chapter 29 - week 2

Question 1

what are diuretic drugs

Answer 1

• Drugs that accelerate the rate of urine formation
• Result in the removal of sodium and water
• Mainstay of therapy for the treatment of hypertension and heart failure and for prevention of kidney damage during acute kidney injury

Question 2

sodium in relation to the nephron

Answer 2

In the nephron, where sodium goes, water follows.
60 to 70% of sodium and water is returned to the bloodstream by the proximal convoluted tubule.
20 to 25% of all sodium is reabsorbed 
into the bloodstream in the ascending loop of Henle.
5 to 10% is reabsorbed in the distal convoluted tubule.
Collecting duct is the final common pathway for the filtrate that started in the glomerulus.
If water is not absorbed, it is excreted as urine.

Question 3

types of diuertic drugs

Answer 3

• Carbonic anhydrase inhibitors
• Loop diuretics
• Osmotic diuretics
• Potassium-sparing diuretics
• Thiazide and thiazide-like diuretics

Question 4

loop diuretics names

Answer 4

bumetanide
ethacrynic acid (rarely used clinically)
furosemide (Lasix®)

Question 5

loop diuretics mechanism of action

Answer 5

• Possess kidney, cardiovascular, and metabolic effects
• Act directly on the ascending limb of the 
loop of Henle to block chloride and sodium resorption
• Increase kidney prostaglandins, resulting in the dilation of blood vessels and reduced kidney, pulmonary, and systemic vascular resistance
• Useful in treatment of edema

Question 6

Loop diuretics:drug effect

Answer 6

• Rapid onset; last at least 2 hours
• Potent diuresis and subsequent loss of fluid
• Decreased fluid volume causes a reduction in:
  * Blood pressure
  * Pulmonary vascular resistance
  * Systemic vascular resistance
  * Central venous pressure
  * Left ventricular end-diastolic pressure
• Potassium and sodium depletion
• Small calcium loss

Question 7

loop diuretics indictations

Answer 7

• Edema associated with heart failure and liver or kidney disease
• Hypertension (to control)
• Kidney excretion of calcium in patients with hypercalcemia (to increase excretion)
• Heart failure resulting from diastolic dysfunction

Question 8

loop diuretics adverse effects

Answer 8

• Central nervous system: Dizziness, headache, tinnitus, blurred vision
• Gastrointestinal: Nausea, vomiting, diarrhea
• Hematological: Agranulocytosis, neutropenia, thrombocytopenia
• Metabolic: Hypokalemia, hyperglycemia, hyperuricemia

Question 9

loop diuretics interactions

Answer 9

• Neurotoxic(alters the normal activity of the nervous system)
• Nephrotoxic (Poisonous or damaging to the kidney)
• Increase serum levels of uric acid, glucose, alanine aminotransferase, and aspartate aminotransferase.
• thiazide (metolazone): sequential nephron blockade
• Nonsteroidal anti-inflammatory drugs (NSAIDs) may decrease the reduction of vascular resistance.

Question 10

flurosemide

Answer 10

• Most commonly used loop diuretic
• Uses: pulmonary edema and the edema associated with heart failure, liver disease, nephrotic syndrome, ascites, hypertension

Question 11

osmotic diuretics names

Answer 11

• mannitol (Osmitrol®)
• Most used osmotic diuretic
• Urea
• Organic acids
• Glucose

Question 12

osmotic diuretics mechanism of action

Answer 12

• Works along entire nephron but mostly in the proximal tubule and descending loop of Henle
• Nonabsorbable, producing an osmotic effect
• Pull water into the renal tubules from the surrounding tissues
• Inhibit tubular resorption of water and solutes, thus producing rapid diuresis

Question 13

osmotic diuretic durg effects

Answer 13

• Increase glomerular filtration rate and renal plasma flow; help to prevent kidney damage during acute kidney injury
• Reduce intracranial pressure or cerebral edema associated with head trauma
• Reduce excessive intraocular pressure (fludi pressure of the eye)

Question 14

osmotic diureteics indications

Answer 14

• Treatment of patients in the early, oliguric phase of acute kidney injury
• To promote excretion of toxic substances
• To reduce intracranial pressure
• Treatment of cerebral edema
• Used as a genitourinary irrigant in the preparation of patients for transurethral surgical procedures

Question 15

osmotic diureteic adverse effects

Answer 15

• Convulsions
• Thrombophlebitis
• Pulmonary congestion
• Other: headaches, chest pains, tachycardia, blurred vision, chills, and fever

Question 16

mannitol (osmitrol)

Answer 16

Intravenous (IV) infusion only
May crystallize when exposed to low temperatures. Therefore, vials are often stored in a warmer.
Use of a filter is required.

