Brainscape's Knowledge GenomeTM

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


See full index

Pharmacology > Exam 3 chapter 28 Diuretic drugs > Flashcards

Exam 3 chapter 28 Diuretic drugs Flashcards

1
Q

Diuretics are drugs that accelerate the rate of?

A

urine formation via a variety of mechanisms, resulting in the removal of sodium and water from the body.

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

The five main types of diuretics are

A

(1) carbonic anhydrase inhibitors (CAIs)
(2) loop diuretics
(3) osmotic diuretics
(4) potassium-sparing diuretics
(5) thiazide and thiazide-like diuretics.

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

most commonly used Diuretics

A

The loop, potassium-sparing, and thiazide diuretics are the most commonly used. Remember that the loop diuretics are more potent than the thiazides, combination diuretics, and potassium-sparing diuretics.

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

The Seventh Joint National Committee on the Detection, Evaluation, and Treatment of Hypertension reaffirmed the role of diuretics, especially the thiazides, as?

A

first-line drugs in the treatment of hypertension.

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

All diuretics work primarily in the?

A

kidney

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

The kidney filters out toxic waste products from the blood while simultaneously conserving essential substances. This delicate balance between elimination of toxins and retention of essential chemicals is maintained by the nephron. The nephron is the?

A

main structural unit of the kidney, and each kidney contains approximately 1 million nephrons.

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

The initial filtering of the blood takes place in the glomerulus, a cluster of capillaries surrounded by the glomerular capsule. The rate at which this filtering occurs is referred to as?

A

The glomerular filtration rate and it is used as a gauge of how well the kidneys are functioning as filters.

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

It is important to have a thorough knowledge of renal anatomy and physiology and how it relates to the action of the various diuretics; for example, if a loop diuretic is given, its site of action is the?

A

loop of Henle and it causes the excretion of sodium, potassium, and chloride into the urine.

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

The various diuretics are classified according to their?

A

sites of action within the nephron, their chemical structure, and their diuretic potency.

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

The most potent diuretics are the loop diuretics, followed by mannitol, metolazone (a thiazide-like diuretic), the thiazides, and the potassium-sparing diuretics. The potency of these diuretics is a function of?

A

where they work in the nephron to inhibit sodium and water resorption. The more sodium and water they inhibit from resorption, the greater the amount of diuresis and therefore the greater the potency.

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

Carbonic Anhydrase Inhibitors (CAIs) are chemical derivatives of sulfonamide antibiotics. They inhibit the activity of?

A

the enzyme carbonic anhydrase, which is found in the kidneys, eyes, and other parts of the body.
- work at the location of the carbonic anhydrase enzyme system along the nephron, primarily the proximal tubule

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

The carbonic anhydrase system in the kidney is located?

A

just distal to the glomerulus in the proximal tubules, where roughly two thirds of all sodium and water is resorbed into the blood.

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

For sodium and water to be resorbed back into the blood what must happen?

A

hydrogen must be exchanged for it.

  • without hydrogen, this cannot occur & the sodium and water will be eliminated w/urine
  • carbonic anhydrase makes hydrogen ions available for this exchange
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The CAIs reduce the formation of?

A

hydrogen and bicarbonate ions from carbon dioxide and water through the noncompetitive, reversible inhibition of carbonic anhydrase activity, resulting in a reduction in the availability of the ions, mainly hydrogen, for use by active transport system

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

An undesirable effect of CAIs is?

A

elevation of the blood glucose level and glycosuria in diabetic patients. This may be due in part to CAI enhanced potassium loss through the urine.

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

Therapeutic use of CAIs is in treatment of?

A

glaucoma, edema, and high-altitude sickness.

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

Undesirable effects of carbonic anhydrase inhibitors are?

A

metabolic abnormalities such as acidosis and hypokalemia, as well as drowsiness, anorexia, paresthesias, hematuria, urticaria, photosensitivity, and melena.

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

Because CAIs can cause hypokalemia, an increase in?

A

digoxin toxicity may occur when they are combined with digoxin. Use with corticosteroids may also cause hypokalemia.
-the effects of amphetamines, carbamazepine, cyclosporine, phenytoin, and quinidine may be increased when these drugs are taken concurrently w/CAIs

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

Loop diuretics (bumetanide, ethacrynic acid, furosemide, and torsemide) are very potent diuretics.

A

.

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

Loop diuretics have what effects?

These drugs act primarily along the?

