Diuretics Flashcards
What is the primary function of diuretics?
Increase urine flow and Na(^+) and Cl(^-) excretion.
What is the term for the excretion of Na(^+) in urine?
Natriuresis.
What does diuresis refer to?
Increased urine flow rate.
What are the two types of diuresis recognized in clinical medicine?
- Solute diuresis * Water diuresis
What is solute diuresis caused by?
A decrease in renal tubular reabsorption of solute.
What can promote water diuresis without solute diuresis?
Drugs that impair the action of antidiuretic hormone (ADH).
What are vaptans classified as?
Aquaretics.
How are diuretics classified?
According to their chemical structure and site of action.
List the five groups of diuretics.
- Osmotic diuretics * Carbonic anhydrase inhibitors * Loop diuretics * Distal tubule diuretics * K(^+)-sparing diuretics
What is the prototype drug for osmotic diuretics?
Mannitol.
Where do loop diuretics mainly act?
Thick ascending Henle’s loop.
What is the mechanism of action for loop diuretics?
Inhibit Na/K/2Cl cotransporter.
What is the natriuretic potency of loop diuretics?
20–25%.
What are the physiologic effects of diuretics on renal blood flow?
Changes in RBF vary by diuretic type.
What effect do osmotic diuretics have on urine volume?
↑↑ urine volume.
What is one clinical use of diuretics?
Treatment of generalized edema states.
Which diuretic is commonly used for congestive heart failure?
Furosemide.
What complication is most commonly associated with thiazide diuretics?
Hyponatremia.
What phenomenon occurs when a diuretic loses effectiveness after several days?
Diuretic breaking phenomenon.
What causes the diuretic breaking phenomenon?
Increased Na(^+) and water reabsorption in the proximal tubule.
What is the urinary Na(^+)-to-K(^+) ratio indicative of?
Plasma aldosterone activity.
What is Finerenone classified as?
A third-generation mineralocorticoid antagonist.
What is the main effect of Sodium Glucose Cotransporter-2 (SGLT2) inhibitors?
Improve serum glucose levels in type 2 diabetes.
Fill in the blank: The mechanism of action for carbonic anhydrase inhibitors is to inhibit _______.
carbonic anhydrase.
True or False: K(^+)-sparing diuretics can cause hyperkalemia.
True.
What is the effect of thiazide diuretics on Ca(^{2+}) excretion?
↓ Ca(^{2+}) excretion.
What class of drugs includes canagliflozin, empagliflozin, luseogliflozin, and tofogliflozin?
SGLT2 inhibitors
SGLT2 inhibitors are used for the treatment of type 2 diabetes.
Which SGLT2 inhibitors have been approved in Japan for the treatment of type 1 diabetes?
Ipragliflozin and dapagliflozin
These drugs are noted for their specific approval in Japan.
What is the mechanism of action for SGLT2 inhibitors?
Inhibit Na(^+) and glucose transport in the proximal tubule
This leads to increased excretion of glucose, Na(^+), and water.
What clinical benefits have been observed with SGLT2 inhibitors in diabetic patients?
Lower glucose levels, improve albuminuria, kidney function, blood pressure, and cardiovascular disease
Heart failure improvement has also been noted in nondiabetic patients.
What adverse effects led to the use of angiotensin receptor blockers (ARBs) in heart failure management?
Some patients on ACE inhibitors had adverse effects
This prompted the exploration of ARBs as an alternative.
What is the role of neprilysin in the body?
Degrades endogenous vasoactive peptides
These peptides include natriuretic peptides, bradykinin, and adrenomedullin.
What is the effect of inhibiting neprilysin?
Increases levels of vasoactive peptides
This counters neurohormonal overactivation contributing to vasoconstriction and Na(^+) retention.
What is the combination of neprilysin inhibitor and ARB used for heart failure?
Sacubitril and valsartan (Entresto)
This combination is extensively used in patients with heart failure.
True or False: SGLT2 inhibitors have only been shown to lower glucose levels in diabetic patients.
False
They also improve other health parameters such as kidney function and cardiovascular health.
Fill in the blank: Neprilysin is a _______.
neutral endopeptidase
It plays a crucial role in degrading vasoactive peptides.
