3.2) Heart Failure Flashcards
Which 3 drug classes can induce the loss of urine?
-diuretic= increase production of urine
-natriuretic= loss of sodium in urine
-aquaretic= loss of water without electrolytes
Which medical conditions are diuretics useful in treating?
Oedema
Primary hypertension
Heart failure
Nephrotic syndrome
CKD
Chronic liver disease
What are some common adverse effects of diuretics?
Hypovolaemic and hypotension
AKI (in response to hypovolaemia- RAAS activated, when sustained causes renal injury)
Electrolyte disturbance (Na+, K+, Mg2+, Ca2+)
Metabolic abnormalities
Anaphylaxis (less common)
Where do thiazide/thiazide-like diuretics act? Mechanism of action?
Inhibit Na+/Cl- co-transporter in apical membrane of distal convoluted tubule—-reduced sodium and water reabsorption.
Adverse effects of thiazides may include?
Hyperuricaemia (gout)
Hyperglycaemia
Erectile dysfunction (mechanism unknown)
Increased LDL conc/ increased triglycerides
Hypercalcaemia
Hypokalaemia
Indicate some contraindications to thiazide diuretics
Addison’s disease (will contribute to hyponatraemia)
Hypercalcaemia
Hyponatraemia
Refractory hypokalaemia
Symptomatic hyperuricaemia
DDI with thiazides may include?
Alcohol
Amlodipine (increase risk of hypotension)
Give examples of thiazide and thiazide like diuretics
Thiazide= Bendroflumethiazide
Thiazide like= indapamide
Which type of diuretic acts on the NKCC2 transporter? Where in the nephron?
Loop diuretics
Acts on the thick ascending limb of the loop of henle
Give an example of a loop diuretic
Furosemide
Bumetanide
Adverse effects of loop diuretics include?
Dehydration
Hypotension
Hypokalaemia
Hyponatraemia
Hyperuricaemia (chronic treatment)
Arrhythmia
Tinnitus- otoxicity
Increased cholesterol and triglycerides
Contraindications to loop diuretics?
Hypokalaemia
Hyponatraemia
Gout
Hepatic encephalopathy
DDIs associated with use of loop diuretics include?
Aminoglycoside antibiotics ie gentamicin (increases risk of ototoxicity)
Digoxin/lithium (cause yellow/blurred vision—- excreted via kidneys therefore increased conc in plasma)
Give an example of a drug that directly blocks ENac channels— how does this effect fluid status?
Amiloride— potassium sparing drug
Reduces Na+ reabsorption in DCT and reduces K+ excretion— reduces water reabsorption
Adverse effects of amiloride?
Hyperkalaemia
Potential arrhythmia
Contraindications to utilising amiloride (potassium sparing) may include?
Addison’s disease, anuria, hyperkalaemia
DDIs with drugs like amiloride may include?
Other potassium sparing drugs (risk of hyperkalaemia)
ACEi/ARBs— reduce aldosterone therefore have same eventual effect
What is the mechanism of action of Spironolactone or eplerenone?
Mineralocorticoid receptor antagonist aka aldosterone antagonist
No increased expression of ENac channels, reduced sodium reabsorption
What is the drug class of spironolactone?
Potassium sparing drugs
What are some of the possible adverse effects of Spironolactone use?
Gynaecomastia— (binds to androgen receptors, increases peripheral conversion of testosterone to oestradiol— proliferation of breast tissue)
Hyperkalaemia
Severe cutaneous adverse reactions
What are some of the contraindications to using spironolactone?
Addison’s disease
Anuria
Hyperkalaemia
Indicate some of the DDIs associated with Spironolactone
Alcohol
Amiloride (also potassium sparing, different mechanism)
ACEi
ARBs
How do carbonic anhydrase inhibitors work?
Prevent absorption of HCO3- in the proximal convoluted tubule— increase urinary excretion bound to Na+
Give an example of an osmotic agent
How does this work?
Mannitol
Osmotic agent draws water into the nephron lumen causing a reduced intracellular volume.