A

Loop diuretics have renal, cardiovascular, and metabolic effects. These drugs act primarily along the thick ascending limb of the loop of Henle, blocking chloride and, secondarily, sodium resorption. They are also thought to activate renal prostaglandins, which results in dilatation of the blood vessels of the kidneys, the lungs, and the rest of the body.

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

Loop diuretics are used for?

A

edema associated with heart failure and hepatic or renal disease, hypertension, and to increase the renal excretion of calcium in patients with hypercalcemia. They may also be indicated for heart failure resulting from diastolic dysfunction.

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

Loop diuretics produce a potent diuresis and subsequent loss of fluid. The resulting decreased fluid volume leads to a?

A

decreased return of blood to the heart, or decreased filling pressures resulting in reduced blood pressure, pulmonary vascular resistance, systemic vascular resistance, central venous pressure, and left ventricular end-diastolic pressure.

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

Loop diuretics are particularly useful when?

A

rapid diuresis is needed because of their rapid onset of action. The diuretic effect lasts at least 2 hours.

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

Loop diuretics have a distinct advantage over thiazide diuretics in that?

A

their diuretic action continues even when creatinine
clearance decreases below 25 mL/min.
-this means that when kidney function diminishes, loop diuretics can still work

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

The major adverse effect of loop diuretics is?

A

electrolyte disturbances.

Prolonged administration of high dosages can also result in hearing loss stemming from ototoxicity.

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

Hypokalemia is of serious clinical importance. To prevent

hypokalemia, patients often receive?

A

potassium supplements along with furosemide.

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

main toxic effects of loop diuretics that require attention.

A

Electrolyte loss and dehydration, can result in circulatory failure, are main toxic effects of loop diuretics that require attention. Treatment involves electrolyte and fluid replacement.

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

Loop diuretics: Furosemide can produce?

A

erythema multiforme, exfoliative dermatitis, photosensitivity, and in rare cases, aplastic anemia.

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

Loop diuretics: Torsemide may rarely cause?

A

blood disorders, including thrombocytopenia, agranulocytosis, leukopenia, neutropenia, and Stevens-Johnson syndrome.

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

Interactions: Loop diuretics exhibit both?

A

neurotoxic and nephrotoxic properties, and they produce additive effects when given in combination with drugs that have similar toxicities.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Loop diuretics also affect certain laboratory results, which are?

A

increasing serum levels of uric acid, glucose, alanine aminotransferase, and aspartate aminotransferase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The osmotic diuretics include?

A

mannitol, urea, organic acids, and glucose. Mannitol, a nonabsorbable solute, is the most commonly used of these drugs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Mannitol works along the entire nephron, but primarily in the?

A

proximal tubule and descending limb of the loop of
Henle. Because it is nonabsorbable, it increases osmotic pressure in the glomerular filtrate, which in turn pulls fluid into the renal tubules from the surrounding tissues. This process also inhibits the tubular resorption of water and solutes, which produces a rapid diuresis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Mannitol is the osmotic diuretic of choice. Mannitol may induce?

A

vasodilation and in doing so increases both glomerular
filtration and renal plasma flow, making it an excellent
drug for preventing kidney damage during acute renal
failure. It is commonly used in the treatment of patients in
the early, oliguric phase of acute renal failure.

35
Q

Osmotic diuretic: Mannitol is also often used to?

A

reduce intracranial pressure and cerebral edema resulting from head trauma.
-In addition, mannitol treatment may be tried when elevated intraocular pressure is unresponsive to other drug therapies.

36
Q

Significant undesirable effects of mannitol include?

A

convulsions, thrombophlebitis, and pulmonary congestion. Other less significant effects are headaches, chest pains, tachycardia, blurred vision, chills, and fever.

37
Q

The currently available potassium-sparing diuretics are amiloride, spironolactone, and triamterene. These diuretics are also referred to as?

A

aldosterone-inhibiting diuretics because they block the aldosterone receptors. Spironolactone is a competitive antagonist of aldosterone, and for this reason it causes sodium and water to be excreted while
potassium is retained. It is the most commonly used of the
three drugs.

38
Q

Potassium-sparing diuretics work in the?

A

collecting ducts and distal convoluted tubules, where they interfere with sodium-potassium exchange. Spironolactone competitively
binds to aldosterone receptors and therefore blocks the
resorption of sodium and water that is induced by aldosterone
secretion.

