Cardiac pharmacology Flashcards
Which cardiac drug is contraindicated in renal artery stenosis?
ACE inhibitors
Which drugs would you prescribe in angina?
Beta blockers
Calcium channel antagonists
Nitrates
Nicorandil
Which drugs would you prescribe in hypertension?
ACE inhibitors Beta blockers Calcium channel antagonists Diuretics Spironolactone
Which drug is described as the “potassium sparing diuretic”?
Spironolactone
Which drugs would you prescribe in cardiac failure?
ACE inhibitors
Beta blockers
Diuretics
Spironolactone
Which side effect must you be wary of when using diuretics?
Hypokalaemia
Which part of the nephron do thiazide diuretics act on?
Distal tubule
How do diuretics work?
Inhibit NaCl absorption - as a result, H2O and NaCl excreted in urine
Blood volume is reduced, and so MABP decreases
Why are diuretics particularly useful in oedema?
They reduce blood volume and reduce arterioles and venules, allowing reabsorption of fluid into capillaries
Which part of the nephron do loop diuretics act on?
Ascending limb of the loop of henle
Which are stronger - loop diuretics or thiazide diuretics?
Loop
Which drug would be prescribed first (according to SIGN guidelines) in heart failure?
ACE Inhibitor
Beta blocker
Which drug can cause the regression of left ventricular hypertrophy?
ACE inhibitor
How do nitrates work?
Venorelaxation - decrease preload, decrease SV, decrease myocardial O2 requirement by reducing workload of the heart
Also causes dilatation of collateral arteries - blood flow redirected to ischaemic areas
What effect does NO have on cGMP?
Stimulates the conversion of more GTP to cGMP which stimulates relaxation of vascular smooth muscle
Which nitrate can be given to patients for short-term symptom management and prophylaxis before exercise?
GTN
Which cardiac drug is it possible to develop tolerance to?
Nitrates
What is the most common side effect of nitrates?
Headaches
Which chemical conversion do ACE inhibitors prevent?
Angiotensin 1 to angiotensin 2
Why do ACE inhibitors cause an irritating dry cough?
They prevent the inhibition of bradykinin - a chemical which irritates the nerve endings
What drug are patients converted to if they experience an irritating dry cough with ACE inhibitors?
ARBs e.g. losartan
Where do ACE inhibitors have their greatest effect?
Angiotensin sensitive vascular beds e.g. in brain, heart kidney
What effects do ACE inhibitors have on the vasculature?
Cause both venous and arteriolar dilatation, reducing preload, afterload and total peripheral resistance
Other than dry cough, what is another adverse effect of ACE inhibitors initially?
Hypotension, especially in patients treated with diruetics
