Bane of my life Flashcards
What are the 3 broad categories of Anticoagulants?
- Heparins and Fondaparinux
- Oral warfarin – vitamin K antagonist,
- Newer direct oral anticoagulants (DOACs)
Name 3 DOACs
o dabigatran
o apixaban
o rivaroxaban
Mechanism of action: Unfractionated Heparin
- Enhances activity of antithrombin III (indirect IIa inhibitor)
- Antithrombin III inhibits thrombin.
- Heparins also inhibit multiple other factors of the coagulation cascade.
- This produces its anticoagulant effect.
Indications: Unfractionated Heparin
- Treatment and prophylaxis of thromboembolic diseases, including induction of vitamin K antagonists.
- Renal dialysis (haemodialysis)
- Acute Coronary Syndrome treatment
Mechanism of action: Warfarin
- Inhibits vitamin K epoxide reductase.
- Prevents recycling of vitamin K to reduced form after carboxylation of coagulation factors II, VII, IX and X.
- Prevents thrombus formation.
Indications: Warfarin
- Treatment of venous thromboembolism
* Thromboprophylaxis in: AF / metallic heart valves / cardiomyopathy
Mechanism of action: Dabigatran
- Direct thrombin inhibitor; prevents conversion of fibrinogen to fibrin.
- Factor IIa inhibitor
- This prevents thrombus formation.
Remember: daBIgatran inhibits factor II (“BI”)
Indication(s): Dabigatran
- Prophylaxis of venous thromboembolism (especially post-operative)
- Thromboprophylaxis in non-valvular AF
Name 2 Factor Xa Antagonists
1) Rivaroxaban
2) Apixaban
Remember: RivaroXAban and ApiXAban are factor “Xa” inhibitors because they “ban” it
Mechanism of action: Rivaroxaban
- Inhibits conversion of prothrombin to thrombin, reducing concentrations of thrombin in the blood.
- This inhibits the formation of fibrin clots.
Indication(s): Rivaroxaban
- Prophylaxis of venous thromboembolism (especially post-operative)
- Thromboprophylaxis in non-valvular AF
- Treatment of venous thromboembolism
Mechanism of action: Epixaban
- Inhibits conversion of prothrombin to thrombin, reducing concentrations of thrombin in the blood.
- This inhibits the formation of fibrin clots.
Indication(s): Epixaban
- Prophylaxis of venous thromboembolism following hip or knee replacement surgery.
- Thromboprophylaxis in non-valvular AF.
Mechanism of action: Aspirin (Acetylsalicylic acid)
- Irreversible inactivation of cyclooxygenase (COX) enzyme.
- This reduces production of platelet thromboxane (TXA2) and endothelial prostaglandin (PGI2)
- Reduced thromboxane production reduces platelet aggregation and thrombus formation
- Reduced prostaglandin synthesis decreases nociceptive sensitisation and inflammation.
Indication(s): aspirin
- Secondary prevention of thrombotic events
* Pain relief
Mechanism of action: Clopidogrel
- Irreversibly blocks the ADP-receptor on platelet cell membranes.
- Consequently inhibits formation of GPIIb/IIIa complex, required for platelet aggregation.
- Decreased thrombus formation.
Indication(s): Clopidogrel
Secondary prevention of thrombotic events
Clopidogrel is not given after PCI.
Mechanism of action: Ticagrelor
Prevents platelet activation and aggregation.
Ticagrelor is an antagonist of the P2Y₁₂ receptor.
Indication(s): Ticagrelor
Used in combination with aspirin for the prevention of atherothrombotic events in patients with acute coronary syndrome
prevents re-infarction post-MI, in addition to aspirin
Shown to improve outcome compared to clopidogrel in acute coronary syndrome. Clopidogrel is not given after PCI.
Ticagrelor, in combination with low-dose aspirin, is recommended for up to 12 months as a treatment option in adults with acute coronary syndromes
Contraindications: Ticagrelor
Active bleeding
history of intracranial haemorrhage
patients taking warfarin
patients weighing <60kg
Classes of fibrinolytic drugs
1) Kinases
I. Streptokinase
II. Urokinase
2) Tissue plasminogen activators (tPA)
III. Alteplase
IV. Tenecteplase
V. Reteplase
Mechanism of action: Tenecteplase/Alteplase
- Recombinant form of tissue plasminogen activator
- Catalyses conversion of plasminogen to plasmin
- Promotes fibrin clot lysis
Indication(s): Tenecteplase/Alteplase
- Acute ischaemic stroke within 4.5 hours of onset
- Myocardial infarction within 12 hours of onset
- Massive pulmonary embolism
Name 2 Cardioselective Beta-Blockers
- Bisoprolol
* Atenolol
Mechanism of action: Bisoprolol/Atenolol
- blocks beta-1 receptors in cardiac and renal tissue.
- Inhibits sympathetic stimulation of the heart and renal vasculature.
- Blockade of SAN reduces HR (negative chronotrope)
- blockade of receptors in the myocardium depresses cardiac contractility (negative inotrope)
- blockade of beta-1 adrenoceptors in renal tissue inhibits the release of renin
Indication(s): Bisoprolol/Atenolol
- Hypertension
- Angina
- Rate-control in atrial fibrillation
• Bisoprolol may be used as part of supportive therapy for mild / moderate heart failure
Name 2 Non-Cardioselective Beta-Blockers
- Propranolol
* Carvedilol
Mechanism of action: Propanolol
Non-cardioselective beta-1-adrenoceptor antagonist.