39
Q

The potassium-sparing diuretics are relatively weak compared
with the thiazide and loop diuretics. When diuresis is
needed, they are generally used as?

A

adjuncts to thiazide treatment.
This combination is beneficial in two respects
1) drugs have synergistic diuretic effects
2) the two drugs counteract the adverse metabolic effects of one another.
-The thiazide diuretics cause potassium, magnesium,
and chloride to be lost in the urine, and the potassium sparing diuretics counteract this by elevating the potassium
and chloride levels.

40
Q

Potassium sparing diuretics: Spironolactone and triamterene are used to treat?

A

hyperaldosteronism and hypertension and to reverse the potassium loss caused by the potassium-wasting (e.g., loop, thiazide) diuretics.

41
Q

Potassium sparing diuretic: cardioprotective benefit of

spironolactone

A

Permanent ventricular myocardial wall damage, known as remodeling, may follow myocardial infarction. Various clinical trials have demonstrated a cardioprotective benefit of spironolactone in preventing this remodeling process due to aldosterone-inhibiting activity.

42
Q

Potassium sparing diuretic: Spironolactone can cause?

A

gynecomastia, amenorrhea, irregular menses, and postmenopausal bleeding.

43
Q

Potassium sparing diuretic: Triamterene may reduce?

A

folic acid levels and cause the formation of kidney stones and urinary casts. It may also precipitate megaloblastic anemia.

44
Q

Hyperkalemia may occur when potassium-sparing diuretics are used in combination with?

A

each other and/or with other potassium-sparing drugs such as angiotensin-converting enzyme (ACE) inhibitors.

45
Q

Thiazide diuretics are benzothiadiazines, chemical derivatives of sulfonamide antibiotics. The thiazide diuretics include?

A

chlorothiazide and hydrochlorothiazide. Hydrochlorothiazide is the most commonly prescribed and the least expensive of the thiazide diuretics.

46
Q

The thiazide-like diuretics are very similar to the thiazides
and include?

A

chlorthalidone, indapamide, and metolazone.

47
Q

The primary site of action of thiazides and thiazide-like

diuretics is the?

A

distal convoluted tubule, where they inhibit the resorption of sodium, potassium, and chloride, resulting in osmotic water loss.

48
Q

As renal function decreases, the efficacy of thiazides does what?

A

diminishes because delivery of the drug to the site of activity is impaired.

49
Q

The thiazide and thiazide-like diuretics are used in the treatment of?

A

edema of various origins, idiopathic hypercalciuria, and diabetes insipidus, in addition to hypertension. They are also used as adjunct drugs in the management of heart failure and hepatic cirrhosis.

50
Q

Major adverse effects of the thiazide and thiazide-like diuretics relate to?

A

electrolyte and metabolic disturbances—mainly reduced potassium levels and elevated levels of calcium, lipids, glucose, and uric acid. Other effects, such as gastrointestinal disturbances, skin rashes, photosensitivity, thrombocytopenia, pancreatitis, and cholecystitis, are less common.

51
Q

common adverse effects of metolazone therapy (thiazide diuretic)

A

Dizziness and vertigo are common adverse effects of metolazone therapy and are attributed to sudden shifts in the plasma volume brought about by the drug. Headache, impotence, and decreased libido are other important adverse effects of these drugs.

52
Q

CAIs can induce

A

Respiratory and metabolic acidosis
-both respiratory and metabolic acidosis can increase oxygenation during hypoxia by increasing ventilation, cerebral blood flow, and the dissociation of oxygen from oxyhemoglobin

53
Q

CAIs are used as adjunct drugs in the long term management of

A

Open-angle glaucoma that cannot be controlled by topical miotic drugs or epinephrine derivatives alone
-glaucomas are caused by obstruction of the outflow of aqueous humor. When CAIs are given, an increase in the outflow of aqueous humor results

54
Q

CAIs are also used in short term conjunction with miotics to?

A

Lower intraocular pressure in preparation for ocular surgery and as an adjunct in the Tx of secondary glaucoma

55
Q

Carbonic Anhydrase Inhibitor: Acetazolamide is also used to manage edema that is?

A

Secondary to heart failure that has become resistant to other diuretics

56
Q

As a class, CAIs are much less potent diuretics than loop diuretics and thiazides, and because of the metabolic acidosis they induce, their?

A

Effectiveness diminishes in 2-4 days

57
Q

Acetazolamide is also effective in both the prevention and Tx of the symptoms of?