Question 17

potassim sparing diuretic names

Answer 17

• Also known as aldosterone-inhibiting diuretics
• amiloride (Midamor®)
• spironolactone (Aldactone®)
• triamterene
• triamterene in combination with hydrochlorothiazide

Question 18

potassium-sparing diuretic mechanism of action

Answer 18

• Work in collecting ducts and distal convoluted tubules
• Interfere with sodium–potassium exchange
• Competitively bind to aldosterone receptors
• Block resorption of sodium and water usually induced by aldosterone secretion

Question 19

potassium sparing siuretic drug effects

Answer 19

• Relatively weak compared with the thiazide and loop diuretics
• Competitively block aldosterone receptors and inhibit their action
• Promote the excretion of sodium and water

Question 20

potassoim sparing indications

Answer 20

spironolactone and triamterene
* Hyperaldosteronism
* Hypertension
* Reversing potassium loss caused by potassium-wasting diuretics
* Certain cases of heart failure: prevention of remodelling

amiloride
* Similar to spironolactone and triamterene but less effective in the long term

*

Question 21

potassoim sparing adverse effects

Answer 21

• Central nervous system: Dizziness, headache
• Gastrointestinal: Cramps, nausea, vomiting, diarrhea
• Other: Urinary frequency,
weakness, hyperkalemia

spironolactone (Aldactone®)
* Gynecomastia
* Amenorrhea
* Irregular menses
* Postmenopausal bleeding

Question 22

potassoim sparing interactions

Answer 22

• Lithium
• Angiotensin-converting enzyme inhibitors
• Potassium supplements
• NSAIDs

Question 23

thiazide and thaizide-like diuretics names

Answer 23

Thiazide diuretics
* hydrochlorothiazide (Urozide®)

Thiazide-like diuretics
* metolazone (Zaroxolyn®)
* chlorthalidone
* indapamide

Question 24

thiazide and thaizide like consdierations

Answer 24

Thiazides should not be used if creatinine clearance is less than 30 to 50 mL/min (normal is 125 mL/min).
Metolazone remains effective to a creatinine clearance of 10 mL/min.

Question 25

thiazide and thiazide-like mechanism of action

Answer 25

* Inhibit tubular resorption of sodium, chloride, and potassium ions * Action primarily in the distal convoluted tubule * Result in osmotic water loss * Dilate the arterioles by direct relaxation * Decrease preload and afterload

Question 26

thiazide and thiazide like indication

Answer 26

* Hypertension (one of the most prescribed group of drugs for this) * Edematous states * Idiopathic hypercalciuria * Diabetes insipidus * Heart failure caused by diastolic dysfunction

Question 27

thiazide and thiazide likeadverse effects

Answer 27

* Central nervous: Dizziness, headache, blurred vision * Gastrointestinal: Anorexia, nausea, vomiting, diarrhea * Genitourinary: Erectile dysfunction * Hematological: Jaundice, leukopenia, agranulocytosis * Integumentary: Urticaria, photosensitivity * Metabolic: Hypokalemia, glycosuria, hyperglycemia, hyperuricemia, hypochloremic alkalosis

Question 28

nursing implications - before diuretics

Answer 28

* Perform a thorough patient history and physical examination. * Assess baseline fluid volume status, intake and output, serum electrolyte values, weight, and vital signs (especially postural blood pressure). * Assess for disorders that may contraindicate or necessitate cautious use of these drugs. * Instruct patients to take the medication in the morning if possible to avoid interference with sleep patterns. * Monitor serum potassium levels during therapy. * Teach patients to maintain proper nutritional and fluid volume status. * Teach patients to eat more potassium-rich foods when taking any diuretics but the potassium-sparing drugs. * Foods high in potassium include bananas, oranges, dates, apricots, raisins, broccoli, green beans, potatoes, tomatoes, meats, fish, wheat bread, and legumes. * Instruct patients to notify their primary care provider immediately if they experience rapid heart rates or syncope (reflects hypotension or fluid loss). * Teach patients to change positions slowly and to rise slowly after sitting or lying, to prevent dizziness and fainting related to orthostatic hypotension. * Encourage patients to keep a log of their 
daily weight. * Remind patients to return for follow-up visits and laboratory work.

Question 29

nurising implications montioring diuretics

Answer 29

* Patients taking diuretics along with digoxin should be taught to watch for 
digoxin toxicity. * Patients with diabetes mellitus who are taking thiazide or loop diuretics should be told to monitor blood glucose and watch for elevated levels. * Patients who have been ill with nausea, vomiting, or diarrhea should notify their primary care provider because fluid and electrolyte imbalances can result. * Signs and symptoms of hypokalemia include anorexia, nausea, lethargy, muscle weakness, mental confusion, and hypotension * Excessive consumption of licorice can lead to additive hypokalemia in patients taking thiazides. * Monitor for adverse effects: * Metabolic alkalosis, drowsiness, lethargy, hypokalemia, tachycardia, hypotension, leg cramps, restlessness, decreased mental alertness * Monitor for hyperkalemia with potassium-sparing diuretics. * Monitor for therapeutic effects: Reduction of edema Reduction of fluid volume overload Improvement in manifestations of heart failure Reduction of hypertension Return to normal intraocular pressures