Drugs

Question 1

Adrenaline Indications and doses

Answer 1

• Cardiac Arrest: 1 mg IV / IO every 3-5 min
• Second-line treatment for cardiogenic shock: 0.05–1 mcg kg-1 min-1
• Can be used for Bradycardia which has not responded to atropine, and external pacing is unavailable or unsuccessful
• Anaphylaxis: 0.3-0.5mg IM (0.5ml per 1:1000 vial) or 50-100mcg IV in severe cases

Question 2

What receptors does adrenaline stimulate?

Answer 2

Alpha and Beta receptors to produce peripheral vasoconstriction

This increases systemic vascular resistance (SVR) during CPR and improves both cerebral and coronary perfusion pressures.

Question 3

Why do you need to be careful to avoid using adrenaline in Myocardial Ischaemia

Answer 3

In the beating heart, the action of adrenaline on β1 receptors increases heart rate and force of contraction.

This increases myocardial oxygen consumption which may worsen ischaemia.

Adrenaline increases myocardial excitability and is therefore potentially arrhythmogenic, especially during myocardial ischaemia.

Question 4

Indications and Doses for Amiodarone

Answer 4

• Refractory VF/pulseless VT :
  
  • 300mg IV
• Control of haemodynamically stable VT, polymorphic VT, and broad-complex tachycardia of uncertain origin
• Paroxysmal SVT when adenosine, vagal manoeuvres, and AV nodal blockade are unsuccessful.
• To control rapid ventricular rate caused by accessory pathway conduction (WPW) in pre-excited atrial arrhythmias
  
  • 300 mg IV over 20-60 min followed by an infusion of 900mg over 24 h

Question 5

Why can amiodarone by arrthymogenic

Answer 5

Bc it prolongs the QTc

Question 6

main SE of amiodarone

Answer 6

Hypotension and bradycardia
These can be prevented by slowing the rate of infusion

• prolonged oral use: photosensitivity, thyroid & hepatic dysfunction, peripheral neuropathy & pulmonary inflammation/fibrosis.

Question 7

Why is it preferred to administer amiodarone into a central vein?

Answer 7

may cause thrombophlebitis;

a central vein is preferable otherwise use a large peripheral vein followed by a 20 ml flush.

Question 8

Consideration of amiodarone with Warfarin or digoxin?

Answer 8

The plasma levels of warfarin and digoxin are increased by amiodarone;

therefore their doses should be readjusted.

INR for warfarin and digoxin levels should be monitored.

Question 9

Indications and dose for Aspirin

Answer 9

• Acute Coronary Syndrome: 300mg to be chewed

Followed by 75mg OD

Question 10

Aspirins mechanism of action?

Answer 10

Antiplatelet activity (prevents platelet adhesions)

Question 11

Indications and doses for Atropine

Answer 11

Sinus, atrial or nodal bradycardia when patient is symptomatic: 0.6mg increments IV to a maximum of 3 mg

Question 12

Atropines mechanism of action

Answer 12

antagonises the NT acetylcholine at the muscarinic receptors. This blocks the vagal activity at the SA and AV node

Question 13

Side effects of atropine?

Answer 13

blurred vision, dry mouth and urinary retention

Question 14

Indications and dose for Adenosine?

Answer 14

• Stable narrow-complex tachycardia (or broad-complex tachycardia: 6 mg, 12 mg, IV
• known to be a supraventricular tachycardia (SVT) with bundle branch block) which is not responding to vagal manoeuvres.

Question 15

How must Adenosine be administered

Answer 15

In a monitored environment as it can briefly cause ventricular asystole

Question 16

How can adenosine be used as a diagnostic tool?

Answer 16

it can be given to a patient with a broad-complex tachycardia of uncertain aetiology.

The ventricular rate in SVT will be slowed

but ventricular tachycardia (VT) is unchanged.

Question 17

Side effects of adenosine

Answer 17

nausea, flushing, and chest discomfort, sense of impending doom

Question 18

Adenosine is contraindicated in what cardiac arrhythmia?

Answer 18

in patients with WPW syndrome, as the conduction blockade through the AV node by adenosine may promote conduction down the accessory pathway. In the presence of pre-excited atrial fibrillation or flutter, this may cause a dangerously rapid ventricular response.

