Diuretics - Loop Flashcards
Where in the kidneys is blood filtered to form the filtrate?
1 - efferent arteriole
2 - afferent arteriole
3 - glomerulus
4 - juxtaglomerular
3 - glomerulus
Once the filtrate is formed from the glomerulus, what happens to the fluid as it move through the tubules and out of the collecting duct as urine?
1 - only glucose is reabsorbed
2 - Na+ and K+ only are reabsorbed
3 - lots of ions and fluids are reabsorbed
3 - lots of ions and fluids are reabsorbed
- H2O, ions (K+, Na+, Cl-)
- what is left is urine
Labels the parts of the renal tubules using the labels below:
1 - loop of henle
2 - distal convoluted tubule
3 - proximal tubule
4 - collecting duct
1 - proximal tubule
2 - loop of henle
3 - distal convoluted tubule
4 - collecting duct
Where are ions mainly re-absorbed in the renal system?
1 - loop of henle
2 - distal convoluted tubule
3 - proximal tubule
4 - collecting duct
3 - proximal tubule
- glucose, amino acids, ions, uric acid
- excretion of phosphate and H+
Water passively follows ion re-absorption in the distal tubules of the renal system, which ion specifically does it follow?
1 - Na+
2 - K+
3 -Cl-
4 - HCO3-
1 - Na+
- due to osmosis (H2O dilutes Na+ in blood)
What are diuretics?
1 - drugs that increase water, Na+ and Cl- excretion
2 - drugs that decrease water, Na+ and Cl- excretion
3 - drugs that increase water, K+ excretion
4 -drugs that decrease water, K+ excretion
1 - drugs that increase water, Na+ and Cl- excretion
- reduce fluid retention
Which of the following is not part of the loop of henle?
1 - thin descending loop of henle
2 - u-bend of henle
3 - thin ascending loop of henle
4 - thick ascending loop of henle
2 - u-bend of henle
- does not exist
Loop diuretic have their action by affecting the loop of henle. Specifically which part of the loop of henle do they have have their greatest effect?
1 - thin descending loop of henle
2 - thin ascending loop of henle
3 - thick ascending loop of henle
3 - thick ascending loop of henle
The thick ascending loop of henle is impermeable to what?
1 - Na+
2 - K+
3 - Cl-
4 - H2O
4 - H2O
The thick ascending loop of henle is impermeable to H2O. What type of channel is on the apical surface (closer to the lumen)?
1 - Na+/K+ ATPase
2 - Na+/K+/2Cl-
3 - Na+
4 - K+/Cl-
2 - Na+/K+/2Cl-
- moves 1 Na+ and K+ and 2 Cl- into the cells down the concentration gradient
The thick ascending loop of henle is impermeable to H2O. Na+/K+/2Cl- channels are present on the apical surface (closer to the lumen) that move 1 Na+ and K+ and 2 Cl-. On the basolateral side of the tubules there is a Na+/K+ ATPase. What does this do?
1 - exchanges 1 Na+ for 1K+
2 - exchanges 2 Na for K+ and 2Cl-
3 - exchanges 3 Na+ for 2 K+
4 - exchanges 2 Cl- for 1 Na+
3 - exchanges 3 Na+ for 2 K+
- requires ATP
- K+ and Cl- are able to leak back to into the lumen via leak channels
Through the reabsorption of Na+, K+ and Cl- an electrical gradient is generated allowing paracellular reabsorption of which 2 ions?
1 - Ca2+
2 - Cl-
3 - Mg2+
4 - Zinc
1 - Ca2+
3 - Mg2+
Which 2 of the following are the loop diuretics that we need to be aware of?
1 - Bumetanide
2 - Furosemide
3 - Indapamide
4 - Bendroflumethiazide
1 - Bumetanide
2 - Furosemide
Bumetanide and Furosemide are the loop diuretics that we need to be aware of. What is the mechanism of action of these drugs?
1 - inhibit Na+/K+ ATPase
2 - inhibit leaky K+/Cl- channels
3 - inhibit Na+ channels on arteries
4 - inhibit Na+/K+/2Cl- channels
4 - inhibit Na+/K+/2Cl- channels
- Na+, K+ and Cl- are excreted
- Ca2+ and Mg2+ are also excreted
- H2O follows the Na+
Which of the following is NOT increased in the excretion found in the urine?
