ACC Cardiac/ arrythmia drugs

Question 1

Clinical indications for O2? x3

Answer 1

1. Hypoxaemia
2. PTX: To accelerate resorption of pleural gas
3. CO poisoning: to reduce half life of carboxyhaemoglobin

Question 2

O2 MOA?

Answer 2

Increases the PO2 in alveolar gas.
In PTX: it reduces the fraction of nitrogen in alveolar gas
In CO poisoning, it competes with CO to bind with hb and shortens half life of carboxyhaemoglobin

Question 3

O2 side effects/ warnings?

Answer 3

Lack of water vapour: dry throat
In T2RF/ COPD pts it results in high CO2 concentration causing resp acidosis, depressed consciousness and worsened tissue hypoxia

Question 4

O2 Doses?

Answer 4

Acute setting: 15L/ min via non-rebreathe mask (60-80%)
28% for T2RF patients
Nasal cannulae (24-50%) flow rate 1-4L/min)

Question 5

Nitrates clinical indication? X3

Answer 5

Short acting (GTN): Acute angina and ACS 
Long acting (Isosorbide mononitrate): angina prophylaxis where Bblockers and or CCB don't work 
IV nitrates: Pulmonary oedema- used in combo with furosemide and O2

Question 6

Nitrates MOA?

Nitrates elimination?

Answer 6

Nitrates are converted to NO
NO increases cGMP synthesis and reduces intracellular Ca2+ in SM cells= relaxation
This causes venous and a little arterial vasodilation
This reduces cardiac work and myocardial O2 demand relieving angina and cardiac failure

Eliminated by liver and partly passed unchanged in the urine

Question 7

SE of nitrates?

Answer 7

Headaches/ lightheadedness
Flushing
Hypotension
Sustained use= tolerance

Question 8

Cautions/ contraindications of Nitrates

Answer 8

CI: severe AS pts= cv collapse bc the heart can’t increase CO sufficiently to maintain pressure in dilated vasculature
CI: Pts with haemodynamic instability and HTN

Question 9

Nitrates interactions

Answer 9

Phosphodiesterase inhibitors e.g. sildenafil: enhance and prolong hypertensive effect of nitrates
Caution in pts already taking hypertensive medication= precipitate hypotension

Question 10

GTN and Isosorbide dose?

Answer 10

Spray GTN for angina prophylaxis: 400-800mg under tongue prn
Spray GTN for angina treatment: 400-800mg under tongue- 5 min intervals- after 3 seek medical attention
IV GTN= solution containing 50mg in 50ml= 1mg/ml

ISMN: angina prophylaxis and adjunct in CHF = 20mg BID-TID, increase if necessary to 120mg in divided daily dose

Question 11

How would you explain to the pt what the nitrates are for?

Answer 11

This medication is being prescribed to help you with your chest pain and or breathless.

You might develop a headache but this usually doesn’t last for long.

We normally advise patients to use GTN before an activity that might bring on your angina

As your BP can drop, it’s a good idea to sit down and rest for about 5 mins while taking them

Question 12

How do you monitor nitrate efficacy?

Answer 12

Do symptoms resolve

When using IV infusion measure blood pressure frequently

Question 13

Aspirin drug class and clinical indications x 3

Answer 13

Salicylates

ACS/ Acute Ischaemic stroke: rapid inhibition of platelet aggregation
Long term secondary prevention of thrombotic arterial events in patients with CV, cerebrovascular and PAD
To reduce risk of intracardiac thrombus and embolic stroke in AF

Question 14

Aspirin MOA?

Aspirin elimination?

Answer 14

Irreversibly inhibits COX to reduce production of arachidonic acid
This reduces platelets aggregation and the risk of arterial occlusion
Antiplatelet effects of aspirin occur at low doses and last for a lifetime

Elimination: Effects of aspirin last for the lifetime of the platelet, urinated out

Question 15

SE aspirin?

Answer 15

Gastrointestinal irritation
GI ulceration and haemorrhage
Hypersensitivity reactions= bronchospasm
Regular high-dose therapy will cause tinnitus
Life threatening in overdose: will cause hyperventilation, hearing changes, metabolic acidosis and confusion

Question 16

Aspirin contraindications/ caution?

Answer 16

Children <16 due to risk of reye’s syndrome
Pt’s with aspirin hypersensitivity
Should be avoided in the 3rd trimester of pregnancy where prostaglandin inhibition may lead to premature closure of the ductus arteriosus

Caution: people with peptic ulcers, provide gastric protection
Gout pts: can trigger an acute attack

Question 17

Aspirin interactions?

Answer 17

Interacts with other antiplatelet agents and increases risk of bleeding

Question 18

Aspirin dose and route?