Question 19

Indications and dose examples for B-adrenergic drugs (B-blockers)

Answer 19

Narrow-complex tachycardias uncontrolled by vagal manoeuvres and/or adenosine in the patient with preserved ventricular function.

To control rate in AF and atrial flutter with < 48h duration and preserved ventricular function.

Atenolol (β1) 5 mg IV over 5 min

Question 20

Side effects of b-blockade

Answer 20

bradycardia, AV conduction delay, hypotension and bronchospasm

Question 21

B-blockers are contraindicated in?

Answer 21

Contraindicated in second- or third-degree heart block, hypotensive states, CHF and asthma.

Question 22

Indications and dose examples of Calcium channel blockers in an acute setting

Answer 22

• Stable narrow complex tachycardia that is not terminated by vagal manoeuvres or adenosine
• Control of ventricular rate in patients with AF or atrial flutter (< 48h)

ONLY USE IF SVT IS CONFIRMED (v negative inotropic effect)

Verapamil 2.5–5mg IV over 2 min or

Diltiazem 15-20 mg IV over 2 min

Question 23

How do CCB work?

Answer 23

calcium channel blocking drugs that slow conduction and increase the refractory period in the AV node.

These actions may terminate re-entry arrhythmias that involve the AV node (e.g. SVT) and contribute to control of ventricular response rate in patients with other atrial tachycardias.

Question 24

Indications and dose of dopamine in the acute setting?

Answer 24

Hypotension in the absence of hypovolemia

1-10 mcg kg-1 min-1

Question 25

How does dopamine work and how should it be administerd

Answer 25

Administered via a central vein infusion

It is the precursor of the naturally-occurring catecholamines adrenaline and noradrenaline.

It has a dose-dependent positive inotropic effect that is mediated by dopamine (D1 and D2), α1- and β1- receptors.

Question 26

Indications and dose of Dobutamine

Answer 26

Hypotension not caused by hypovolemia

Cardiogenic shock

5-20 mcg kg-1 min-1

Question 27

Indication and dose for magnesium in the acute setting

Answer 27

Shock refractory ventricular fibrillation in the presence of hypomagnesaemia: 2 g bolus IV

Ventricular tachyarrhythmias in the presence of hypomagnesaemia

Torsade de pointes: 2 g over 10min IV

Question 28

How to administer Nitroglycerin (+ dose)

Answer 28

Up to 3 sublingual or spray doses may be given at 5-minute intervals

IV initiated for specific indications: 12.5 to 25μg bolus, 10 to 20 μg/min infusion, titrated

Question 29

Nitro glycerin indications for a STEMI

Answer 29

First 24 to 48 hours in patients with STEMI and one or more of the following:

• Recurrent ischaemic chest pain
• LV failure (acute pulmonary oedema or CHF)
• Elevated BP (especially with signs of LV failure)
• Large anterior infarction
• Persistent ischaemia

Question 30

Precautions/contraindications with Nitroglycerin

Answer 30

• Contraindicated in hypotension
• Contraindicated in RV infarction
• Suspected RV infarction with inferior ST changes
• Limit BP drop to 10% if patient is normotensive
• Limit BP drop to 30% if patient is hypertensive
• Watch for a headache, drop in BP, syncope, tachycardia
• Tell patient to sit or lie down during administration

Question 31

indication for Tenecteplase (Metalyse)

Answer 31

acute mycardial infarction

Question 32

How does tenecteplase work?

Answer 32

recombinant fibrin-specific plasminogen activator that is derived from native tissue plasminogen activator (t-PA)

it breaks down clots

Question 33

Tenecteplase

• Half-Life:
• Onset:
• Metabolism:
• Metabolites:
  *

Answer 33

Half-Life: 90-130 min

Onset: 30 min

Metabolism: Liver

Metabolites: Degradation products (constituent amino acids of tenecteplase)

Excretion: Clearance: Plasma: 99-119 mL/min

Question 34

Dose of tenecteplase and how fast do you administer?

Answer 34

Single bolus tenecteplase features a simple, 5-tiered weight-based dosing schedule — tailored to the patient. The recommended total dose should not exceed 50 mg.

ADMINISTER as an IV BOLUS over 5 seconds. Tenecteplase is for IV administration only.