Cardiovascular drugs Flashcards
What type of diuretic is furosemide?
Loop diuretic (inhibits salt and water reabsorption from ascending limb of loop of Henle)
When should furosemide be used?
Pulmonary oedema due to LVF, chronic heart failure, oedema, resistant HTN
Important furosemide interactions?
NSAIDs may reduce effect of drug
K+ loss leads to digoxin toxicity
Increased risk of ototoxicity with aminoglycosides, colistin and vancoymcin
Increased risk of nephrotoxicity with aminoglycosides
Increased risk of toxicity with lithium
What type of diuretic is bendroflumethiazide?
Thiazide diuretic - inhibits Na+ and water reabsorption in distal convoluted tubule
3 states/conditions thiazide diuretics should be avoided?
Refactory hypokalaemia, hyponatraemia and hypercalcaemia Symptomatic hyperuricaemia Addison's disease Sever liver disease Gestational HTN
Bendroflumethiazide administration alongside what can lead to arrhythmias?
Terfenadine, as diuretics can cause electrolyte disturbances –> more at risk of arrhythmias
What type of drug can increase K+ loss with thiazide diuretics?
Corticosteroids
How do thiazide diuretics work to reduce HTN?
Initial decrease in cardiac output due to reduced fluid volume but long term effect is due to reduced total peripheral resistance
What type of diuretic is spironolactone?
K+ sparing diuretic and aldosterone antagonist
How does spironolactone produce its effects?
Competitive inhibitor of aldosterone and acts on distal portion of renal tubule thereby increasing NA+ and H2O excretion and reducing K+ excretion
Indictations for spironolactone?
Oedema and ascites in liver cirrhosis, malignant ascites, nephrotic syndrome, oedema in congestive heart failure, resistant HTN, primary hyperaldosteronism
Contra-indications for spironolactone?
Addison’s disease, hyperkalaemia, anuria
What drugs can increase K+ levels and potentiate spironolactone?
ACE-i, NSAIDs, ARBs, cyclosporine, tacrolimus, potassium salts
Which diuretics are more effective: loop or thiazide?
Loop diuretics are more effective
Examples of cardioselective (B1) B-adrenoreceptor blockers?
Atenolol, propanolol, carvedilol
Effects of beta-blockers?
Decrease HR and force, reduce renin production by kidneys, decrease conduction in heart (anti-arrhythmic effect)
Which drugs may reduce the antihypertensive effects of beta blockers?
Decongestants and NSAIDs
What drug when given with beta blockers may mask symptoms of hypoglycaemia?
Insulin
What class of drugs are diltiazem and amlodipine?
Ca2+ channel blockers
How do calcium channel blockers work?
Selectively reduce calcium entry into vascular smooth muscle and myocardial cells thus lowering intracellular calcium so less activation of contractile proteins resulting in coronary artery dilation and therefore increased oxygen supply
Indications for diltiazem?
Angina, HTN, dysrrhythmias
Which drug is known to undergo extensive 1st pass metabolism and which drug undergoes no 1st pass metabolism?
Diltiazem
and
Isosorbide Mononitrate
Why is it important not to suddenly withdraw diltiazem?
May exacerbate angina
Examples of ACE inhibitors?
Ramipril, lisinopril
What do ACE inhibitors prevent?
Conversion of Angiotensin I to Angiontensin II and the downstream effects of this