Drugs Flashcards
What is an example of an alpha blocker?
Doxazosin, prazosin
How do alpha blockers work?
Blocking the alpha channel results in decreased TPR and MABP
What are alpha blockers used for?
Hypertension
What is the side effect of alpha blockers?
Postural hypotension
What is an example of an ACE inhibitor?
Lisinopril
How do ACE inhibitors work?
Block conversion of angiotensin 1 to angiotensin 2
What are ACE inhibitors used for?
Hypertension and heart failure
What are the side effects of ACE inhibitors?
Dry cough, renal failure and hypotension (especially with diuretics)
What is an example of an ARB?
Losartan
How do ARBs work?
Block the AT1 receptor for AT2
When are ARBs used?
When the dry cough of ACE inhibitors cannot be tolerated
What is the side effect of ARBs?
Renal failure
Why should ACE inhibitors and ARBs not be used in pregnancy?
Risk of renal artery stenosis
What is the general class of drug of alpha blockers, ACE inhibitors and ARBs?
Vasodilators
What is an example of a thiazide diuretic?
Bendroflumethiazide
How do thiazide diuretics work?
Block NaCl reabsorption in the distal tubule by blocking the NaCl co-transporter
What are thiazide diuretics used for?
Hypertension
What are side effects of diuretics?
Hypokalaemia (tiredness), hypoglycaemia (diabetes), increased uric acid (gout), arrhythmias
What is an example of a loop diuretic?
Furosemide
How do loop diuretics work?
Block NaCl reabsorption in the thick ascending loop of Henle by blocking the NaClK co-transporter
What are loop diuretics used for?
Hypertension, heart failure, oedema
What is an example of a dihydropyridine Ca++ antagonist?
Amlodipine
How do Ca++ antagonists work?
The L type Ca++ channels in vascular smooth muscle normally increase FoC, so blocking these means decreased TPR and MABP.
There is also coronary vasodilation
What are Ca++ antagonists used for?
Hypertension, angina and supraventricular arrhythmias
What are side effects of Ca++ antagonists?
Oedema, dizziness and hypotension
What are examples of rate limiting Ca++ antagonists?
Verapamil, diltiazem
When should you avoid use of rate limiting Ca++ antagonists?
With beta blockers
What is an example of a cardio selective beta blocker?
Atenolol
How do cardio selective beta blockers work?
Block beta 1 so stimulate Gs, increase cAMP and contractibility
When should beta blockers be used?
Heart failure, hypertension, angina
What is an example of a non-selective beta blocker?
Propranolol
When should a non-selective beta blocker be used?
Thyrotoxicosis
What do cardio non-selective beta blockers so the selective ones don’t?
Block beta 2 which causes coronary vasodilation and increases HR
What are side effects of beta blockers?
Cold peripheries, heart failure worsened if long term, bradycardia and tiredness
When should beta blockers not be used?
Asthma (can do selective) and intermittent claudication
What do Ca++ antagonists do to myocardial O2 requirement?
Decrease it
Which beta blocker is used in angina?
Atenolol
What does atenolol do to the oxygenation of the myocardium?
Increases it
What is a short acting nitrate?
GTN
What do small doses of nitrates cause?
Decreased preload and SV
What do large doses of nitrates cause?
Decreased MABP and afterload
What extra effect do nitrates have on the myocardium?
Increase perfusion to the ischaemic zone
What are side effects of nitrates?
Tolerance, headache, postural hypotension
What is an example of a long acting nitrate?
Isosorbide mononitrate
What is important about the metabolism of isosorbide mononitrate?
Resistant to first pass metabolism
What is an example of a sodium channel blocker?
Ranolozine
What do sodium blockers do?
Inhibit sodium current which decreases intracellular Ca++. This leads to reduced tension and oxygen requirements for the myocardium
When are sodium blockers used?
Chronic angina
What are side effects of sodium blockers (ranolozine)?
Constipation and dizziness
What is an example of a potassium channel opener?
Nicorandril
How do potassium channel openers work?
Promotes K+ efflux causing hyperpolarisation and smooth muscle relaxation/coronary vasodilation
When are potassium channel openers (nicorandril) used?
Stable angina not controlled by nitrates
What are side effects of potassium channel openers (nicorandril)?
Low BP and hypovolaemia, palpitations, weakness
What is another anti-anginal drug which doesn’t have a specific class?
Ivabradine
How does ivabradine work?
Prolongs diastolic time, decreases HR, increases SV, preserving BP
When is ivabradine used?
Chronic heart failure or angina
What are side effects of ivabradine?
Oedema, prolonged AV block
What are the three groups of anti-thrombotic drugs?
Anti-platelets, anti-coagulants, fibrinolytics
What are examples of anti-platelet drugs?
Aspirin, clopidogrel, ticagrelor, prasugrel
What do anti-platelet drugs do?
Prevent new thrombosis
When are anti-platelet drugs used?
Angina, acute MI, stroke, transient ischaemic attack
What are side effects of anti-platelet drugs?
Haemorrhage
When should you try to avoid use of anti-platelets?
Asthma and peptic ulcers
What are examples of anti-coagulants?
Warfarin, heparin, dabigatran, rivaroxiban
What is the only way warfarin can be taken?
Orally
What does warfarin do?
Prevents new thrombosis by blocking clotting factors 2, 7, 9, 10
When should anti-coagulants be used?
