Cardiovascular Pharmacology Flashcards
What are ACE inhibitors primarily used for?
First-line treatment for hypertension in younger patients and treatment of heart failure
ACE inhibitors are also used for diabetic nephropathy and secondary prevention of ischaemic heart disease.
What is the mechanism of action of ACE inhibitors?
Inhibits conversion of angiotensin I to angiotensin II, leading to vasodilation and reduced blood pressure
This also decreases aldosterone release, reducing sodium and water retention.
What are the common side effects of ACE inhibitors?
- Cough
- Angioedema
- Hyperkalaemia
- First-dose hypotension
Cough occurs in about 15% of patients and may develop up to a year after starting treatment.
What should be monitored in patients taking ACE inhibitors?
Urea and electrolytes, especially creatinine and potassium levels
Acceptable changes include a creatinine increase of up to 30% and potassium up to 5.5 mmol/L.
Which patients should avoid ACE inhibitors?
- Pregnant or breastfeeding women
- Patients with renovascular disease
- Patients with aortic stenosis
- Patients with hereditary angioedema
Specialist advice is needed for patients with high potassium levels.
What is adenosine primarily used for?
Termination of supraventricular tachycardias
Its effects are enhanced by dipyridamole and blocked by theophyllines.
What is the mechanism of action of adenosine?
Causes transient heart block in the AV node by increasing outward potassium flux
It acts as an agonist of the A1 receptor.
What are common examples of ADP receptor inhibitors?
- Clopidogrel
- Prasugrel
- Ticagrelor
- Ticlopidine
These agents inhibit platelet activation mediated by ADP.
What is the recommended dual antiplatelet treatment for ACS according to NICE guidelines?
Aspirin (75mg daily) and Ticagrelor (90mg twice daily) for 12 months
Alternatively, aspirin with either prasugrel or clopidogrel can be used.
What are the notable adverse effects of ticagrelor?
Dyspnoea
This is due to impaired clearance of adenosine.
What is amiodarone primarily used for?
Treatment of atrial, nodal, and ventricular tachycardias
It is a class III antiarrhythmic agent.
What are the side effects of amiodarone?
- Thyroid dysfunction
- Corneal deposits
- Pulmonary fibrosis
- Liver fibrosis
- Peripheral neuropathy
- Photosensitivity
- Bradycardia
- Slate-grey appearance
Adverse effects can be long-term and require monitoring.
What is the mechanism of action of angiotensin II receptor blockers?
Block effects of angiotensin II at the AT1 receptor
They are used when patients do not tolerate ACE inhibitors.
What are examples of angiotensin II receptor blockers?
- Candesartan
- Losartan
- Irbesartan
These are used with caution in patients with renovascular disease.
What is atropine primarily used for?
Symptomatic bradycardia and treatment of organophosphate poisoning
IV atropine is the first-line treatment for bradycardia with adverse signs.
What are the physiological effects of atropine?
- Tachycardia
- Mydriasis
Atropine may trigger acute angle-closure glaucoma in susceptible patients.
What are the indications for beta-blockers?
- Angina
- Post-myocardial infarction
- Heart failure
- Arrhythmias
- Hypertension
- Thyrotoxicosis
- Migraine prophylaxis
- Anxiety
Beta-blockers improve symptoms and mortality in heart failure.
What are common side effects of beta-blockers?
- Bronchospasm
- Cold peripheries
- Fatigue
- Sleep disturbances
- Erectile dysfunction
These effects can impact patient compliance.
What is bivalirudin used for?
As an anticoagulant in the management of acute coronary syndrome
It is a reversible direct thrombin inhibitor.
What is the mechanism of action of dabigatran?
Direct thrombin inhibitor
It is an oral anticoagulant that does not require regular monitoring.
What are the contraindications for dabigatran?
Use is contraindicated in patients with prosthetic heart valves
This was advised after the RE-ALIGN study showed increased bleeding and thrombotic events.
What is the mechanism of action of dipyridamole?
Inhibits phosphodiesterase, elevating platelet cAMP levels
This reduces intracellular calcium levels and has additional actions on adenosine uptake.
What are examples of glycoprotein IIb/IIIa receptor antagonists?
