Cardiovascular Drugs Flashcards
What are ACEi and what are they indicated in?
Angiotensin Converting enzyme Inhibitor
- HTN
- Chronic HF
- Ischaemic Heart Disease
- Diabetic Nephropathy
- CKD
What is the MOA of ACEi in HTN?
The dug blocks the action of ACE to prevent the conversion of angiotensin I to angiotensin II.
This then inhibits aldosterone secretion causing vasodilation.
This reduces the peripheral vascular resistance (afterload) hence lowering BP.
What is the MOA of ACEi in Chronic HF?
The drug blocks the action of ACE to prevent the conversion of angiotensin I to angiotensin II.
This then reduces aldosterone secretion; promoting Na 2+ and H2O excretion which can help reduce venous return (preload)- good for treating HF
What is the MOA of ACEi in CKD?
When the BP is lowered, this causes the efferent glomerular arterioles to dilate; which reduces the intraglomerular pressure to slow the progression of CKD.
What are the side effects of ACEi?
- Hypotension
- Dry cough
- Hyperkalaemia- due to lower aldosterone level that promotes K+ retention.
RARE:
- Angioedema
- allergies
Who are ACEi contraindicated in?
- Renal artery stenosis
- Acute kidney injury
- Pregnant/ breastfeeding
What other drugs does ACEi interact with?
Due to risk of hyperkalaemia, avoid prescribing with other POTASSIUM-ELEVATING DRUGS, including K supplements and potassium-sparing diuretics, except under specialist advice for advanced HF
ACEi and NSAID together particularly increase the risk of nephrotoxicity
What is Aspirin and what is it Indicated in?
Aspirin is a antiplatelet drug and an NSAID.
Indicated in:
- ACS
- Acute Ischaemic Strole
- Stroke prevention
What is the MOA of Aspirin?
Irreversibly inhibits cyclooxygenase (COX) which reduces the production of thromboxane (pro-aggregatory factor) from arachidonic acid.
This then inhibits platelet aggregation and the risk of arterial occlusion.
What are the main side effects of Aspirin?
- dyspepsia
- peptic ulcer
- haemorrhage
- Allergies- bronchospasm
- Tinnitus
What could happen if a patient overdosed on Aspirin?
Overdose – life-threatening:
- Hyperventilation
- Hearing changes
- Metabolic acidosis
- Confusion
- Convulsions
- CV collapse
- Respiratory arrest
What is Aspirin contraindicated in?
- Not given if <16y
- aspirin hypersensitivity
- 3rd trimester of pregnancy
- Peptic ulceration (give PPI)
- gout (may trigger acute attack)
What drugs does Aspirin interact with?
- antiplatelet agents – can lead to increased risk of bleeding (e.g. heparin, warfarin)
- NSAIDs – ulcers (give PPI)
What kind of drug is Clopidogrel?
Antiplatlet drugs; ADP-receptor antagonist
What is Clopidogrel indicated in?
- ACS
- Prevent occlusion of coronary artery stents
- Thrombotic arterial events in pts with CV, cerebrovascular and PAD
- TIA prevention, without AF for stroke prevention
What is the MOA of Clopidogrel?
Clopidogrel prevents platelet aggregation by irreversibly binding to adenosine diphospate (ADP) receptors found on the surface of platelets
As this process is independent of COX pathway so it has a synergistic action with aspirin.
What are the side effects of clopidogrel?
Common:
- Bleeding
- Dyspepsia
- Abdominal pain
- Diarrhoea
- Haemorrhage
Rare = thrombocytopenia
What is clopidogrel contraindicated in?
- active bleeding
- stop taking 7 days before surgery
CAUTION:
- renal and hepatic impairment
What are the key interactions of Clopidogrel?
Efficacy may be reduced by cytochrome P450 (CYP) inhibitors as (clopidogrel is a pro-drug that requires metabolism by CYP enzymes) e.g:
- Omeprazole
- Ciprofloxacin,
- Erythromycin
- Some antifungals
- Some SSRIs
Co-prescription with the following increase bleeding risk:
- Other antiplatelet drugs
- Anticoagulants
NSAIDs
- If gastroprotection with PPI required, prescribe lansoprazole or pantoprazole over omeprazole
What are Statins Indicated in?
- Prevention of CV events
- Hyperlipidaemia
What is the MOA of Statins?
In the liver, statins inhibit 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG CoA) reductase which reduces serum cholesterol levels.
- Increase clearance of LDL from the blood to reduce LDL levels.
- Indirectly reduce triglycerides and slightly increase HDL-cholesterol levels ?? Check if correct
^^Through these effects, slow the atherosclerotic process and may even reverse it.
What are the main side effects of statins?
Most common:
- headache
- GI disturbance
More Severe:
- muscle aches
- Myopathy
- Rhabdomylosis
Rare:
- rise in liver enzymes (ALT)
Who are statins contraindicated in?