DVT, PE, NSTEMI, AF
What is the side effect of anti-coagulants?
Haemorrhage
How does rivaroxaban work?
Factor Xa inhibitor
How does dabigatran work?
Factor IIa inhibitor
What is a fibrinolytic drug?
Streptokinase
What do fibrinolytics do?
Dissolve formed clots
When are fibrinolytics used?
Primarily STEMI, rarely PE and stroke
When should you avoid using fibrinolytics?
Recent trauma or haemorrhage, bleeding tendancies
What are examples of anti-cholesterol drugs?
Statins, fibrates, bile acid binding resins and ezetimibe
What are examples of statins?
Simvastatin and atorvastatin
How do statins work?
Block enzyme HMG CoA reductase which reduces LDL production in the liver, also decreases inflammation and stabilises atherosclerotic plaques
When should statins be used?
Hypercholesterolaemia, diabetes, angina/MI/stroke/TIA
What are side effects of statins?
Myopathy, renal failure, aches
Why should statins not be given in pregnancy?
Cholesterol needed for foetus development
When are statins ineffective?
Familial hypercholesterolaemia
What is an example of a fibrate?
Bezafibrate
How do fibrates work?
mainly by decreasing triglyceride levels and a slight decrease in LDL and HDL
When are fibrates used?
First line for hypertriglyceridaemia but also in low HDL
What is the side effect of fibrates and what is done to decrease this?
Myositis- use with statins
What are examples of bile acid binding resins?
Colestipol and colestyramine
How do bile acid binding resins work?
Excretion of bile salts so more cholesterol is converted to bile salts
What is a side effect of bile acid binding resins?
GI tract irritability
How does ezetimbe work?
Inhibits a protein transporter in duodenum enterocytes that reduces absorption of cholesterol
When is ezetimbe used?
In combination with statins when they are not effective enough alone
What are side effects of ezetimbe?
Diarrhoea, abdominal pain and headaches
What do all class I anti-arrhythmic drugs do?
Block sodium channels
What is a class IA anti-arrhythmic drug?
Disopyramide
What is the rate of dissociation of class IA anti-arrhythmics i.e. Disopyramide?
Moderate
What is a class IB anti-arrhythmic?
Lignocaine
What does lignocaine prevent?
Premature beats
What is lignocaine used for?
Ventricular tachycardias
What is the rate of dissociation of class IB anti-arrhythmic drugs i.e. lignocaine?
Fast (bypasses first pass metabolism)
What should lignocaine not be used with?
Beta blockers
When is Disopyramide used?
Life threatening arrhythmias
What is a class IC anti-arrhythmic drug?
Flecainide
What is the rate of dissociation of flecainide?
Slow
What effect does flecainide have on conduction?
Depresses it
What effect does flecainide have on the AP?
Slows conduction
When is flecainide contra-indicated?
Ventricular arrhythmias post MI
When should flecainide be used?
Atrial fibrillation or SVTs associated with an accessory pathway e.g. WPW
What are some side effects of all anti-arrhythmic drugs?
Phototoxicity, pulmonary fibrosis and thyroid abnormalities
What type of drugs are class II anti-arrhythmics?
Beta blockers
What is an example of a class II anti-arrhythmic?
Metaprolol
What do class to drugs i.e. metaprolol do?
Decrease rate of depolarisation in SA and AV nodes
What is an example of a class III anti-arrhythmic?
Amiodarone/Sotalol
What do class III anti-arrhythmics do?
Block potassium channels, prolong AP duration and increase refractory period
What are class III anti arrhythmics used for?
Atrial, nodal and ventricular tachycardias
What drug gives a slate grey appearance?
Amiodarone
What is an example of a class IV anti-arrhythmic drug?
Verapamil/Diltiazem
What do class IV anti-arrhythmic drugs e.g. verapamil do?
Block Ca++ channels and decrease force of contraction
What are examples of inotropic drugs?
Digoxin, Ca++ sensitisers and certain beta blockers
What does digoxin I do?
Blocks AV conduction to produce AV nodal delay
Blocks sarcolemma ATPase to increase contractility
When should digoxin be used?
AF and heart failure
What are side effects of digoxin?
Bradycardia and heart block, nausea, vomiting, ventricular arrhythmias
What is the bad side of digoxin?
Very narrow therapeutic index and so can produce ventricular arrhythmias
What is an example of a calcium sensitizer?
Levosimendan
How does levosimendan work?
Binds to troponin C in cardiac muscle sensitising it to the action of Ca++ and making it positively inotropic
What type of beta adrenoceptor agonists are inotropic?
Adrenaline and dobutamine
How must dobutamine be given?
IV
What do inotropic beta blockers increase?
Force, rate, CO and O2 ocnsumption
What do inotropic beta blockers decrease?
Cardiac efficiency
When should adrenaline be given and how?
IM in anaphylactic shock and IV in cardiac arrest
What side effect does adrenaline have?
Can cause arrhythmias
What does adrenaline block?
Beta 1 and 2 and alpha 1 receptors
What is dobutamine selective for?
Beta adrenoceptors
When is dobutamine used?
Acute heart failure
What is an unclassified non-selective muscarinic ACh receptor antagonist?
Atropine
What is atropine used for and how much should you give?
Severe bradycardia or ACh poisoning- always >600mg