osmotic diuretics

A

Proximal tubule and loop of Henle - osmotic effect, hold water in tubular lumen;
Reduced Na reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Effects of Osmotic diuretics

A

initial expansion of intravascular fluid volume, inreased renal blood flow;
Increased excretion of urinary electrolytes - isosmotic water loss;
Maintain diuretic effect during hypovolemia or shock - trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

name 4 osmotic diuretics

A

Mannitol (preferred)
Glycerol
NaCl
Ammonium chloride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Mannitol-

Must be given ____

A

perenterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Mannitol Indications

A

Cerebral edema, glaucoma, prophylaxis of acute renal failure (questionable value if given after renal damage), promote excretion of certain toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Mannitol contraindications

A

Congestive heart failure (esp with pulmonary edema);

Anuric renal failure that does not respond to a test dose

31
Q

Mannitol- Large or small anmal

A

Both; no withdrawal time for food animals

32
Q

Glycerol- can be given ____; metabolized and may cause ______

A

Orally;

Hyperglycemia

33
Q

Glycerol Indication

A

Treatment of glaucoma - reduces ocular pressure, sometimes used in small animals, but mannitol is preferred osmotic agent

34
Q

Glycerol Contraindications

A

Diabetes mellitus

35
Q

NaCl - Increases ____ consumption

A

water

36
Q

NaCl - added to ____

A

feed (sheep,calves)

37
Q

NaCl- Increases ______ volume; in order to dilute ______

A

Increases urine volume; used for diluting stone forming substances - Ca2+, Mg2+

38
Q

Ammonium chloride- given ____ - has ___ diuretic action

A

orally; transient

39
Q

Main use of ammonium chloride

A

urinary acidifier; used to manage cystic calculi or chronic urinary tract infections

40
Q

Ammonium Chloride Contraindications

A

Patients with systemic acidemia (can cause subclinical metabolic acidosis); use caution in patients with renal disease

41
Q

Ammonium chloride

Large or small animals?

A

both; no withdrawal time in food animals

42
Q

Carbonic Anhydrase Inhibitors: Site/MOA

A

Primary proximal tubule - Decreased H+ secretion, Na+ and HCO3- reabsorption;
Minor effects at collecting duct

43
Q

Carbonic Anhydrase Inhibitors: Effect

A

Increased excretion of HCO3, Na, K and water(transient);
Metabolic acidosis and decreased excretion of ammonia
Decreased production of aqueous humor

44
Q

Name 3 Carbonic Anhydrase Inhibitors

A

Methazolamide
Acetazolamide
Dichlorphenamide

45
Q

Carbonic Anhydrase Indications:

A

Major use: Glaucoma
(Methazolamide used more often; other regimens preferred for glaucoma)
Can be used to produce alkaline urine (transient)
Also been used for udder edema in cattle (extralabel)

46
Q

Carbonic Anhydrase Contraindications

A

Allergy to sulfonamides
History of renal or urinary calculi that form in alkaline urine
Presence of Na or K depletion
Presence of metabolic or respiratory acidosis

47
Q

Loop diuretics AKA

A

High Ceiling diuretics

48
Q

Loop diuretics Site/MOA

A

Thick ascending limp of loop of henle;
inhibit Na/K/2Cl symport;
inhibit paracellular diffusion of Na, K, Mg, Ca;
Minor- some inhibition of Na and CL reabsorption in proximal and distal tubules

49
Q

Loop diuretics characteristics

A

Most Common diuretic in VetMed
Highly protein bound in plasma, but actively secreted into proximal tubule
Profound diuresis - most effective for edematous conditions “high ceiling diuretics”

50
Q

Loop diuretics Effects

A

1 Profound increase in Na excretion, also cl, h2o, k, h, ca, mg (most profound Na and Ca)
2 Mild systemic venodilator (acutely increase renal blood flow
3 Bronchodilator in humans horses and guinea pigs
4 Increased renin secretion (due to decreases plasma Na)
5 Metabolic alkalosis

51
Q

Name 3 loop diuretics

A

Furosemide (preferred)
Bumetanide (25-50x more potent)
Torsemide (more potent and ~2x longer duration)

52
Q

Furosemide PK:

Onset of action, peak effect, duration

A

Onset of action: IV-5 min, Oral-1hr
Peak effect: IV-30min, Oral- 1-2hrs
Duration: IV- 2-3hrs, Oral- 4-6hrs

53
Q

Loop Diuretics Indications:

A
  1. Congestive heart failure (ascites, pleural effusion, pulmonary edema) ie noninflammatory edema
  2. Hypercalcemia
  3. prophylaxis for epistaxis (exercise induced pulmonary hemorrhage in the equine
  4. Udder edema (food animal withdrawal time = 48hrs)
  5. Cerebral edema (if havent had significant blood loss)
  6. Only diuretic with significant effect in patients with impaired renal function
54
Q

