Cardiovascular and Respiratory Drugs Flashcards Preview

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Flashcards in Cardiovascular and Respiratory Drugs Deck (65)
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1
Q

What is heart failure?

A

The heart is unable to function effectively to pump around the body.

2
Q

What are the signs associated with left heart failure?

A
Pulmonary oedema
Increased RR
Lethargy
Dyspnoea
- Cough (dogs)
- Tachycardia
- Exercise intolerance
- Pale MMs/Slow CRT
3
Q

What is RAAS?

A

Renin Angiotensin Aldosterone System

4
Q

What are the signs associated with right sided heart failure?

A
- Pleural effusion
increased RR
Lethargy
Dyspnoea
- Tachycardia
- Exercise intolerance
- Pale MMs/Slow CRT
- Ascites
5
Q

What is Ascites?

A

Accumulation of fluid in the peritoneal cavity, causing abdomen swelling.

6
Q

What is compensation in the heart?

A

As heart fails and stroke volume decreases, heart will increase rate to maintain cardiac output.

7
Q

What happens to the heart chamber during this process?

A

Heart chamber dilation increases contractility (Starling’s Law).

8
Q

What is the Cardiac output calculations?

A

CO = Stroke Volume X Heart rate

9
Q

How would Blood Pressure be maintained?

A

As BP drops, RAAS is activated to increase BP and water retention.

10
Q

How is Angiotensin enzyme activated?

A

The Renin activates a cascade where angiotensin converting enzyme (ACE) is activated.

11
Q

What causes Angiotensin?

A
  • Blood vessel constriction

- Aldosterone Secretion

12
Q

When Aldosterone acts on the kidney, what happens?

A

This causes Na retention, water retention, to increased BP.

13
Q

How does the compensation mechanisms work when heart failure occurs?

A

Increased HR and SVR (Systemic Vascular Resistence) make the heart work harder -> Increased O2 demand and fatigue.
Increased fluid retention lead to pulmonary oedema, ascites etc.

14
Q

Why do we treat Heart failure?

A
Improve quality of life. 
- exercise intolerance
- Appetite
Slow progression of disease. 
- Reduce likelihood of sudden death
15
Q

How do we want to treat Acute CHF (cardiac heart failure) ?

A
Reduced hypoxaemia
Reduce effusions
- Diuretics
- Vasodilators
Improve cardiac output
- Positive ionotropes
Minimise stress.
16
Q

How do we want to treat Chronic CHF?

A
  • Reduce effusions/pre-load
  • Improve cardiac function
  • Prevent thromboembolism
  • Treat arrhythmia
  • Reduce cardiac re-modelling.
17
Q

What cardiovascular drug are there?

A
  • Diuretics
  • Vasodilators
  • Positive ionotropes
  • Anti-arrhythmic
  • Anti-thrombotics
18
Q

What do Diuretics do?

A

Removes excess body water by increasing urine flow and sodium excretion.

19
Q

Name 4 classes of Diuretics?

A
  • Loop diuretics
  • Thiazide diuretics
  • Potassium-sparing diuretics
  • Osmotic diuretics
20
Q

What is Vasodilators? and what do they do?

A

Relax smooth muscle of vessels. Lowers resistance to blood flow. -> reduced after load.

21
Q

Where do Loop diuretics act? What drugs? and possible side effects?

A

In the ascending limb in the kidney.
Furosemide medications.
Inhibits Na, Ca, Mg absorption.
Swapped Na with Potassium in distal convoluted tubule (K+ is urinated out).
Side effect - Hypokalaemia, hypovolaemia.

22
Q

Where does the Thiazide diuretics act? what drugs? and possible side effects?

A
Distal Convoluted tubule
- inhibits Na/Cl reabsorption. 
- Na+ is also swapped for K+. 
Side effects - Hypokalaemia
Hypochlorothiazide
23
Q

Where does the Osmotic diuretics act? What drugs? And possible side effects?

A

Proximal convoluted tubules + Loop of Henle.
Large molecules, encourage water in the tubules by osmosis.
Mannitol.
Not really used for HF, more short-term medicated.

24
Q

Where does the K-Sparing diuretics act?

A

Distal Convoluted Tubules + Collecting duct
antagonises Aldosterone
-> Na excreted, K retention.
increases the risk of hyperkalaemia.

25
Q

What drugs and side effects used for K Sparing diuretics?

A
  • Poor diuretics effect on its own, use in combination with the other diuretics.
    Reduces cardiac remodelling.
  • Spironlactone drugs.
26
Q

What are the three categories of vasodilators?

A
  • Arterial vasodilators (hydralazine)
  • Venodilators (Nitrogylcerin, nitrates)
  • Mixed arterial and venous (ACE inhibitors).
27
Q

What are Arterial Dilators?

A

Relax smooth muscle in arteries and arterioles.

28
Q

What drugs are used for vasodilators?

A
  • Nitrogylcerin
  • Absorbed through skin and mucosa
    Use in acute CHF with pulmonary oedema to reduce pre-load.
  • Clinical doses, overdose causes arteriodilation as well -> severe hypotension.
    Absorbed and administered in the ear.
    WEAR GLOVES.
29
Q

What does ACE inhibitors effects?

