Module 14: Drugs Acting on the Renal System (Part I)

Renal cortex

It refers to the outer, lighter region of the kidneys.

Liver

What organ is accommodated at the site of the kidneys, making the right kidney lower than the left?

Renal medulla

It refers to the darker region of the kidney deep into the renal cortex.

Renal pyramids

These refer to triangular regions within the renal medulla.

Renal hilum

It refers to the structure through which blood vessels, nerves, and the ureter pass.

Renal calyces

These refer to cuplike extensions in the renal pelvis that drain filtrate from the renal pyramids into the ureter.

Nephron

What is the functional unit of the kidney?

Protein, albumin, amino acids, glucose, and sugar

What solutes cannot pass through the glomerular membrane and therefore stay in the glomerulus?

99%

How many percent of water is reabsorbed in total?

30 cc/hr

What is the normal urine output in cc per hour?

Glomerular filtration

This involves the process of water, along with smaller solutes such as sugar and ions, moving out of the capillary walls and into the renal tubule.

Tubular reabsorption

This involves the process of water, along with glucose, amino acids, and certain ions, being reabsorbed from the filtrate back into the capillary blood.

Tubular secretion

This involves the process of hydrogen, potassium, creatinine, and drugs entering the urine.

Diuretics

These medications induce urination through the inhibition of sodium and water reabsorption.

50-55%

What percentage of sodium is being reabsorbed in the proximal tubules?

30-45%

What percentage of sodium is being reabsorbed in the loop of Henle?

5-10%

What percentage of sodium is being reabsorbed in the distal tubule?

<3%

What percentage of sodium is being reabsorbed in the collecting tubule?

Glomeruli

Drugs that act on the tubules closest to the __ have the greatest effect on natriuresis in the urine.

Decrease sodium reabsorption

What must be done to increase urine production?

Thiazides

These are weak diuretics that promote Na, K, Cl, Mg, HCO3, and water excretion, but promote calcium and uric acid reabsorption. These drugs are indicated for essential hypertension (first choice) and edema in patients with mild to moderate heart failure.

Distal convoluted tubule

Thiazides act on which part of the nephron?

Hypercalcemia

What is one side effect of taking thiazides?

False

True or False: Thiazides are not given for immediate diuresis, as they take approximately 12 hours to take effect after administration.

4-6

How many hours does it take for thiazides to reach their peak effect?

Loop Diuretics (Potassium-Wasting Diuretics)

Also known as high-ceiling diuretics, these drugs are potent water, sodium, calcium, potassium, and magnesium wasting and have the greatest diuretic effect.

Ascending loop of henle

Loop diuretics act on which part of the nephron?

60 minutes, 8 hours

When is the peak effect and duration of action for PO loop diuretics? (Two answers.)

Osmotic diuretics

These drugs increase the concentration and sodium reabsorption, increasing urine production indicated primarily for patients with cerebral edema and increased IOP.

Proximal convoluted tubule and descending loop of Henle

Osmotic diuretics act on which part of the nephron?

Mannitol

What is the most commonly prescribed osmotic diuretic that has a high tendency to crystallize on stock?