A

High-altitude sickness. These symptoms include HA, nausea, SOB, dizziness, drowsiness, and fatigue

58
Q

Contraindications for carbonic anhydrase inhibitors (CAIs)

A
  • Known drug allergy
  • hyponatremia
  • hypokalemia
  • severe renal or hepatic dysfunction
  • adrenal gland insufficiency
  • cirrhosis
59
Q

Adverse effects of CAIs

A
  • metabolic abnormalities such as acidosis & hypokalemia
  • drowsiness
  • anorexia
  • paresthesias
  • hematuria
  • urticaria
  • photosensitivity
  • melena (blood in stool)
60
Q

CAI: Acetazolamide

A
  • contraindicated in pt’s who have shown hypersensitivity to it as well as in those with significant liver/kidney dysfunction, low serum potassium or sodium levels, acidosis, or adrenal gland failure
  • available in oral and parenteral forms
  • pregnancy C category
61
Q

Diuretics Nursing Process

A

1) Perform physical assessment/document findings, with emphasis on body systems affected by disease process or indication for diuretic & by potential drug-related adverse effects.
2) Assess baseline breath sounds, heart sounds, & neurologic status, check skin turgor, moisture levels of mucous membranes, & capillary refill.
3) Assess/document baseline fluid volume status & postural BPs before/during drug therapy due to diuretic-induced fluid volume loss.
4) Monitor excess and deficit fluid volume states include assessment of skin/mucous membranes, BP, pulse rate, I&O, & daily weights.
5) CAIs require close assessment of sodium/potassium levels. These drugs are not used in pt’s w/history of renal or liver dysfunction.
6) increased risk for digoxin toxicity w/diuretics that result in loss of potassium.
7) Loop diuretics more potent than thiazide diuretics, combination products, and potassium-sparing diuretics, so these drugs may pose more problems for elderly or those w/severe electrolyte loss and liver failure.
8) caution in administering loop diuretics w/other medications that are neurotoxic or ototoxic.
9) With potassium-sparing diuretics, hyperkalemia may be an adverse effect; therefore, assess pt’s serum levels of potassium. Potassium supplements, ACE inhibitors, and severe renal failure are contraindications.
10) Measure/record BP, pulse rate, I&O, & daily weights during diuretic therapy. Monitor for presence of dizziness, fainting, lightheadedness on standing or changing positions, weakness, fatigue, tremor, muscle cramping, changes in mental status, or cold clammy skin.
11) Diuretic therapy may precipitate cardiac irregularities or palpitations; therefore, continue to monitor heart rate and rhythm.
12) Fluid loss from action of diuretic may lead to adverse effect of constipation so preventative measures required, such as increased intake of fluids/fiber (unless contraindicated) and/or the use of natural bulk-forming products.
13) Monitor pt for occurrence of AE to diuretics, such as hypotension, electrolyte imbalances, metabolic acidosis, drowsiness (with CAIs), hypokalemia, tachycardia, and hyperkalemia (potassium-sparing diuretics).pressures.

62
Q

therapeutic effects of diuretics include?

A

resolution of or reduction in edema, fluid volume overload, heart failure, or hypertension, or a return to normal intraocular pressures.

63
Q

Diuretics: Why is serum electrolyte levels critical to assess for before and during therapy?

A

Because of the subsequent loss of electrolytes through the urine

  • specifically obtain/document serum potassium, sodium, chloride, magnesium, calcium, uric acid, and creatinine levels
  • arterial blood gas levels may also be ordered
64
Q

Loop diuretics: Cross-sensitivity has been documented in patients who are allergic to?

A

Sulfonamide antibiotics

  • loops may also cause severe skin reactions ( exfoliative dermatitis w/furosemide, Steven Johnson’s syndrome w/toreesmide)
  • thorough assessment of pt’s skin PRIOR to administration is important
  • potential drug-laboratory value interactions include increased serum uric acid and glucose levels
65
Q

The hemodynamic effects of loop diuretics are a?

A

Reduction in both preload and central venous pressures (filling pressures of ventricles). These actions make them useful in Tx of the edema associated w/heart failure, hepatic cirrhosis, & renal disease

66
Q

Because of their potent diuretic effect and the duration of action, loop diuretics are usually effective when given?

A

In a single daily dose.

