Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

RBF: 1) Drugs > Lecture 11 - Alpha blockers and calcium channel blockers > Flashcards

Lecture 11 - Alpha blockers and calcium channel blockers Flashcards

1
Q

What is the mechanism of action for alpha blockers?

A

These drugs block the effects of sympathetic nerves on blood vessels by binding to alpha-adrenoreceptors located on vascular smooth muscle. Basically these drugs stop the contraction of smooth muscle on the blood vessels, hence causing dilation (not contraction which normally happens).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List alpha blockers?

A
  1. Doxazosin.
  2. Proazosin.
  3. Terazosin.
  4. Phenoxybenzamine.
  5. Phentolamine.
  6. Labetalol.
  7. Carvedilol.
  8. Tamsulosin.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are alpha blockers used for?

A
  1. Hypertension.
  2. Vasoconstriction.
  3. Raynaud’s disease.
  4. Pheochromocytoma.
  5. Erectile dysfunction.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe doxazosin?

A

Selective oral reversible alpha-1 blocker that acts on post-sympathetic receptors. It is mainly a vasodilator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is doxazosin used for?

A
  1. Hypertension.

2. Benign prostatic hyperplasia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why do patients not take doxazosin?

A
  1. History of postural hypotension.
  2. Pulmonary oedema due to aortic or mitral stenosis.
  3. Heart failure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the adverse effects of doxazosin?

A
  1. Dry mouth.
  2. GI disturbances.
  3. Hypotension.
  4. Oedema.
  5. Syncope.
  6. Tachycardia.
  7. SOB.
  8. Drowsiness.
  9. Sleep disturbances.
  10. Headache.
  11. Lassitude - mental or physical weariness.
  12. Nasal stuffiness.
  13. Urinary incontinence in women.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe phenoxybenzamine?

A

Non-selective oral irreversible alpha blocker that is a H1, ACh, 5HT antagonist as well.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is phenoxybenzamine used for?

A
  1. Phaeochromocytoma.

2. Hypertension.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why do patients not take phenoxybenzamine?

A

They do not take if they have the following:

  1. History of cerebrovascular accident.
  2. Conditions where sudden drop in BP is undesirable (e.g. stroke or MI).
  3. Congestive heart failure.
  4. Severe ischaemic heart disease.
  5. Cerebrovascular disease.
  6. Renal impairment.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the adverse effects of phenoxybenzamine?

A
  1. Postural hypotension.
  2. Dizziness.
  3. Compensatory tachycardia.
  4. Lassitude.
  5. Nasal congestion.
  6. Miosis.
  7. Impotence - inhibition to ejaculate.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe phentolamine?

A

It is an intravenous alpha blocker that cannot be absorbed orally. It is a competitive antagonist for both alpha receptors (causes an increase in NE release) and it is also a: 5Ht, muscarinic H1 and H2 antagonist.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is phentolamine used for?

A

Hypertensive episodes due to pheochromocytoma.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why do patients not take phentolamine?

A

They do not take if they have the following:

  1. Hypotension.
  2. History of MI.
  3. Coronary insufficiency.
  4. Angina.
  5. Coronary artery disease.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the adverse effects of phentolamine?

A
  1. Postural hypotension.
  2. Tachycardia.
  3. Dizziness.
  4. Flushing.
  5. Nausea.
  6. Vomiting.
  7. Diarrhoea.
  8. Nasal congestion.
  9. Angina.
  10. Chest pain.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe labetalol?

A

It is both an alpha and beta blocker.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is labetalol used for?

A
  1. Hypertension (even in pregnancy).

2. Angina following acute MI.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why do patients not take labetalol?

A

They do not take if they have the following:

  1. Asthma.
  2. Uncontrolled heart failure.
  3. Marked bradycardia.
  4. Hypotension.
  5. 2nd or 3rd degree AV block.
  6. Cardiogenic shock.
  7. Metabolic acidosis.
  8. Severe peripheral arterial disease.
  9. Hepatic injury.
19
Q

What are the adverse effects of labetalol?

A
  1. Postural hypotension.
  2. Tiredness.
  3. Weakness.
  4. Headache.
  5. Rash.
  6. Scalp tingling.
  7. Difficulty with micturition.
  8. Epigastric pain.
  9. Nausea and vomiting.
  10. Liver damage.
20
Q

Describe carvedilol?

