Ch 41: Diuretics

Question 1

2 major applications of diuretics

Answer 1

1. Treatment of hypertension
2. Mobilization of edematous fluid associated with heart failure, cirrhosis, or kidney disease

Question 2

Why can diuretics be used to prevent renal failure?

Answer 2

Belong of their ability to maintain urine flow

Question 3

3 basic functions of kidney

Answer 3

1. Cleansing of extracellular fluid & maintenance of ECF volume and composition
2. Maintenance of acid-base balance
3. Exertion of metabolic wastes and foreign substances

Question 4

3 basic processes of kidneys

Answer 4

1. Filtration
2. Reabsorption
3. Active secretion

Question 5

How do diuretics work?

Answer 5

Blockade of sodium & chloride reabsorption
→ prevents passive reabgorption of water
→ promotes excretion of water & solutes

Question 6

The increase in urine flow is directly related to…

Answer 6

The amount of sodium and chloride reabsorption that it blocks

Question 7

How much will a diuretic increase daily urine output at a filtrate production of 180L a day

Answer 7

1.8 L for each 1% of solute reabsorption that is blocked

Question 8

Adverse effects on ECF

Answer 8

Hypovolemia (from excessive fluid loss)
Acid-base imbalance
Altered electrolyte levels

Question 9

How to minimize adverse effects of diuretics?

Answer 9

Use short-acting diuretics
Time drug administration zo kidney can operate drug-free between diuresis

Question 10

4 major categories of diuretic drugs (and 5th)

Answer 10

1. Loop diuretics
2. Thiazide diuretics
3. Osmotic diuretics
4. Potassium-sparing diuretics

S. Carbonic anhydrase inhibitors

Question 11

Loop diuretics

Answer 11

Most effective
Produce most loss of fluid & electrolytes
Site of action: loop of hence

Question 12

Furosemide [lasix] Mechanism of action

Answer 12

Acts in thick segment of ascending loop of henle
Blocks reabsorption of sodium & chloride
Prevents passive reabsorption of water

Question 13

Furosemide [lasix] pharmacokinetics

Answer 13

Orally, IV, & IM
Orally: diuvesis begins in 60 minutes, lasts 8 hours (not for rapid onset)
IV: effects in 5 minutes, lasts 2 hours, for critical situations

Undergoes hepatic metabolism followed by renal excretion

Question 14

Furosemide [lasix] therapeutic uses

Answer 14

Used for situations needing a rapid mobilization of fluid

1. Pulmonary edema associated with congestive heart failure
   2- edema of hepatic, cardiac, or renal origin that was been unresponsive to other diuretics
2. Hypertension that can’t be controlled by other diuretics