Caution:
- existing hepatic impairment
- renal impairment
Avoid:
- pregnancy
- breastfeeding
- Hypothyroidism increases the risk of myositis with statins.
What other drugs does Statins interact with?
Metabolism of statins is reduced by:
- CYP inhibitors e.g. amiodarone, diltiazem, itraconazole, macrolides
- Protease inhibitors lead to the accumulation of statin in the body. Patient is at risk of adverse effects
- Amlodipine
- Grapefruit AVOID if on Simvastatin OR Atorvostatin
What are the main indications of Digoxin?
To reduce ventricular rate in AF and atrial flutter
- BUT BB or non-DHP CCBs usually more effective
In severe HF, it is used at an earlier stage in pts with co-existing AF. It’s an option in pts who are already taking an:
- ACEi
- BB
- AA or ARB
What is the MOA of Digoxin?
- Negatively chronotropic
- Positively inotropic
In AF and atrial flutter, DIgoxin reduces conduction at the AVN.
This prevents impulses from being transmitted to ventricles to reduce the ventricular rate.
- Therapeutic effect arises mainly via an indirect pathway involving increased vagal (parasympathetic) tone (thus tends to be lost during stress and exercise so rarely used on its own for AF, although may be an option in sedentary pts)
- In heart failure, Digoxin inhibits NA/K ATPase pumps on myocytes which causes Na+ to accumulate in the cell causing Ca accumulation in cell which increases contractile force.
What are the main side effects of Digoxin?
- Bradycardia
- GI disturbance
- Rash
- Dizziness
- Visual disturbance (blurred or yellow vision)
Whom is Digoxin contraindicated in?
Those with conduction abnormalities:
- heart block
Ventricular arrhythmias
reduce dose in renal failure.
Certain electrolyte abnormalities increase the risk of its toxicity:
- Hypomagnesaemia
- Hypercalcaemia
- Hypokalaemia- digoxin competes with K+ to bind NA/K ATPAase pump, meaning low serum K so, reduced competition allowing for enhanced effects of digoxin.
What are the key drug interactions of Digoxin/
- Loop and thiazide diuretics cause hypokalaemia, so can increase risk of digoxin toxicity.
Plasma concentration of digoxin can be increased by:
- Amiodarone
- CCBs
- Spironolactone
- Quinine
which Increases risk of toxicity
Give examples of Short-acting Nitrates and its indication?
Short acting nitrate (glyceryl trinitrate):
- Acute angina
- Chest pain associated with ACS
Give examples of Long-acting Nitrates and its indication?
Long acting nitrates (e.g. isosobide mononitrate, ISMN) are used as 2nd line for prophylaxis of angina
- Where a BB and/or a CCB are insufficient or not tolerated
What is IV nitrates indicated in?
- treatment of pulmonary oedema (in conjunction with furosemide and O2)
What is the MOA of Nitrates?
Converted to NO:
- Increases cGMP synthesis
- Reduces intracellular Ca in vascular SMCs SMCs relax
venous, and to a lesser extent, arterial vasodilatation relaxation of the venous capacitance vessels reduces cardiac preload and LV filling reduces cardiac work and myocardial O2 demand relieves angina and cardiac failure
- Can relieve coronary vasospasm and dilate collateral vessels improves coronary perfusion
- Relax systemic arteries reduces peripheral resistance and afterload
- Most of the antianginal effects are mediated by reduction in preload
what are the main side effects of nitrates?
Due to the vasodilation:
- Flushing
- headaches
- light-headedness
- Hypotension
when taken regularly, there is the risk of tolerance (tachyphyalxis)
What is Nitrates contraindicated in?
- aortic stenosis
- haemodynamic instability (hypotension)
What other drugs does Nitrates interact with?
Must NOT be used with phosphodiesterase (PDE) inhibitors (e.g. Sildenafil)
- These enhance and prolong the hypotensive effects of nitrates
Use with caution in pts taking antihypertensive medications, in whom they may precipitate hypotension
Give an example of MRA and what does it stand for?
Mineralocorticoid Receptor Antagonists.
Spironolactone
What are the main indications of Spironolactone?
1st line diuretic for:
- Ascites
- Oedema due to liver cirrhosis
- CHF: of at least moderate severity or arising within 1 month of a MI, usually as an addition to a beta blocker and an ACEi/ARB
^if showing signs of fluid overload e.g. peripheral oedema, weight gain - Primary hyperaldosteronism for pts awaiting surgery or for whom surgery is not an option
- 4th line for hypertension??
What is the MOA of Spironolactone?
Competitively bind to the aldosterone receptor which prevents the binding of aldosterone (produced by adrenal cortex) to the MR in distal tubules of the kidney.
This decreases the activity of the luminal epithelial Na+ channels (ENaC) to decrease BP, and increase Na and water excretion, and K retention
Effect is greatest when circulating aldosterone is increased, e.g. in:
- Primary hyperaldosteronism
- Cirrhosis