Flashcards in Cardiac Deck (47):
Name the 5 main types of hypertensives
Angiotensin converting enzyme inhibitor (ACEi)
Angiotensin II Receptor Blocker (ARB)
Beta adrenoreceptor blockers (B Blocker)
Ca channel blocker (CCB)
What are the effects of ACEi
Reduces aldosterone (increased Na+, H20 secretion)
Side effects of ACEi
Persistent dry cough
NSAIDs used in conjunction with ACEi increase RF risk
Stop medication if patient is in renal failure, has an AKI or renal artery stenosis
Examples of ACEi
Ramipril. Max 10mg, initial 2.5mg OD
Lisinopril: Max 80mg, initial 2.5
Perindopril: Max 10mg. Initial 5mg
What is the mode of action of ACEi
Bind to angiotensin converting enzymes on the surface of pulmonary endothelium and renal endothelium preventing conversion of Angiotensin I to Angiotensin II. Thereby causing vasodilation, reduced BP and reduced aldosterone
Mechanism of action for B blockers
Blocks B1 adrenergic receptors:
In SAN has negative chronotrophic effect
In myocardium has negative ionotrophic effects (decreases force of contraction)
Side effects of B Blocker
Examples of B Blockers
Atenolol: 25-50mg daily
Propanolol: 40mg OD to TD
Metoprolol: IVI max 15mg oral 50-200 mg (CS)
Bisoprolol: 10mg daily max. Long term (CS)
CS= Cardio selective
Mode of action for ARBs
Binds to angiotensin receptors preventing the binding of angiotensin II resulting in: reduced after load and inhibition of vasoconstriction
Cautions and side effects of ARB
1. Do not use in patient in AKI or renal artery stenosis
2. Do not use in patient with K+ sparring diuretics or IV K+ as on of the SE is hyperkalemia
3. Do not use in conjunction with NSAID = Increased risk of RF.
4. Avoid use with diuretics
Must monitor K+, BP and renal function
Examples of ARBs
Losartan max. 100mg daily. initial 50 mg
Candesartan max. 32 mg daily, initial 4.8 mg
Reduce dose in renal/hepatic patients
Three main classes of CCBs
Phenilalkylamines (e.g. Verapamil)
Benzothiazipines (e.g. diltiazem)
Dihydropyridines (e.g. Amlodipine)
Name 5 CCBs
Major side effects of CCBs
Ankle swelling/peripheral oedema
Avoid use if: Poor LV function, aortic stenosis, Heart block,unstable angina, grapefruit juice
Major side effects of verapamil and diltiazem
What is the mode of action of aspirin
Aspirin is an anti-platelet. It is a non selective COX inhibitor.
Normally arachidonic acid is converted to thromboxane, prostaglandin and prostacyclin. Therefore inhibiting conversion prevents platelet aggregation, inflammation and pain relief. Its main effect is preventing platelet aggregation
What are the indications for aspirin
Prophylaxis for ACS, Angina, MI, Stroke, PVD, AF, analgesia, rheumatoid arthritis
What are the contra indications for aspirin
High risk of bleeding
<16 yrs old (reyes syndrome)
What are the doses for aspirin?
Loading dose 300 mg
Regular dose 75 mg
For pain: max 4g daily
Class and mode of action of digoxin
Na-K pump inhibitor so decreases contraction force (negative ionotrophic)
Acts on AVN (decrease conduction, negative chronotrophic)
Bradycardia leading to arrhythmia
Caution when patient is in renal failure, electrolyte imbalance.
Diuretics further decrease K+
ACEi, NSAIDs, Amiodarone, CCBs all enhance digoxin effects
What is the contraindication for digoxin
2nd degree HB, complete HB, risk of ventricular arrhythmias
Loading + maintenance dose of digoxin
62.5 then 500 mg daily
What are the indications for amiodarone?
Treatment of arrhythmias, particularly when other drugs are ineffective or contra-indicated (including paroxysmal supraventricular, nodal and ventricular tachycardias, atrial fibrillation and flutter, ventricular fibrillation, and tachyarrhythmias associated with WPW
What is the mode of action of amiodarone?