Inhibits sympathetic stimulation in the heart
Mechanism of action: Carvedilol
Non-selective beta-1, beta-2 and alpha-1-adrenergic receptor antagonistic effects.
Inhibits sympathetic stimulation in the heart and vascular smooth muscle.
Indication(s): Propanolol/Carvedilol
- Hypertension
- Angina
- Anxiety
- Migraine prophylaxis
- Post-MI prophylaxis
Carvedilol may be used as part of supportive therapy for mild / moderate heart failure
Contraindication(s): Propanolol/Carvedilol
diabetic patients – risk of deranged carbohydrate metabolism
Asthma and COPD – risk of bronchospasm
Do not combine Beta-Blockers with rate-limiting Ca2+-Channel-Blockers (Verapamil / Diltiazem) in anti-hypertensive therapy (risk of heart block)
Propanolol is lipid-soluble and is predominantly cleared by the liver. Avoid in liver impairment. Avoid abrupt withdrawal – risk of liver impairment.
Name 3 ACE Inhibitors
- Ramipril
- Enalapril
- Lisinopril
Mechanism of action: ACEi
- Inhibits conversion of Angiotensin I to Angiotensin II (a more potent systemic vasoconstrictor).
- This subsequently inhibits Aldosterone release from the adrenal cortex, depressing renal sodium and fluid retention, thereby decreasing blood volume.
Indication(s): ACEi
- Hypertension
- Heart Failure
- Nephropathy
- Prevention of Cardiovascular events in high risk patients
Name 2 Nitrates
- Isosorbide Mononitrate
* Glyceryl Trinitrate (GTN)
Mechanism of action: Nitrates
Converted to Nitric Oxide (NO), a potent vasodilator.
Cardioselective, acting predominantly on coronary blood vessels, enhancing flow of blood to ischaemic areas of the myocardium.
Reduces myocardial oxygen consumption by reducing cardiac preload and afterload.
Indication(s): Nitrates
- Treatment of Angina
* Severe hypertension (intravenous GTN is sometimes used in this setting)
Name 2 Rate-limiting Calcium Channel Blockers
- Verapamil
* Diltiazem
Mechanism of action: Verapamil/Diltiazem
Prevent cellular entry of Ca2+ by blocking L-type calcium channels.
Myocardial and Smooth muscle contractility depressed. Cardiac contractility will be reduced.
Dilate coronary blood vessels and reduce afterload.
Antidysrhythmic actions due to prolonged atrioventricular node conduction – depresses heart rate.
Indication(s): Verapamil/Diltiazem
- Supraventricular arrhythmias
- Treatment of angina
- Hypertension
Contraindication(s): Verapamil/Diltiazem
heart failure and left ventricular dysfunction due to potent negative inotropy.
Avoid in bradycardia and hypotension.
Do not use with beta-blockers.
Name 2 Non Rate-limiting Calcium Channel Blockers
- Amlodipine
* Nifedipine
Mechanism of action: Amlodipine
Prevents cellular entry of Ca2+ by blocking L-type calcium channels.
Myocardial and smooth muscle contractility depressed – mainly affects smooth muscle.
Dilates coronary blood vessels and reduce afterload
Does not lower heart rate (heart rate may increase)
Indication(s): Amlodipine
- Hypertension
* Treatment of Angina
Name 2 HMG CoA Reductase Inhibitors
- Simvastatin
* Atorvastatin
Mechanism of action: statins
Competitively inhibits HMG CoA Reductase; the rate-determining enzyme in the synthesis of cholesterol.
This causes an increase in LDL-receptor expression, on the surface of hepatocytes.
Increases hepatic uptake of cholesterol, reducing plasma cholesterol levels.
Reduces development of atherosclerotic plaques.
Indication(s): statins
Familial hypercholesterolaemia
Prevention of cardiovascular events in high-risk patients.
Mechanism of action: Digoxin
Inhibits the Na+/K+ pump, causing a buildup of Na+ intracellularly.
In an effort to remove Na+, more Ca2+ is brought into the cell by the action of Na+/Ca2+ exchangers.
The buildup of Ca2+ is responsible for the increased force of contraction and reduced rate of conduction through the AV node.
Indication(s): Digoxin
- Heart Failure
* Rate control in Atrial fibrillation
Name an Anti-Arrhythmic Drug
Amiodarone
Mechanism of action: Amiodarone
Amiodarone blocks cardiac K+ channels, prolonging repolarization of the cardiac action potential.
Restores regular sinus rhythm.
slows atrioventricular nodal conduction.
Indication(s): Amiodarone
Supraventricular / ventricular arrhythmias.
NB: can affect thyroid gland due to high iodine content
Name 4 penicillins
- Flucloxacillin
- Amoxicillin
- Benzylpenicillin
- Penicillin V
Mechanism of action: penicillins
Attaches to penicillin-binding-proteins on forming bacterial cell walls.
This inhibits the transpeptidase enzyme which cross-links the bacterial cell wall.
Failure to cross-link induces bacterial cell autolysis.
Indication(s): penicillins
Flucloxacillin provides Staphylococcus aureus cover, amoxicillin does not
Amoxicillin provides some amount of gram-negative cover in addition to gram-positive drugs
Flucloxacillin:
• Soft tissue infection
• Staphylococcal endocarditis
• Otitis externa
Amoxicillin:
• Non-severe community acquired pneumonia