1 - Na+
2 - K+
3 - Ca2+ and Mg2+
4 - glucose
5 - Cl-
4 - glucose
- remember ‘Loops Loose Calcium’
In addition to inhibiting the Na+/K+/2Cl- channels in the thick ascending loop of henle, loop diuretics Bumetanide and Furosemide have a second mechanism, what is this?
1 - vasoconstrict the efferent arteriole via prostaglandin release
2 - vasoconstrict the afferent arteriole via prostaglandin release
3 - vasoconstrict the efferent arteriole via prostaglandin release
4 - vasodilate the efferent arteriole via prostaglandin release
4 - vasodilate the efferent arteriole via prostaglandin release
- increases renal plasma flow
- increases eGFR
- this increases further loss of - Na+, K+, Cl-, Ca2+, Mg2+ and H2O
Loop diuretics, Bumetanide and Furosemide, have 2 mechanisms:
- inhibiting the Na+/K+/2Cl-
- vasodilate the efferent arteriole via prostaglandin release
Which drug class can cause a dampening of this prostaglandin release, and this attenuate the effect of loop diuretcis?
1 - Antiarrhythmics
2 - NSAIDs
3 - anti-hypertensives
4 - Anticoagulants
2 - NSAIDs
Which of the following is indicated alongside oxygen and nitrates in the treatment breathlessness in acute pulmonary oedema?
1 - Bumetanide or Furosemide
2 - Doxazosin
3 - Amlodipine
4 - Ramipril
1 - Bumetanide or Furosemide
- also though to dilate capacitance veins, reducing preload and improving cardiac function
Loop diuretics, Bumetanide and Furosemide are indicated in 2 of the following, which 2?
1 - chronic heart failure
2 - 1st line anti-hypertension
3 - adrenal insufficiency
4 - renal and/or liver failure
1 - chronic heart failure
4 - renal and/or liver failure
- BOTH can cause fluid overload
Which of the following is NOT an adverse effect of loop diuretics?
1 - hypotension
2 - low electrolyte state
3 - hyponatraemia
4 - hearing loss/tinnitus
5 - cardiac arrhythmias
5 - cardiac arrhythmias
- hypotension and low electrolyte state due to excretion
- hyponatraemia is most common, but if too much water is lost it can lead to hypernatraemia
Loop diuretics, Bumetanide and Furosemide are contradicted in which 2 of the following:
1 - severe hypovolemia
2 - severe dehydration
3 - peripheral oedema
4 - nephrotic syndrome
1 - severe hypovolemia
2 - severe dehydration
Loop diuretics, Bumetanide and Furosemide should be used with caution with all of the following except?
1 - hypokalaemia
2 - hyponatraemia
3 - glaucoma
4 - hepatic encephalopathy
3 - glaucoma
- low K+ can worsen hepatic encephalopathy and induce a coma
Patients with gout should avoid the chronic use of loop diuretics, Bumetanide and Furosemide, why?
1 - K+ inhibits uric acid formation
2 - K+ inhibits crystal formation
3 - low H2O increases concentration of uric acid
4 - increased uric acid reabsorption
4 - increased uric acid reabsorption
- low circulating fluids can increase uric acid re-absorption in proximal tubules
- hypovolaemic patients can therefore have gout attacks due to increased uric acid re- absorption
Can loop diuretics, Bumetanide and Furosemide, increase or decrease lithium levels?
- increases
- due to reduced excretion
Can loop diuretics, Bumetanide and Furosemide, increase or decrease the risk of toxicity of digoxin?
- increase risk of toxicity
- less is filtered out of the kidneys
Loop diuretics, Bumetanide and Furosemide, can increase ototoxicity and nephrotoxitiy of which drug due to lower excretion levels?
1 - Gentamicin
2 - Co-Amoxiclav
3 - Amlodipine
4 - Spironolactone
1 - Gentamicin
- common side effect of this drug, so if it is not being excreted then more will increase the risk of side effects
What is the most important to monitor in patients who are prescribed loop diuretics, Bumetanide and Furosemide?
1 - U&Es
2 - FBC
3 - eGFR
4 - LFTs
1 - U&Es
- important to monitor Na+, K+, Cl-, Ca2+ and Mg2+ levels
