Diuretics Flashcards
What are the three natriuretic peptides ?
a. Atrial natriuretic peptide (ANP)
b. Brain natriuretic peptide (BNP)
c. C-natriuretic peptide
What triggers the release of ANP and BNP?
Stretching of the Atria and ventricles d/t increased preload
How do ANP and BNP reduce blood volume and increase venous capacitance?
a. shifting fluid into the extra vascular compartment by increasing vascular permeability
b. act on kidney = more H20 and Na loss
c. dilation of arteries and veins
What are the four parts open Nephron?
a. glomerulus
b. proximal convoluted tubule (PCT)
c. loop of henle
d. distal convoluted tubule
What two components make up the distal nephron?
Final segment of the distal convoluted tubule and the collecting duct
What are the three basic renal processes?
a. Filtration
b. reabsorption
c. active secretion
Where does filtration take place in the kidneys?
The glomerulus
What part of the nephron is responsible for reabsorption of sodium and chloride?
a. Proximal convoluted tubule (approx. 65%)
b. Thick segment of the ascending limb of the loop of Henle (20%)
c. Early segment of the distal convoluted tubule (10%)
Aldosterone works on which part of the nephron?
The distal nephron
Aldosterone is what type of steroid?
Mineralocorticoid
Aldosterone causes what effect in the distal nephron?
Sodium retention in potassium excretion
How does aldosterone promote sodium potassium exchange in the distal nephron?
Stimulates the synthesis of more sodium potassium transport pumps
What are the three classes of diuretics?
a. Loop diuretics
b. thiazide diuretics
c. Osmotic diuretics
d. potassium sparing diuretics
Where does mannitol act within the nephron?
Proximal convoluted tubule
Where does lasix act within the nephron?
Thick segment -ascending limb of the loop of Henle
Where do thiazides act within the nephron?
Early distal convoluted tubule
Where does spironolactone act within the nephron?
Distal nephron
What is the mechanism of action for furosemide?
Blocking reabsorption of sodium and chloride in the thick segment of the ascending limb of the loop of Henle
Diuresis begins and lasts for how long after oral administration of furosemide?
a. 60 mins
Where is furosemide metabolised and how is it excreted?
a. Metabolized by the liver
b. excreted by the kidneys
What are the indications for Furosemide?
a. Pulmonary edema associated with CHF
b. Edema of hepatic, cardiac, or renal origin
c. uncontrolled hypertension
Why is furosemide effective in patients with severe renal impairment?
Camp remote diuresis even when Reno blood flow and GFR are low
What are adverse effects of Loop and thiazide diuretics?
a. hyponatremia
b. hypochloremia
c. hypokalemia
d. hypotension
e. ototoxicity
f. Hyperglycemia
g. Decreased HDL
h. increased LDL
Combining digoxin and furosemide can have what negative effect?
Ventricular dysrhythmias r/t digoxin toxicity
How does furosemide cause digoxin toxicity?
By reducing potassium levels
Ethacrynic acid is what class of drugs?
Loop diuretic
Torsemide is what class of drug?
loop diuretic
Bumetanide is what class of drug?
Loop diuretic
What is the mechanism of action for thiazide diuretics?
Blocks reabsorption of sodium and chloride any early segment of the distal convoluted tubule
Diuresis begins, peaks, and lasts for how long after oral admin of thiazide diuretic?
a. Begins: 2 hrs
b. Peaks: 4-6 hrs
c. Lasts: 12 hrs
What are the indications for hydro chlorothiazide?
a. Hypertension
b. Edema associated with mild to moderate heart failure
c. edema associated with hepatic or renal disease
What is spironolactone’s the mechanism of action?
aldosterone antagonist
What are the adverse effects of Spironolactone?
a. Hyperkalemia
b. Gynecomastia
c. menstrual irregularities
d. impotence
e. hirsutism
Triamterene is what class of drug?
a. Potassium sparing diuretic
Amiloride is what class of drug?
a. Potassium sparing diuretic
Diuresis begins and lasts for how long after oral admin of spironolactone?
a. Onset: 24-48 hrs
b. Lasts: 48-72 hrs
Diuresis begins and lasts for how long after oral admin of Triamterene?
a. Onset: 2-4 hrs
b. Lasts: 12-16 hrs