  • This allows the renal tubule time to partially compensate for potassium depletion & other electrolyte derangements that often accompany around-the-clock diuretic therapy
  • despite this, the major AE of loop diuretics is electrolyte disturbances
  • prolonged administration of high dosages can rarely result in ototoxicity
67
Q

Loop diuretics produce potent diuresis and subsequent loss of fluid. The resulting decreased fluid volume leads to a decreased return of blood to the heart, or decreased filling pressures. This has the following cardiovascular effects:

A

1) Reduces BP
2) Reduces pulmonary vascular resistance
3) Reduces systemic vascular resistance
4) Reduces central venous pressure
5) Reduces left ventricular end-diastolic pressure

68
Q

The metabolic effects of loop diuretics are?

A

Secondary to the electrolyte losses resulting from the potent diuresis.

  • Major electrolyte losses include loss of sodium & potassium & to a lesser extent calcium
  • changes in the plasma levels of insulin, glucagon, and growth hormone have also been observed in association with loop diuretic therapy
69
Q

Contraindications for loop diuretics

A

-known drug allergy
-hepatic coma
-severe electrolyte loss
commonly given to pt’s in clinical practice

70
Q

Adverse effects of loop diuretic

A

-hypokalemia: to prevent pt’s receive potassium supplements along with furosemide

71
Q

Adverse effects of loop diuretic: Furosemide (Lasix)

A

Can produce erythemia multiforme, exfoliative dermatitis, photosensitivity, in rare cases aplastic anemia

72
Q

Loop diuretics: their combined use with thiazide (especially metolazone) results in?

A

The blockade of sodium & water resorption at multiple sites in the nephron, a property referred to as sequential nephron blockade, which increases their effects

73
Q

NSAIDs and loop diuretics

A

NSAIDs may diminish the reduction in vascular resistance induced by loop diuretics because these two drug classes have opposite effects on prostaglandin activity

74
Q

Loop diuretic: Furosemide (Lasix)

A
  • Used in management of pulmonary edema & edema associated w/heart failure, liver disease, nephrotic syndrome, & ascites. Also used in Tx of HTN, caused by heart failure
  • contraindicated in pt’s who have hypersensitivity to it or sulfanamides & in pt’s w/anuria, hypovolemia, or electrolyte depletion
  • oral form as solution, tabs, & injectable
  • pregnancy C category
75
Q

Nursing assessment: Because diuretics taken late in the afternoon or evening may lead to?

A

Nocturia (urination at night) and subsequent loss of sleep, these medications are usually scheduled

76
Q

Thiazide and thiazide-like diuretics are associated with adverse metabolic effects of ?

A

hyperglycemia; therefore, close monitoring of blood glucose levels are needed. Other metabolic disturbances include hyperlipidemia and hyperuricemia.

77
Q

Furosemide is a potent loop diuretic, and the most common adverse effect of loop diuretics is?

A

electrolyte imbalances. This results in major electrolyte losses of potassium and sodium and, to a lesser extent, calcium.

78
Q

Loop diuretic: Furosemide controlled infusion rate should not exceed at a rate of?

A

4 mg/min in patients with renal failure.

79
Q

To treat a patient diagnosed with primary hyperaldosteronism, the nurse would expect to administer which diuretic?

A

Spironolactone is the direct antagonist for aldosterone.

80
Q

To treat a patient with pulmonary edema, the nurse prepares to administer which diuretic to this patient?

A

Furosemide (Lasix)

Furosemide is a potent, rapid-acting diuretic that would be the drug of choice to treat pulmonary edema. The other medications are not potent enough to cause the diuresis necessary to treat this condition.

81
Q

Muscle weakness is a common symptom of?

A

hypokalemia.

82
Q 
A patient prescribed spironolactone (Aldactone) asks the nurse to assist with food choices that are low in potassium. The nurse would recommend which food choices? (Select all that apply.)
  Apples
  Bananas
  Pineapple
  Lean meat
  Winter squash
A

Apples
Pineapple
Lean meat

Spironolactone is a potassium-sparing diuretic that could potentially cause hyperkalemia. Bananas and winter (not summer) squash are high in potassium and should be avoided in patients taking spironolactone.

83
Q 
Potassium-sparing diuretics may cause which common adverse reactions? (Select all that apply.)
  Dizziness
  Headache
  Hyperkalemia
  Mental confusion
  Muscle weakness
A

Dizziness
Headache
Hyperkalemia

Hyperkalemia, dizziness, and headache are common adverse effects associated with potassium-sparing diuretics.

Pharmacology (28 decks)

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