- Abciximab
- Eptifibatide
- Tirofiban
These agents are used in acute coronary syndrome management.
What is the mechanism of action of hydralazine?
Increases cGMP, leading to smooth muscle relaxation
It is less commonly used today but may be used in hypertension during pregnancy.
What are the adverse effects of hydralazine?
- Tachycardia
- Flushing
- Fluid retention
- Headache
- Drug-induced lupus
These side effects can limit its use.
What is ivabradine used for?
Reducing heart rate in angina treatment
It acts on the If ion current in the sinoatrial node.
What are common adverse effects of ivabradine?
- Visual effects
- Headache
- Bradycardia
- Heart block
Visual effects include luminous phenomena.
What is Ivabradine and its primary mechanism of action?
Ivabradine is a class of anti-anginal drug that works by reducing the heart rate by acting on the If (‘funny’) ion current in the sinoatrial node.
What are common adverse effects of Ivabradine?
- visual effects (luminous phenomena)
- headache
- bradycardia
- heart block
What is the mechanism of action for loop diuretics?
Loop diuretics inhibit the Na-K-Cl cotransporter (NKCC) in the thick ascending limb of the loop of Henle, reducing NaCl absorption.
What are the indications for loop diuretics?
- heart failure (acute and chronic)
- resistant hypertension, particularly in patients with renal impairment
List some adverse effects of loop diuretics.
- hypotension
- hyponatraemia
- hypokalaemia
- hypomagnesaemia
- hypochloraemic alkalosis
- ototoxicity
- hypocalcaemia
- renal impairment
- hyperglycaemia
- gout
What was Minoxidil originally developed for?
Minoxidil was initially developed as an antihypertensive.
What is the primary use of Minoxidil today?
Minoxidil is now mainly used in the treatment of androgenic alopecia.
What is the mechanism of action of Nicorandil?
Nicorandil is a potassium-channel activator that causes vasodilation through activation of guanylyl cyclase, leading to increased cGMP.
What are common adverse effects of Nicorandil?
- headache
- flushing
- skin, mucosal and eye ulceration
- gastrointestinal ulcers including anal ulceration
What is the primary indication for Nitrates?
Nitrates are primarily indicated for the management of angina and the acute treatment of heart failure.
What is the mechanism of action of Nitrates?
Nitrates cause the release of nitric oxide in smooth muscle, activating guanylate cyclase, which converts GTP to cGMP, leading to reduced intracellular calcium levels.
What are common side effects of Nitrates?
- hypotension
- tachycardia
- headaches
- flushing
What is a major concern with nitrate tolerance?
Many patients develop tolerance to nitrates, reducing efficacy. The BNF advises adjusting dosing schedules to maintain effectiveness.
What enzyme do Statins inhibit?
Statins inhibit the action of HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis.
List some adverse effects of Statins.
- myopathy (myalgia, myositis, rhabdomyolysis)
- liver impairment
- increased risk of intracerebral haemorrhage
Who should receive a Statin?
- individuals with established cardiovascular disease
- those with a 10-year cardiovascular risk >= 10%
- patients with type 2 diabetes mellitus
- patients with type 1 diabetes diagnosed over 10 years ago or aged over 40
What is the mechanism of action of Thiazide diuretics?
Thiazide diuretics inhibit sodium reabsorption at the beginning of the distal convoluted tubule by blocking the thiazide-sensitive Na+-Clˆ’ symporter.
What are common adverse effects of Thiazide diuretics?
- dehydration
- postural hypotension
- hypokalaemia
- hyponatraemia
- hypercalcaemia
- gout
- impaired glucose tolerance
What is the mechanism of action of Warfarin?
Warfarin inhibits epoxide reductase, preventing the reduction of vitamin K to its active form, affecting clotting factors II, VII, IX, and X.
What are the indications for Warfarin?
- mechanical heart valves
- venous thromboembolism
- atrial fibrillation
What factors may potentiate the effect of Warfarin?
- liver disease
- P450 enzyme inhibitors (e.g., amiodarone, ciprofloxacin)
- cranberry juice
- NSAIDs
List some side effects of Warfarin.
- haemorrhage
- teratogenic effects
- skin necrosis
- purple toes