Answer 18

ACS: Should be prescribed as a once only loading dose of 300mg followed by a regular dose of 75mg daily

Acute ischaemic stroke: 300mg QD for 2 weeks before switching to 75mg

Long term prevention of thrombosis: Useful after an acute event or in people with AF, 75mg QD

Pregnant women at mod-high risk of pre-eclampsia: 75–150 mg once daily from 12 weeks gestation until the birth of the baby.

Max daily dose of 4g: take with food to minimise gastric irritation

Question 19

What would you tell the pt when prescribing Aspirin?

Answer 19

Safety net: This drug aims to prevent heart attacks, stroke and to prolong life.
Watch out for indigestion of bleeding symptoms- seek medical advice if these occur

Question 20

Atropine clinical indications X 4/ drug class?

Answer 20

Muscarinic antagonist- emergency drug

Intraoperative bradycardia
Symptomatic bradycardia due to acute overdose of bblockers
Treatment of poisoning caused by organophosphorous insecticide/ nerve agent
GI disorder caused by SM spasms

Question 21

Atropine MOA?

Atropine metabolism/ elimination?

Answer 21

It binds to and inhibits muscarinic acetylcholine receptors producing a wide range of ACh effects- M1-M5 receptors

By the liver. 13-50% excreted unchanged in the liver

Question 22

Atropine SEs? x6

Answer 22

Constipation, urinary retention and anhidrosis (elderly)
Dizziness
Photophobia (eye)
Drowsiness
Dry mouth 
Flushing

Question 23

Atropine contraindications/ cautions?

Answer 23

Pts with: 
Acute closure glaucoma
GI obstruction
Paralytic ileus 
Pyloric stenosis
Severe UC

Caution: adults: acute MI, arrhythmias, autonomic neuropathy and elderly with polypharmacy: 2 or more antimuscarinics= toxicity

Question 24

Atropine interactions

Answer 24

add

Question 25

Atropine dose and route

Answer 25

add

Question 26

Indications for morphine (X4) and drug class

Answer 26

Rapid relief for acute severe pain e.g post op pain and MI Relief of chronic pain where other 2 rungs of ladder failed For relief of breathlessness in end of life care To relieve breathlessness and anxiety in acute pulmonary oedema (used with oxygen, nitrates and furosemide) It's an opioid analgesic

Question 27

Morphine MOA

Answer 27

Works mainly by binding to mu-opioid receptor: activation of descending inhibitory pathways of the CNS AND inhibition of the nociceptive afferent neurons of the PNS

Question 28

Morphine SEs

Answer 28

Constipation: Mu receptor activation increases SM tone and reduces motility N+V: from activated chemoreceptive trigger zone Drowsiness Respiratory depression: reduces respiratory drive Confusion Pupillary constriction: due to activation of Edinger-westphal nucleus Neurological depression in higher doses Itchy skin due to histamine release

Question 29

Morphine interactions

Answer 29

Should not be used with other sedating drugs: Antipsychotics Benzodiazepines TCAs

Question 30

Morphine contra-indications/ cautions x3

Answer 30

Morphine relies on liver and kidneys for elimination. Dose should be reduced in hepatic failure and renal impairment Morphine should not be given in resp failure unless for palliative purposes under senior guidance AVOID in biliary colic patients as it may cause spasm of the sphincter of oddi

Question 31

Morphine dose and route

Answer 31

Acute severe pain: IV 2-10mg- tailor to pain Chronic pain: Oral immediate release morphine: 5mg every 4 hours Breakthrough analgesia should be prescribed alongside regular treatment Immediate release should be 1/6 the total regular daily dose

Question 32

Ticagrelor drug class and indications?

Answer 32

p2y12 inhibitor/ antiplatelet drug Prevention of Atherothombotic events in patients with ACS or history of MI (used with aspirin)

Question 33

Ticagrelor MOA Ticagrelor elimination?

Answer 33

Prevents platelet activation and aggregation by inhibiting P2Y12 Receptor antagonist Eliminated by the liver

Question 34

Ticagrelor SEs?