Loop Diuretics: Contraindications/Cautions

A
  1. Anuria/progressive renal disease
  2. Hypokalemia
  3. Allergy to sulfonamides
  4. Possible ototoxicity with rapid IV administration (rare)
  5. Ca wasting cows may precipitate milk fever
  6. Beware of profound dehydration (esp if stops drinking)
  7. NSAIDs attenuate natriuretic effects of furosemide
55
Q

Thiazide Diuretics AKA

A

Rescue Diuretics

56
Q

Thiazide Site/MOA

A

Early distal tubule (before site for Na/K exchange)
Inhibit Na/Cl symport
Also minor inhibition carbonic anhydrase n proximal tubule

57
Q

Thiazide Characteristics

A
  1. Secreted into proximal tubule

2. Decreased Na reabsorption and increased K secretion (increased Na load in tubular fluid, promotes Na/K exchange)

58
Q

Thiazide Effects

A
  1. Moderate Diuresis - rarely used as a first choice diuretic
  2. increased excretion of Na, Cl, and K
  3. Decreased excretion of Ca
59
Q

Name two Thiazide diuretics

A

Hydrochlorothiazide (preferred)

Chlorothiazide

60
Q

Thiazide diuretics

PK

A

Onset of Action (oral): 2 hrs for hydrochlorothiazide, 1 hr for chlorothiazide
Peak effect at 4 hrs
Duration ~12 hours

61
Q

Thiazide Indications

A
  1. Not first choice for monotherapy
  2. Refractory feart failure (resistant to furosemide) - a. Rescue with thiazide - canine (diuretic effect on own + restores diuresis to furosemide)
  3. Ascites due to liver disease
  4. Diabetes insipidus (paradoxically decreases urine flow)
  5. Udder edema (extralabel)
62
Q

Thiazide Contraindications

A

1 Hypokalemia
2 Diabetes Mellitus
3 Use with caution in congestive heart failure
4 If using as “rescue” decrease dose of furosemide by 50%

63
Q

K sparing agents Site/MOA

A

Site: late distal tubule and collecting duct
MOA: Atagonize Aldo (spironolactone) - blocks active Na/L exchange
OR
Block sodium channels (triamterine) in tubular cells of the late distal tubule and collecting duct

64
Q

K Sparing Agents

Characteristics

A

Actively secreted by the renal tubules

65
Q

K Sparing Agents

Effects

A

1 Increased excretion of NaCl

2 Decreases excretion of K, H, Ca, Mg

66
Q

K Sparing Agents

PK: spironolactone

A
  1. protein bound, but actively secreted by renal tubules

2. gradual onset and offst of action - peak effect 2-3 days after therapy is started

67
Q

K sparing agents

Indications: spironolactone

A
  1. Used in small animals - mainly dogs and cats
  2. Refractory heart failure
    a. used mainly in combination with other diuretic agents (primarily furosemide-small additional diuretic effect and decreases K excretion)
    b. spironolactone + ACE inhibitor: be aware of risk of hyperkalemia, unless furosemide is also given
  3. Ascites caused by right heart failure, hepatic disease, or nephrotic syndrome
68
Q

K sparing agents

Contraindications: spironolactone

A
  1. Hyperkalemia
  2. Use caution administering with other drugs that increase blood K such as ACE inhibitors or NSAIDS
  3. Not advisable to combine with ACE inhibitor unless also giving furosemide
  4. Induces hepatic microsomal enzymes (watch for drug interactions)
69
Q

K Sparing Agents

PK: triamterene

A

Action begins within 2 hrs, peaks at 6-8hrs and lasts 12-16 hrs
Used infrequently in VetMed

70
Q

Xanthines (mild diuretic effects)

Name two

A

Caffeine (toxicosis)

Theobromine (chocolate toxicitiy)

71
Q

Xanthines Characteristics/effects

A
  1. not used as diuretics but have mild diuretic effect
  2. positive inotropic and chronotropic effects on the heart
  3. CV effects increase renal blood flow, glomerular filtration rate, and medullary blood flow
  4. Inhibit tubular NaCl reabsorption
  5. Major use = relax airway smooth muscle
  6. Can overstimulate the CNS
72
Q

Xanthines: SIte of Action

A

We dont really know?

73
Q

Compounds: Xanthines

A

Theophylline, aminophylline - drugs used to treat pulmonary hypertension, feline and equine asthma, canine chronic bronchitis (may have mild diuretic effect)

Pharmacology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions