Cardiovascular Flashcards
what type of drug is furosemide?
loop diuretic
how do loop diuretics work?
Inhibit reabsorption of Na+, K+ and Cl- (and therefore water) from the ascending limb of the loop on Henle in the renal tubule
also dilate capacitance veins - very useful in heart failure. reduces preload on heart and improves contractile function
what are the indications to take furosemide?
oedema, resistant hypertension, heart failure
what are the contraindications to taking furosemide?
dehydration
hypokalaemia/ hyponatraemia
gout - inhibit uric acid excretion
what are the side-effects of furosemide?
dehydration + hypovolaemia
any low electrolyte state
hearing loss/ tinnitus
what are the interactions with furosemide?
any drug excreted by the kidney e.g. lithium, digoxin
aminoglycosides - increase oto/nephrotoxicity
what type of drug is spironolactone?
potassium sparing diuretic
how do potassium sparing diuretics work?
act on distal convoluted tubules
inhibit Na uptake (and therefore water)
this causes potassium retention
often used in conjunction with other diuretics as weak on its own
what are the indications to take spironolactone?
oedema, hypokalaemia as a result of other diuretics
what are the contraindications to taking spironolactone?
Hyperkalaemia, anuria and Addison’s disease
what are the side effects of spironolactone?
GI upset, hypotension, dizziness, electrolyte disturbance
what are the interactions with spironolactone?
other potassium elevating drugs
digoxin, lithium (affects clearance of these)
what type of drug is bendroflumethiazide?
thiazide diuretic
how do thiazide diuretics work?
inhibit the sodium-chloride transporter in the distal tubule and therefore water. this lowers potassium as sodium is retained by the aldosterone pump
what are the indications to take thiazide diuretics?
Hypertension
what are the contraindications to taking thiazide diuretics?
hypokalaemia/ hyponatraemia
gout
what are the side effects of thiazide diuretics?
hyponatraemia/ hypokalaemia
this may then lead to cardiac arrhythmia
inc plasma glucose
impotence in men
what are the interactions with thiazide diuretics?
NSAIDs reduce effect
other potassium lowering drugs
other hypotensive drugs - greater effect
why are thiazides particularly useful in hypertension?
main adverse effects of thiazides is hypokalaemia,
main adverse effects of ACE inhibitors and ARBs is hyperkalaemia.
synergistic blood pressure lowering effect: thiazides activate the renin–angiotensin system, while ACE inhibitors/ARBs block it.
combination of a thiazide and an ACE inhibitor/ARB is very useful in practice to improve BP control and to maintain neutral potassium balance.
what type of drug is atenolol?
beta blocker
how do beta blockers work?
B1 - block receptor to reduce force and contraction speed of the heart. this reduces ischaemia by reducing cardiac workload
also lower BP by renin secretion inhibition
what are the indications to take beta blockers?
IHD CHF AF SVT hypertension
what are the contrindications to taking beta blockers?
Asthma - can cause bronchospasm (act on B2 receptors)
COPD (only use B1 selective e.g. atenolol, bisoprolol rather than non selective e.g propanolol)
heart block
haemodynamic instability
what are the side effects of beta blockers?
fatigue, cold extremities, headache, GI upset, sleep disturbance, impotence in men
what are the interactions with beta blockers?
calcium channel blockers - can cause heart failure, bradycardia and asystole
theophylline decreases effect
how do calcium channel blockers work?
decrease Ca2+ entry into vascular and cardiac cell
relaxation and vasodilation in arterial smooth muscle
reduce myocardial contractility, suppress cardiac conduction
Reduced cardiac rate, contractility and afterload reduce myocardial oxygen demand, preventing angina
what are the two types of calcium channel blocker?
Dihydropyridines (amlodipine and nifedipine) - relatively selective for the vasculature
Non-dihydropyridines (verapamil, diltiazem) are more selective for the heart.
what are the indications to take calcium channel blockers?
Prophylaxis and treatment of STABLE angina, hypertension (amplodipine), supraventricular arrhythmia (diltazem)
what are the contraindications to taking calcium channel blockers?
poor left ventricular function - lead to HF
AV nodal conduction delay - may provoke complete heart block
unstable angina
severe aortic stenosis
what are the side effects of calcium channel blockers?
ankle swelling, flushing, headache, palpitations,
constipation, bradycardia, heart block and cardiac failure
what are the interactions with calcium channel blockers?
β-blockers - together may cause heart failure, bradycardia, and even asystole.
what type of drug are Ramipril, lisinopril and perindopril?
ACE inhibitor
how do ACEi work?
prevent the conversion of angiotensin I to angiotensin II
Angiotensin II is a vasoconstrictor and stimulates aldosterone secretion.
Blocking its action reduces peripheral vascular resistance (afterload), which lowers blood pressure
works particularly well on renal arteries so good for CKD
what are the indications to take ACEi?
hypertension
CHF
IHD
diabetic neuropathy and CKD
what are the contraindications to taking ACEi?
AKI, renal artery stenosis
what are the side effects of taking ACEi?
hypotension, persistent dry cough, renal failure, angioedema and anaphylaxis
what are the interactions with ACEi?
potassium-elevating drugs e.g. potassium sparing diuretics
NSAID - increase risk of renal failure
what type of drug is losartan?
Angiotensin receptor blockers (ARB)
how do Angiotensin receptor blockers work?
similar effect to ACEi - block action of angiotensin II on receptor
what are the indications to take Angiotensin receptor blockers?
hypertension CHF IHD diabetic neuropathy and CKD (used when ACEi are not tolerated)
what are the contraindications of taking Angiotensin receptor blockers?
pregnancy, breastfeeding
renal artery stenosis/ AKI
what are the side effects of Angiotensin receptor blockers?
hypotension, hyperkalaemia, renal failure
less likely to cause a dry cough than ACEi
what are the interactions with Angiotensin receptor blockers?
other potassium elevating drugs
NSAIDs - causes renal failure
give 2 examples of nitrate drugs
isosorbide mononitrate, glyceryl trinitrate
how do nitrates work?
Dilates blood vessels (is converted to NO which activates dilation)
reduce cardiac work and myocardial oxygen demand, relieving angina and cardiac failure
what are the indications to take nitrates?
ACS/angina
what are the contraindications to taking nitrates?
aortic stenosis, haemodynamic instability
what are the side effects of taking nitrates?
Postural hypotension, tachycardia, throbbing headache, dizziness, tolerance
what are the interactions with nitrates?
phosphodiesterase inhibitors (sildenafil) - these enhance the effects of nitrates antihypertensive medication - can cause hypotension
what type of drug is digoxin?
cardiac glycoside
how does digoxin work?
reduces HR ( increased vagal tone (reduces conduction at AV node)) , increases force of contraction
what are the indications to take digoxin?
AF, heart failure
what are the contraindications to take digoxin?
heart block, arrhythmia, renal failure (excreted by kidneys), electrolyte imbalance ( makes toxicity more likely)
what are the side effects of digoxin?
bradycardia, gastrointestinal disturbance, rash, dizziness and visual disturbance
has low therapeutic index - toxicity likely. arrhythmias likely in toxicity
what are the interactions with digoxin?
diuretics increase the chance of toxicity
Amiodorone, calcium channel blockers, spironolactone and quinine can all increase the plasma concentration of digoxin
what type of drug is amiodarone?
anti-arrhythmic
how does amiodarone work?
Increases duration of ventricular and atrial muscle action by inhibiting Na,K-activated myocardial adenosine triphosphatase – this results in decrease in heart rate and in vascular resistance
what are the indications to take amiodarone?
any tachyarrhythmia (AF, SVT, VT, VF)
what are the contraindications to taking amiodarone?
hypotension, heart block, thyroid disease
what are the side effects of amiodarone?
hypotension, pneumonitis, heart block, hepatitis, photosensitivity, thyroid abnormalities
has a very long half life so symptoms may take a long time to settle after stopping the drug
what are the interactions with amiodarone?
lots
increases plasma concentrations of digoxin, diltiazem and verapamil (increase the risk of bradycardia, AV block and heart failure.)
what type of drug is aspirin?
anti-platelet
how does aspirin work?
irreversibly inhibits cyclooxygenase (COX) to reduce production of the pro-aggregatory factor thromboxane from arachidonic acid, reducing platelet aggregation and the risk of arterial occlusion
what are the indications to take aspirin?
ACS or acute ischaemic stroke
prevention of thrombotic arterial events
AF
(mild pain and fever)
what are the contraindications to taking aspirin?
under 16s - can develop Reye’s syndrome
3rd trimester of pregnancy
peptic ulceration, gout
what are the side effects of aspirin?
GI irritation, ulceration, and haemorrhage
tinnitus
bronchospasm (allergy to NSAIDs)
bruising
what are the interactions with aspirin?
other antiplatelets ( clopidogrel, dipyridamole) and anticoagulants (e.g. heparin, warfarin) - increase the effect
what type of drug is clopidogrel?
antithrombotic
how does clopidogrel work?
prevents platelet aggregation and therefore risk of arterial occlusion
what are the indications to take clopidogrel?
treatment of ACS
prevent occlusion of stents
prevention of thrombotic arterial events eg in stroke, AF
post MI
what are the contraindications to taking clopidogrel?
active bleeding
surgery
hepatic/renal impairment
what are the side effects of clopidogrel?
bleeding
GI upset
thrombocytopaenia
what are the interactions with clopidogrel?
effect reduced by P450 inhibitors e.g. omeprazole, ciprofloxacin,
other antiplatelet/anticoagulation drugs
what type of drug is heparin?
Tissue plasminogen activator
how does heparin work?
inhibit thrombin and factor X - help prevent clot formation
what are the two types of heparin?
Unfractionated heparin (UFH) activates antithrombin that, in turn, inactivates clotting factor Xa and thrombin.
Low molecular weight heparins such as dalteparin and enoxaparin have a similar mechanism of action but preferentially inhibit factor Xa.
Low molecular weight heparins have a more predictable effect and, unlike UFH, do not usually require laboratory monitoring. Consequently, LMWHs are now preferred in most indications
what is fondaparinux?
Fondaparinux is a synthetic compound that is similar to heparin. It inhibits factor Xa only. It appears to have similar efficacy to LMWH and has become the anticoagulant of choice in the treatment of ACS in many hospitals in the UK.
what are the indications to take heparin?
VTE
ACS
what are the contraindications to taking heparin?
clotting disorders, hypertension, surgery/trauma
renal impairment - can cause build up of drug
what are the side effects of heparin?
bleeding (lower in LMWH/ fondaparinux)
thrombocytopaenia
what are the interactions with heparin?
antithrombotics - risk of bleeding
how does warfarin work?
inhibits vitamin K epoxide reductase, preventing reactivation of vitamin K and coagulation factor synthesis.
what are the indications to take warfarin?
DVT/PE
prevent clots in AF + heart valve replacement
(not used in arterial thrombosis e.g. MI)
what are the contraindications to taking warfarin?
bleeding risk
liver disease (reduced metabolism)
pregnancy
what are the side effects of taking warfarin?
bleeding
what are the interactions with warfarin?
P450 inhibitors (fluconazole, macrolides) increase bleeding risk
P450 inducers (phenytoin, carbamazapine) increase clotting risk
has a very low therapeutic index
antibiotics that kill gut flora that produce vitamin K - increases bleeding risk
what class of drug is rivaroxaban?
Novel anti-coagulants
how does rivaroxaban work?
Direct inhibitor of activated factor X
what are the indications to take rivaroxaban?
Prophylaxis of venous thromboembolism (after hip/knee replacement surgery), treatment of DVT and PE, prophylaxis of DVT, PE, stroke, systemic embolism in AF; given in combination with clopidogrel/aspirin after acute coronary event
what are the contraindications to taking rivaroxaban?
Active bleeding, significant risk of major bleed, (in acute coronary syndrome – previous stroke/TIA)
what are the side-effects of rivaroxaban?
Nausea, vomiting, diarrhoea, constipation, dyspepsia, abdo pain, hypotension, dizziness, headache, renal impairment, haemorrhage, pain in extremeties, pruritus, rash
what are the interactions with rivaroxaban?
Increased risk of haemorrhage with other anticoagulants
P450 inducers and inhibitors (same as warfarin)
name two different statins
simvastatin, atorvastatin
how do statins work?
reduce serum cholesterol by inhibiting HMG CoA reductase. This decreases cholesterol production by the lover and increases clearance from the blood.
what are the indications to take a statin?
prevention of CVD if risk of cardiac event >20%
treatment of hyperlipidaemia
what are the contraindications to taking a statin?
hepatic impairment, renal impairment, pregnant/breastfeeding
what are the side effects of statins?
headache, GI upset, muscle aches, raise in liver enzymes
what are the interactions with statins?
The metabolism of statins is reduced by cytochrome P450 inhibitors (amiodarone, diltiazem, itraconazole, macrolides) - increased risk of side-effects
amlodipine has similar effect