In what instances are carbonic anhydrase inhibitors used? How do they work? Why arent they used more frequently?
- Used for glaucoma
- Not used due to risks of metabolic acidosis and hypokalaemia
- Acts on PCT to prevent action of carbonic anhydrase
In what instances are osmotic diuretics used? How do they work? Why arent they used more frequently?
- Used in cerebral or pulmonary oedema
- not used as causes excessive water loss and hypernatraemia
- Act to increase osmotic gradient in renal tubules
How do ADH antagonists work?
Works by preventing AQP2 from being placed on cell membrane, preventing the water from being taken out of the tubule
What are the 5 types of diuretics currently used?
K sparing (Aldosterone antagonists (Spironolactone)/ENaC blockers (Amiloride))
Carbonic anhydrase inhibitors
Give an example loop diuretic. What is its MoA? What is its indications?
- acts on NKCC2 on thin ascending loop of henle.
- Risk of hypokalaemia
- indications - HF, liver failure
Give an example thiazide diuretic. What is its MoA? What are its ADRs? Indications? DDI?>
e.g. - chlorothiazide
MoA - Acts on NaCl symporter in DCT. Promotes Ca reabsorption
ADR - hypokalaemia, hypercalcaemia, hyperuricaemia, ED
Indications - HF, hypertension
DDI - Beta blockers, digoxin, steroids all increase risk of ADRs
Give an example K sparing diuretic. MoA? DDI?
e.g. - amiloride
MoA - ENaC in DCT and CD.
DDI - ACE inhibitor increases risk of hyperkalaemia
Give example aldosterone antagonists. MoA? Indications? ADR?
e.g. - spironolactone
MoA - Inhibition of aldosterone results in less NaKATPase and ENaC synthesis
ADR - hyperkalaemia, gynocomastia
Indications - HF, hypertension, liver failure, hyperaldosteronism e.g. Conns syndrome
What drugs would you use for heart failure?
Loop or thiazide diuretic.
ACEi and/or Beta blockers
What drugs would you use for hypertension?
Thiazide or aldosterone antagonists
ACEi and/or CCBs
What drugs would you use for liver failure?
aldosterone antagonist and loop diuretic
What are 4 physiological functions of the kidney?
Regulatory, Excretory, Endocrine, Metabolism
What are the regulatory functions of the kidney?
Fluid balance, acid base balance, electrolyte balance
What are the excretory functions of the kidney?
Waste products, drug elimination
What are the endocrine functions of the kidney?
Renin-angiotensin-aldosterone, erythropoetin, prostaglandins
What are the metabolic functions of the kidney?
Vitamin D, polypeptides (insulin and PTH)