Inhibits voltage gated Ca, K+ thereby prolonging the refractory period, hence slowing the heart rate.
Also acts on B1 adrenergic receptors as an antagonist reducing the heart rate.
It is primarily a class III arrhythmic drug
What are the different classes of arrhythmic drugs?
Class I agents interfere with the sodium (Na+) channel.
Class II agents are anti-sympathetic nervous system agents. Most agents in this class are beta blockers.
Class III agents affect potassium (K+) efflux.
Class IV agents affect calcium channels and the AV node.
Class V agents work by other or unknown mechanisms.
Name the side effects of amiodarone?
Photo sensitivity (most common complaint)
Grey discolouration to the skin
Name the contraindications for amiodarone?
Active thyroid disease
Severe conduction disturbances (heart block, bradycardia)
Drugs that prolong the QT interval (digoxin, diltiazem, Verapamil)
Which drugs prolong the QT interval
Antipsychotics (e.g. haloperidol)
Type 1a antiarrythmics (e.g. Quinidine)
Type IC antiarrhythmics (e.g. Flecainide)
Class III antiarrhythmics (e.g. Sotalol, amiodarone)
Tricyclic antidepressants (e.g. Amitriptyline)
Antihistamines (e.g. Diphenhydramine)
Dosages for amiodarone
Oral: 200 mg TDS (1st week), 200mg OD (week 2) then ween down to 200mg OD.
IV: initially 5 mg/kg, to be given over 20–120 minutes with ECG monitoring, subsequent infusions given if necessary according to response; maximum 1.2 g per day.
V fib: Initially 300 mg, dose to be considered after administration of adrenaline, dose should be given from a pre-filled syringe or diluted in 20 mL Glucose 5%, then (by intravenous injection) 150 mg if required, followed by (by intravenous infusion) 900 mg/24 hours.
Indications for ivabradine
Treatment of angina in patients with normal sinus rhythm
Mild to severe chronic heart failure
Usually used when patient is on their maximum dosage of B blocker
Mechanism of action
Ivabradine lowers heart rate by selectively inhibiting If channels ("funny channels") in the heart in a concentration-dependent manner without affecting any other cardiac ionic channels (including calcium or potassium).
The If currents are located in the sinoatrial node and are the home of all cardiac pacemaker activity. Ivabradine therefore lowers the pacemaker firing rate, consequently lowering heart rate and reducing myocardial oxygen demand.
Side effects of ivabradine (5)
first-degree heart block;
What are the 5 main classes of diuretics
Potassium sparing diuretic
Name some loop diuretics and the general site of action
Furosemide (40mg morning. max 80mg daily)
What is the mode of action for loop diuretics
Acts at the thick ascending limb of henle inhibiting Nak-K pump so no reabsorption of Na and therefore fluid excretion
Side effects of loop diuretics
Hearing loss, tinnitus
Contraindication for loop diuretics
Severe hypokalemia or hyponatraemia
Renal failure due to nephrotoxic or hepatotoxic drugs
Management of moderate to severe PAD
pentoxifylline, cilostazol, or naftidrofuryl
Mode of action of pentoxifylline
Pentoxifylline inhibits erythrocyte phosphodiesterase, resulting in an increase in erythrocyte cAMP activity. Subsequently, the erythrocyte membrane becomes more resistant to deformity. Along with erythrocyte activity, pentoxifylline also decreases blood viscosity by reducing plasma fibrinogen concentrations and increasing fibrinolytic activity
Side effects of pentoxifylline
Rare: Angina, hypotension, bleeding
Contraindication of pentoxifylline
MIs, Arrythmias, Haemorrhages
Mode of action of cilostazol
yclic AMP (cAMP) phosphodiesterase III inhibitors (PDE III inhibitors), inhibiting phosphodiesterase activity and suppressing cAMP degradation with a resultant increase in cAMP in platelets and blood vessels, leading to inhibition of platelet aggregation and vasodilation
Side effect of cilostazol
Abdo pain, angina, diarrhoea, dizziness, headache, fatigue
Contraindication of cilostazol
Concurrent use with two ore more anticoagulants or antiplatelets
Mode of action of naftidrofuryl