Answer 34

``` Constipation/ diarrhoea/ dyspepsia Haemorrhage Headache/ dizziness Hyperuricaemia/ gout/ gouty arthritis Skin reactions ```

Question 35

Ticagrelor interactions

Answer 35

Interacts with many drugs and increases risk of bleeding (tyrosine kinase inhibitors/ anticoag meds) , bradycardia (beta blockers/ ccbs/ strong opioids) or ticagrelor toxicity

Question 36

Ticagrelor contraindications/ cautions

Answer 36

Contraindicated in patients with: active bleeding history of intracranial haemorrhage Use with cautions in patients with: Asthma, bradycadia, COPD (DISCONTINUE 5 days before surgery), history of hyperuricaemia and second or 3rd degree block

Question 37

Ticagrelor dose and route

Answer 37

ACS patients: Initially 180mg for 1 dose. Then twice daily 90mg for up to 12 months Patients with history of MI: 60mg twice daily

Question 38

What should be monitored in patients who have just started ticagelor?

Answer 38

Renal function- measured by U&Es

Question 39

Enoxaparin (Dalta, Tinz and Fondaparinux) drug class and clinical indications

Answer 39

LMWH VTE: LMWH- first choice drug for VTE prophylaxis in hospital inpatients. DVT and PE ACS: LMWH/ fonadaparinux are part of the first line therapy to improve revascularisation and prevent intracoronary thrombus progression

Question 40

Enoxaparin and co MOA? Elimination?

Answer 40

Generally heparins prevent the formation and propagation of blood clots Unfractionated heparin activates antithrombin> inactivates clotting factor XA and thrombin Enoxaparin preferentially inhibits factor XA Fondaparinux is a synthetic compound that is similar to heparin Elimination via kidneys half life 4.5 hours

Question 41

LMWHs SEs?

Answer 41

Bleeding Injection site reaction Heparin induced thrombocytopenia (rare)

Question 42

LMWH interactions?

Answer 42

Combining antithrombotic drugs increases risk of bleeding

Question 43

Regarding bleeding caused by heparin therapy what's the use of protamine?

Answer 43

Protamine can be given to reverse anticoagulation- this is only effective for unfractionated heparins

Question 44

LMWH contraindications and cautions?

Answer 44

Should be used in caution with patients at increased risk of bleeding including those with Clotting disorders , Severe uncontrolled hypertension, Recent surgery or trauma Heparins should be avoided around invasive procedures esp lumbar puncture and spinal anaesthesia Should be used with caution in patients with renal impairment: use lower dose or unfractionated heparin instead

Question 45

LMWH dose and route?

Answer 45

Usually given via subcut injection into abdominal wall. Don't use the arm as there's not enough flesh here Prophylaxis of VTE: 40MG sc QD or Dalteparin 5000UNITS SC daily VTE and ACS treatment: Unfractionated heparin may be given by IV infusion

Question 46

What should you monitor while patient is on treatment of LMWH

Answer 46

FBC and renal profile should be checked | In prolonged therapy monitor platelet count

Question 47

Adrenaline drug class and clinical indications? x3

Answer 47

It's a sympathomimetic agent: a vasoconstrictor Indications are 1. In cardiac arrest 2. Anaphylaxis 3. To induce local vasoconstriction e.g. in endoscopy to control mucosal bleeding

Question 48

Adrenaline MOA?

Answer 48

Potent agonist of the α1, α2, β1 and β2 adrenoceptors α1-mediated: vasoconstriction of skin, mucosa and abdominal vessels β1 mediated: increases chronotropy (HR), force of contraction (inotropy) and dromotropy (myocardial excitability) β2 mediated: Vasodilation of vessels supplying heart and muscles. Also causes bronchodilation and suppression of inflammatory mediator release from mast cells

Question 49

What do the following mean? Positive chronotropy Positive dromotropy Positive inotropy Positive lusitropy

Answer 49

Positive chronotropy (SA node) – increase heart rate Positive dromotropy – faster conduction in AV node Positive inotropy – stronger atrial and ventricular contractions Positive lusitropy – greater relaxation to allow more blood in

Question 50

Adrenaline onset time elimination?

Answer 50

3-5 mins. Excreted in the urine via the kidneys.

Question 51

Adrenaline SEs

Answer 51

Think high speed! Anxiety/ headache Tremor/ anxiety palpitations Can cause angina, MI and arrythmias esp in patients with existing heart disease

Question 52

Adrenaline cautions/ contraindications

Answer 52

Should be given with caution in patients with existing heart disease Combination adrenaline anaesthetic peps should not be used in areas supplied by an end artery (poor collateral supply)- vasoconstriction will cause necrosis

Question 53

Adrenaline interactions?

Answer 53

Adrenaline + Bblockers= widespread vasoconstriction

Question 54

Adrenaline dose and route?

Answer 54

