Diuretics

Question 1

Thiazide/Thiazide-like

Answer 1

• Hydrochlorothiazide, chlorthalidone
• MOA: Blocks Na+/Cl- transporter in distal tubule - prevents Na+ absorption
• Decreases CO by decreasing BV due to Na+/H2O excretion
• FIRST LINE for uncomplicated HTN
• Can also use for mild edema with heart failure and with loop diuretic with edema from heart failure

Question 2

Thiazide SE

Answer 2

• ALL cause hypokalemia
• Hyponatremia
• Hyperglycemia
• Hyperuricemia

Question 3

How Thiazide diuretics cause hypokalemia…

Answer 3

• From increase in delivery of Na+ to collection duct

- Some Na+ exchanged for K+ causing its excretion and therefore wasting

Question 4

Thiazide Symptoms

Answer 4

• Muscle cramps, weakness, fatigue
• Severe dizziness
• Polyuria
• Polydipsia
• Exacerbate gout

Question 5

Potassium Sparing Diuretic Types

Answer 5

• Sodium Channel Inhibitors

- Mineralocorticosteroid (MR) antagonists

Question 6

Sodium Channel Inhibitors

Answer 6

• Triamterene
• Prevent K+ wasting
• MOA: block Na+ channel in collecting duct - prevents Na+ reabsorption and excretion of K+
• Can also be used for Hypokalemia
• SE: Hyperkalemia

Question 7

Hypo/Hyperkalemia Symptoms

Answer 7

• Weakness
• Fatigue
• Muscle cramps

Same for each

Question 8

Mineralocorticosteroid (MR) Antagonists

Answer 8

• Spironolactone (Aldactone)
• Prevent K+ wasting and treat HTN
• MOA: complete with aldosterone in collecting duct - decreases Na+ absorption and increases K+ retention
• Decreases CO by decreasing BV by causing NA+/H2O excretion
• FIRST LINE for resistant HTN (used fourth)

Question 9

Resistant HTN

Answer 9

Not controlled by combination of 3 drugs from different classes at maximal doses, including a diuretic.

Question 10

MR Antagonist SE

Answer 10

-Hyperkalemia

Spironolactone ONLY

• Menstrual irregularities
• Breast Pain
• Gynecomastia

Question 11

K+ Sparing Other Uses

Answer 11

• Heart failure
• Primary hyperaldosteronism
• Liver cirrhosis

Question 12

Loop Diuretic

Answer 12

• Furosemide (Lasix)
• Blocks Na+/K+/Cl- reabsorption in thick, ascending loop of Henle
• Causes profound increase of natriuresis and diuresis
• LAST RESORT for resistant hypertension