A
  • Venous and arterial dilation
  • Decreased Na and H20 retention.
  • Decrease in BP
30
Q

What ACE inhibitors drugs are used?

A

Benazepril

Enalapril

31
Q

What is a positive ionotropes?

A

Increases the contraction of the heart. May cause increased oxygen consumption and arrhythmia in a weakened heart.

32
Q

Name 3 positive ionotropes examples.

A
  • Catecholamines
  • Inodilators
  • Cardiac Glycosides
33
Q

What drug is a Catecholamines type?

A
  • Adrenaline
34
Q

What receptor does catecholamines act on?

A

Adrenoreceptors.

Beta 1 adrenoreceptors on the heart and increases HR (SA and AV nodes) and increased force of contraction.

35
Q

When is adrenaline used and the side effects?

A

Used for patients having cardiac arrest, anaphylaxis, emergency bronchodilation. Potential to cause severe arrhythmia.

36
Q

What is Dobutamine drug and side effects?

A

Improves cardiac contractility with less of a potential cause arrythmias

37
Q

What are Inodilators?

A

= Positive ionotrope and vasodilators.

Inhibits phosphodeisterace causing vasodilation and increased contractility.

38
Q

When do we not use Inodilators?

A

Calcium channel blockers.

39
Q

What is Cardiac glycosides and which drugs are used?

A

Inhibits Na/K ATP-ase pump altering electrolyte balance.
Increases Ca and Na therefore lowering resting potential -> increasing contractility
- Digoxin
(On an ECG - There is a dip before the T waves)
As it is mixing with the Na and Ca levels

40
Q

What negative effect does the Cardiac gylcosides?

A

Stimulates the vagus nerve centrally. Slows the depolarisation of SA node and conduction at AV node.
- Controls HR in arterial fibrillation and sinus tachycardia.

41
Q

What drugs are used for Tachyarrythmias?

A
  • Digoxin
  • Beta Blockers
  • Ca Channel Blockers
  • Na Channel Blockers
42
Q

What drugs are used for Bradyarrythmias?

A

Propranolol, Atenolol

43
Q

What receptors do Beta Blockers used?

A

Adrenoreceptor antagonists

44
Q

What occurs when Beta Blockers are used?

A

Block sympathetic stimulation of the heart allowing the parasympathetic system to dominate.

45
Q

What do Beta Blockers lead to?

A

Leading to reduced HR (gallop rhythms in hyperthyroid cats)

46
Q

What does the Propanolol do?

A

Blocks the Beta-2 receptors in respiratory tract -> bronchoconstriction avoid in cats.

47
Q

What drug is used for Ca Channel Blockers?

A

Diltiazem - Hypercard

48
Q

How is Ca channel blockers used?

A

Blocks entry of Ca into the cell.

  • Decreases strength of contraction and HR
  • Vasodilation - care: hypotension.
49
Q

Why is Ca channel blockers useful in cats?

A

Useful in cats with HCM (Hypertrophic Cardiomyopathy).

  • Reduced HR
  • Improved diastolic filling
50
Q

What drugs are used for Na Channel Blockers?

A
  • Lidocaine

- Procainamide

51
Q

What are the side effect of Na Channel Blockers?

A
  • Reduced contractility
  • Reduced Cardiac output
  • Cardiac standstill
  • Neurological: Depression, muscle tremors, convulsions
  • Nausea and V+
52
Q

What drugs are used in Antimuscarinics?

A
  • Atropine

- Glycopyrrolate

53
Q

When is this Antimuscarinics used?

A

To treat bradyarrhythmias due to high vagal tone

54
Q

What are Anti-thrombotics used for?

A
  • Reduced platelet function and aggregation
  • Aspirin
  • Clopidogrel
    ‘Studies have shown that this is more effective than low dose aspirin’
55
Q

Name 5 types of Respiratory Drugs?

A
  • Bronchodilators
  • Antitussives
  • Mucolytics/Expectorants
  • Decongestants
  • Respiratory Stimulants
56
Q

What is Bronchodilators?

A
  • Stimulation of the parasympathetic nervous system.
  • Histamine release in airway inflammation
  • Beta Blockers e.g. propranolol
57
Q

What causes Bronchospasms?

A

Dilate Bronchi and Bronchioles

58
Q

What is Theobromine Poisoning|?

A
  • Slow liver metabolisms of these drugs in dogs.

CHOCOLATE

59
Q

What are the symptoms of Theobromine poisoning?

A

Tachycardia, excitement, tremors, Arrhythmias, V+

60
Q

What are Antitissives and where do they act?

A
Opiates e.g. butorphanol, codeine.
Centrally acting (medulla) - Kidneys.
61
Q

What are the negative side effects of Antitissives?

A
  • Nausea, Sedation, Mucus retention in productive coughs.
62
Q

What are Mucolytics?

A

Make mucus more fluid like and improves clearance.

May improve antibiotic penetration.

63
Q

What are Expectorants?

A

They increase respiratory tract secretions to increase fluid component of secretions.
- e.g. saline, eucalyptus oil

64
Q

What drug is for respiratory stimulants?

A

Doxapram Hydrocholride, stimulates peripheral chemoreceptors

65
Q

What are the indications of respiratory stimulants?

A
  • neonatal asyphixia
  • drug induced depression
  • hypercapnea with respiratory disease.