CPR: 1 mg every 3–5 minutes as required, a 1 in 10 000 (100 micrograms/mL) solution is recommended Acute hypotension in child: Initially 100 nanograms/kg/minute, adjusted according to response Anaphylaxis adult: 500 micrograms, using adrenaline 1 in 1000 (1 mg/mL) injection, repeat dose after 5 minutes if no response Anaphylaxis child 6months-5yrs/ 6-11ys/ 12-17yrs: 150mcg / 300mcg/ 500mcg: for all use 1mg/ml injection

Question 55

Adenosine drug class and clinical indications?

Answer 55

Adenosine receptor agonist First line drug for supraventricular tachycardia (e.g. WPW)

Question 56

Adenosine MOA Adenosine elimination

Answer 56

Acts on the G-protein coupled receptors and produces the following actions: 1. Reduces frequency of spontaneous depolarisation which slows sinus rate and conduction velocity 2. This all increases AV node refractoriness Elimination: cleared from the plasma by cellular uptake

Question 57

Adenosine SEs

Answer 57

Bradycardia Asystole Breathlessness and sometime sense of impending doom

Question 58

Adenosine contraindications/ cautions?

Answer 58

Contraindicated in patients who won't tolerate transient Bradycardic effects e.g. patients with a. Hypotension b. coronary ischaemia c. decompensated heart failure Can induce bronchospasm, avoid in patients with a. Asthma b. Copd Use with caution in patients with recent myocardial infarction, heart transplant and bundle branch block

Question 59

Adenosine interactions

Answer 59

Dipyridamole blocks cellular uptake of adenosine- effects last for longer Theophylline, aminophylline and caffeine are competitive antagonists and reduce its effects

Question 60

Adenosine dose and route?

Answer 60

Initially 6 mg, administer into central or large peripheral vein and give over 2 seconds Cardiac monitoring required Followed by 12 mg after 1–2 minutes and another 12 mg after 1-2 mins if no response

Question 61

Amiodarone drug class and clinical indications?

Answer 61

Anti-arrhythmics AF, Atrial Flutter, SVT VT, Refractory VF and shock resistant VF

Question 62

Amiodarone MOA Amiodarone elimination

Answer 62

Effects are on myocardial cells Blockade of sodium, calcium and potassium channels Antagonism of alpha and B-adrenergic receptors: these effects reduce spontaneous depolarisation (automaticity), slow conduction velocity and increase resistance to depolarisation (refractoriness) By interfering with AV node conduction, amiodarone reduces the ventricular rate in AF and atrial flutter Elim: Hepatic metabolism and biliary excretion

Question 63

Amiodarone SEs

Answer 63

Can cause hypotension during IV infusion Lungs: Pneumonitis Heart: Bradycardia and AV block Liver: Hepatitis Skin: Photosensitivity and grey discolouration Thyroid abnormalities: due to it’s iodine content (amiodarone) : hypo and hyperthyroidism Compared to the other drugs it causes little myocardial depression

Question 64

Amiodarone contraindications and cautions

Answer 64

Severe HTN Heart block Active thyroid disease

Question 65

Amiodarone interactions

Answer 65

Increases the plasma concentration of - Digoxin - Diltiazem - Verapamil This may increase the risk of bradycardia, AV block and HF. Doses of the drugs should be halved if amiodarone is started

Question 66

Amiodarone dose and route

Answer 66

For arrhythmias, when nothing else works: 200 mg TID for 1 week, then reduced to 200 mg BID for a further week, followed by maintenance dose, usually 200 mg daily Initially 5 mg/kg, to be given over 20–120 minutes with ECG monitoring CPR: Initially 300 mg, dose to be given over at least 3 minutes

Question 67

Metoprolol drug class and clinical indications

Answer 67

Beta blocker Angina and HTN Prophylaxis for HF Arrhythmias Migraine prophylaxis

Question 68

Metoprolol MOA Elimination

Answer 68

Beta 1 adrenergic receptor inhibitor This decreases CO by producing negative chronotropic and inotropic effects Elim: Absorbed in GIT. Metabolised by CYP2D6 and to a lesser extent CYP3A4 Excreted by the kidneys

Question 69

Metoprolol SEs

Answer 69

As with all beta blockers: ``` Abdo discomfort Bradycardia Confusion Depression Diarrhoea Dizziness Dry eye ```

Question 70

Metoprolol contraindications and cautions

Answer 70

``` Portal HTN (risk of deterioration in liver function) Psoriasis ``` Caution in combo with diltiazem or verapamil: risk of heart block With bradycardia (<50bpm) In diabetic pts with hypos: risk of suppressing hypoglycaemic symptoms

Question 71

Metoprolol interactions

Answer 71

NSAIDS may reduce the ability of metoprolol to lower the patient’s blood pressure Catecholamine-depleting medications, such as guanethidine or reserpine, can have an additive effect when taken with beta-blocking agents like metoprolol.

Question 72

Metoprolol dose

Answer 72

HTN: 100mg QD (IR) 200mg (MR) Angina: 50-100mg (B-TID). 200-400mg (MR) FILL IN arrythmias and migraine prophylaxis bnf https://bnf.nice.org.uk/drug/metoprolol-tartrate.html#cautions