Oedema And Vascular Disease Flashcards
When do you take diuretics?
In the morning to avoid sleep disruption
What are the loop diuretics?
Bumetanide - most potent
Furosemide - gout
Torasemide - MSK pain
What are the thiazide diuretics?
Bendroflumethiazide
Cyclopenthiazide
What are the thiazide like diuretics?
Chlortalidone - long half life
Indapamide- less aggravation of diabetes
Metolazone - still works in severe renal failure
Xipamide
What are the potassium sparing diuretics?
Amiloride
Triamterene - blue urine
What are the aldosterone antagonists?
Spironolactone - ascites liver failure
Eplerenone - post MI
What are the osmotic diuretics?
Mannitol - cerebral oedema
What are the carbonic anhydrase inhibitors?
Acetazolamide - glaucoma
What is the mechanism of action of diuretics?
Increase ursine output by the kidneys
Promotes diuresis by inhibiting sodium reabsorption at different parts of the renal tubular system (nephron)
How do the loop diuretics work?
Inhibits the Na+/K+/Cl- co-transporter in ascending limb of loop of henle
How long does it take for loop diuretics to work?
1 hour onset
6 hour duration
What are the side effects of loop diuretics?
Ototoxicity
Acute urinary retention - too rapid diuresis, caution in BPH
Hyperglycaemia in diabetes
Hyperuricaemia in gout
Hypo K+, Na+, Cl-, Mg2+
Hypo Ca2+
What is the heart failure dose for loop diuretics?
BD, last dose at 4pm
20-40mg OM - furosemide doses
What loop diuretics are used for resistant hypertension?
Bumetanide - most potent
Torasemide
Furosemide
How do thiazides and thiazide like diuretics work?
Inhibits Na+/Cl- transporter in distal convoluted tubule
How long does it take for thiazides and thiazide-like diuretics to work?
1-2 hour onset
12-24 hour duration
What are the side effects of thiazide and thiazide like diuretics?
GI disturbances
Impotence
High LDL/triglycerides
Hyperglycaemia
Hyperuricaemia
Hypo K+, Na+, Cl-, Mg2+
Hyper Ca2+
Ineffective if eGFR <30 ml/min except metolazone
What is the dose of thiazide and thiazide like diuretics in heart failure?
5mg OM
What is the dose of thiazide and thiazide like diuretics in hypertension?
2.5mg OM
What is the mechanism of action of potassium sparing diuretics?
Promotes urination without the loss of potassium by inhibiting sodium channels in the distal convoluted tubule
Weak diuretics used as adjunct to loop and thiazides
When are triamterene and amiloride used?
Preferred over potassium supplements in counteracting hypokalaemia
What are the side effects of potassium sparing diuretics?
Hyperkalaemia
What causes hyperkalaemia when used concomitantly with potassium sparing diuretics?
ACEi/ARB, K+ supplements, aldosterone antagonists
What is the mechanism of action of aldosterone antagonists?
Inihibits aldosterone which causes sodium reabsorption via the Na+/K+/H+ co-transporter
Less potassium and hydrogen ions are exchanged for sodium and therefore less lost to the urine
What are the side effects of spironolactone?
Gynaecomastasia
Hypertrichosis
Change in libido
Hyperkalaemia, hyperuraemia, hyponatraemia
What causes severe hyperkalaemia when used with aldosterone antagonists?
Potassium sparing diuretics, potassium supplements, ACEi/ARBs
What is the MHRA warning for aldosterone antagonists and ACEi/ARBs?
In heart failure - risk of fatal severe hyperkalaemia
Monitoring of blood electrolytes is essential
What is the mechanism of action of osmotic diuretics?
Inhibits sodium and water reabsorption by increasing the osmolarity (solute concentration) of blood and renal filtrate
Act on parts of nephron that are water permeable
When is mannitol used?
Cerebral oedema
High intracranial pressure
What is used for simple gravitational oedema in the elderly?
Low dose diuretic
Not for long term use
What is peripheral vascular disease?
Occlusive - peripheral and arterial disease
Aspirin 75mg daily and statin as secondary prevention or cardiovascular events
Vasospastic - reynauds
Nifedipine used to treat Reynauds
