Oedema + vascular disease Flashcards
What is the MOA of diuretics?
Blocks sodium reabsorption across nephron, INC urine output by kidneys
Loop diuretics
- Bumetanide (most potent)
- Furosemide (most gout)
- Torasemide (MSK pain)
Thiazide and related diuretics
- Bendroflumethiazide
- Chlortalidone (long HL - alt days)
- Indapamide (less aggravation of diabetes)
- Metolazone (for severe RI) (MHRA: caution switching brands)
Aldosterone antagonist diuretics
- Spironolactone (for liver ascites)
- Eplerenone (For post acute MI)
Potassium sparing diuretics
- Amiloride
- Triamterene (blue urine)
Osmotic diuretics
Mannitol (for: cerebral oedema, raised intra-occular pressure)
What are the sick day rule for diuretics?
STOP - Fluid loss = RED plasma volume → RED blood flow to kidneys → RED eGFR
What are the consequences of excessive diuretics doses?
Too much fluid loss. RED plasma volume → low blood pressure and cause hypervolemia (low blood volume)
What is the MOA of loop diuretics?
Block sodium potassium chloride co-transporter on ascending loop of henle
- Onset: 1H
- Duration: 6h
What is the indication of loop diuretics?
- Fluid build up/oedema in HF
- Last line: Resistant hypertension
What is the caution when taking loop diuretics?
Exacerbates diabetes + gout
What are the side effects of loop diuretics?
Electrolyte imbalance (RED Na+, K+, Cl-, Mg2+, Ca2+)
Ototoxicity - tinnitus + deafness
Acute urinary retention
- Caution: enlarged prostate
What are the interactions of loop diuretics?
Aminoglycoside (gentamicin) → ototoxicity
- Counselling: separate doses by long periods
Aminoglycoside (gentamicin) → nephrotoxicity
What is the MOA of thiazide + related diuretics?
Block sodium chloride transporter on proximal distal convoluted tubule
- Onset: 1-2H
- Duration: 12-24h
What is the indication of thiazide + related diuretics?
- Fluid build up/oedema in HF
- Last line: Resistant hypertension
Can you use thiazide + related diuretics in renal impairment?
Ineffective in severe RI (except metolazone)
What are the cautions when taking thiazide + related diuretics?
Exacerbates diabetes + gout
- Indapamide: least effect
What are the side effects of thiazide + related diuretics?
Electrolyte imbalance (RED Na+, K+, Cl-, Mg2+, Ca2+)
Diarrhoea
Impotence
Skin reactions
- MHRA: hydrochlorothiazide - risk of non-melanoma skin cancer long term use
- Counselling: Report new/changed skin lesions, regular checks. Limit skin + UV exposure + use sun protection
High LDL cholesterol + triglycerides
What are the interactions of thiazide + related diuretics?
Hypotension
- Antihypertensives
- Antidepressants
- Nitrate
- Phosphodiesterase type 5 inhibitor
Hypokalaemia
- Digoxin toxicity
- Beta 2 agonist
- Anti-arrhythmic
Hyponatraemia
- Lithium toxicity → AKI
NSAIDs + thiazides → AKI
What is the MOA of potassium sparing diuretics?
- Conserves K+
- Blocks sodium channels in late distal convoluted tubule in collecting duct
What is the indication of potassium sparing diuretics?
Adjunct: potassium conservation w loop + thiazides
- Preferred over supplements
What are the side effects of potassium sparing diuretics?
Hyperkalaemia, Hyponatraemia
- Counselling: urine blue in some lights (triamterene)
What are the interactions of potassium sparing diuretics?
Hyperkalaemia
- ACEi/ARB Aldosterone antagonist
- Heparin
- NSAID
- K supplement
- Trimethoprim
What is the MOA of aldosterone antagonists?
- Blocks aldosterone
- Acts on NA+ channels from late distal convoluted tubule to collecting duct
What are the indications of aldosterone antagsonists?
Adjunct: HF
- Preferred over supplements
Spironolactone:
- Resistant hypertension
- Liver ascites
What are the side effects of aldosterone antagonists?
HypERkalaemia
- ACEi/ARB Aldosterone antagonist
- Heparin
- NSAID
- K supplement
- Trimethoprim
What are the types of PVD?
either occlusive or vasospastic
What is occlusive PVD (peripheral arterial disease)?
Atherosclerosis narrows peripheral arteries in limbs, usually the legs
- Causes leg pain or aches when walking
- Disappears after a few minutes of resting - intermittent claudication
What is vasospastic PVD?
Blood vessels temporarily spasm, restricting blood flow to fingers + toes
What is the treatment for peripheral arterial disease?
Secondary prevention: high intensity statin AND low dose aspirin
What is the treatment for vasospastic PVD?
Nifedipine
- Stop smoking
- Avoid cold + stress
