Renal Pharmacology Flashcards
Describe the functions of the kidney. (12)
Regulatory - fluid balance, acid base balance, electrolyte balance
Excretory - waste product and drug elimination.
Endocrine - Renin, erythropoietin, prostaglandins.
Metabolism - vitamin D, insulin, morphine.
Describe carbonic anhydrase inhibitors. (4)
Uses
MoA
Adverse drug reactions
Used primarily in glaucoma and altitude sickness.
Keeps HCO3- in the filtrate.
Can cause acidosis.
Describe osmotic diuretics. (4)
MoA
Uses
Adverse drug reactions.
Sits in the filtrate to draw water into the filtrate.
Used in realised intracranial pressure
Can cause hypernatraemia due to excessive water loss.
Describe loop diuretics. (7)
MoA
Uses
Adverse drug reactions.
Blocks NKCC2 so extra loss of Na+ and H2O.
Used to treat oedema
Can cause hypokalaemia, alkalosis, and hypocalcaemia, ototoxicity, increased LDL, gout.
Describe thiazide diuretics. (8)
MoA
Uses
Adverse drug reaction
Blocks NaCl channels in the DCT causing increased Na+ and H2O delivery to the collecting duct.
Used to treat hypertension because vasodilator as well as diuresis.
Can cause hypokalaemia, alkalosis, and hypercalcaemia, gout, hyperglycaemia, increased LDL.
Describe aldosterone antagonists. (9)
MoA
Uses
Adverse drugs reactions.
Spironolactone inhibits the binding of aldosterone to the intracellular receptor, so Na+/K+ expression is not upregulated.
Used in heart failure, hypertension, and hyperadrenalism.
Hyperkalaemia, impotence, painful gynaecomastia.
Describe K+ sparing diuretics. (3)
MoA
Uses.
Direct inhibition of ENaC to keep Na+ in the filtrate.
Used only when there is hypokalaemia.
Describe two non-pharmacological diuretics. (5)
MoA
Alcohol - inhibits ADH release
Caffeine - increased GFR and decreased Na+ resorption.
Describe two ADH antagonists. (6)
MoA
Uses
Lithium - diuretic but not natriuretic. Inhibits ADH action. Used to treat bipolar disorder.
Tolvaptan - diuretic but not natriuretic. ADH antagonist. Used to treat hyponatramia.
Describe generic adverse drug reactions of drugs that act on the kidney. (8)
Hypovolaemia and hypotension - RAAS activation - AKI
Electrolyte disturbance - Na+, K+, Ca2+, Mg2+
Metabolic abnormalities - depends on drug - glucose levels esp
Anaphylaxis / photosensitivity rash etc - rare.
Describe the drug interactions with K+ sparing diuretics. (3)
ACEi - hyperkalaemia - arrhythmias.
Describe the drug interactions with loop diuretics. (10)
Aminoglycosides (eg gentamicin) - nephro- and ototoxicity.
Digoxin - hypokalaemia - increased digoxin binding - digoxin toxicity.
Steroids - increased hyperkalaemia risk
Lithium - reduced lithium levels
Describe the drug interactions with thiazide diuretics. (14)
Digoxin - hypokalaemia - increased digoxin binding - digoxin toxicity.
Beta blockers - hyperglycaemia, hyperlipidaemia, hyperuricaemia.
Steroids - increased hyperkalaemia risk.
Lithium - lithium toxicity
Carbamazepine - Hyponatraemia
Describe the uses of diuretics in hypertension. (4)
Thiazide - vasodilator and diuresis
Spironolactone
Loop if fluid overloaded
Describe the uses of diuretics in heart failure. (4)
Loop - symptom management
Spironolactone - reduces mortality
Describe the uses of diuretics in decompensated liver disease. (3)
Loop and spironolactone - treats low effective circulating volume even though fluid overloaded.
Describe the uses of diuretics in nephrotic syndrome. (4)
Loop - often v high doses
Thiazide
K+ sparing or K+ suppliments
Describe the uses of diuretics in chronic kidney disease. (5)
Loop and thiazide - decreased GFR in CKD leads to salt and water retention - alkalosis helpful but avoid K+ sparing diuretics in CKD.
Describe the process of diuretic resistance. (6)
Describe the end result of this. (2)
Describe the treatments for this. (3)
In cardiac failure there is less blood supply to the gut, so less loop diuretic is absorbed.
In CKD, there is less functional nephrons, so more filled / busy anion transporters.
In nephrotic syndrome, there is less albumin in the blood to carry it.
Causes gut oedema, which is bad because it means less can be absorbed anyway.
Lower salt intake, give furosemide IV, and find minimum inhibitory concentration.
Describe the two types of nephrotoxicity. (2)
Direct damage to the renal tubular cells.
Accumulation of drugs in blood due to renal impairment.
Name 3 nephrotoxic drugs. (3)
Aminoglycosides (gentamicin, vancomycin)
Aciclovir
NSAIDs
Describe 4 drugs that can cause renal dysfunction. (4)
ACEi
Diuretics
NSAIDs
Metformin
Describe the steps that need to be taken before prescribing new drugs to patients with CKD. (4)
Check with a pharmacist
Avoid neohrotoxins
Remember some drugs accumulate - morphine, statins, nitrofurantoin.