A

Alpha and beta blocker.

21
Q

What is carvedilol used for?

A
  1. Hypertension.
  2. Angina.
  3. Left ventricular dysfunction following MI.
  4. Congestive heart failure.
22
Q

Why do patients not take carvedilol?

A

They do not take if they have the following:

  1. Asthma.
  2. Acute or decompensated heart failure requiring inotropes.
  3. Hypotension.
  4. Marked bradycardia.
  5. 2nd or 3rd degree AV block.
  6. Cardiogenic shock.
  7. Metabolic acidosis.
  8. Pregnant.
  9. Hepatic impairment.
23
Q

What are the adverse effects for carvedilol?

A
  1. Postural hypotension.
  2. Dizziness.
  3. Headache.
  4. Fatigue.
  5. GI disturbances.
  6. Bradycardia.
  7. Peripheral oedema.
  8. Dry mouth.
  9. Dry eyes.
  10. Disturbed vision.
  11. Impotence.
  12. Micturition disturbance.
  13. Influenza like symptoms.
  14. AV block.
  15. Nasal stuffiness.
24
Q

Describe tamsulosin?

A

Selective oral alpha-1 blocker that relaxes smooth muscle in the prostate and bladder.

25
Q

What is tamsulosin used for?

A

Benign prostatic hyperplasia.

26
Q

Why do patients not take tamsulosin?

A
  1. History of postural hypotension and micturition syncope.
  2. Hepatic impairment.
  3. Caution with eGFR <10mL/min.
27
Q

What are the adverse effects of tamsulosin?

A
  1. Dry mouth.
  2. GI disturbances.
  3. Hypotension.
  4. Oedema.
  5. Syncope.
  6. Tachycardia.
  7. Palpitations.
  8. Rhinitis.
  9. Dizziness.
  10. Depression.
28
Q

What is the mechanism of action for calcium channel blockers?

A

Calcium channel blockers inhibit voltage-dependent L-type calcium channels, thus stopping the influx of calcium into the cell, so stopping a lot of effects:

  1. Contraction of vascular smooth muscle - vasoconstriction.
  2. Increased force of contraction in the cardiac muscle.
  3. Increased HR.
  4. Increased aldosterone production therefore increased BP.
29
Q

List the type of calcium channel blockers?

A
  1. Dihydropyridines.
  2. Phenylalkylamine.
  3. Benzothiazepine.
30
Q

What are calcium channel blockers used for?

A
  1. Hypertension.
  2. Angina.
  3. Arrhythmia - for RATE control.
  4. Vasospasm.
31
Q

Describe Nifedipine?

A

It is an oral dihydropyridine calcium channel blocker that acts primarily on vascular smooth muscle cells by stabilising voltage-gated L type channels in their inactive conformation (inhibits influx of calcium in smooth muscle cells preventing calcium dependent myocyte contraction and vasoconstriction).

32
Q

What is nifedipine used for?

A
  1. Hypertension.
  2. Prophylaxis angina.
  3. Raynaud’s phenomenon.
33
Q

Why do patients not take nifedipine?

A

They do not take if they have the following:

  1. Cardiogenic shock.
  2. Advanced aortic stenosis.
  3. Within one month of MI.
  4. Unstable or acute attacks of angina.
  5. Pregnant.
34
Q

What are the adverse effects of nifedipine?

A
  1. GI disturbance.
  2. Hypotension.
  3. Oedema.
  4. Vasodilation.
  5. Palpitation.
  6. Headache.
  7. Dizziness.
  8. Flushing.
  9. Lethargy.
35
Q

Describe diltiazem?

A

It is an oral benzothiazepine calcium channel blocker with vasodilating actions due to antagonism of calcium ions in membrane functions and some effect on the conducting system (e.g. HR).

36
Q

What is diltiazem used for?

A
  1. Angina.
  2. Hypertension.
  3. AF rate control.
37
Q

Why do patients not take diltiazem?

A

They do not take if they have the following:

  1. Severe bradycardia.
  2. Left ventricular failure with pulmonary congestion.
  3. 2nd or 3rd degree AV block.
  4. Sick sinus syndrome.
  5. Hepatic impairment.
  6. Renal impairment.
  7. Pregnant.
38
Q

What are the adverse effects of diltizem?

A
  1. Bradycardia.
  2. SA block.
  3. AV block.
  4. Palpitations.
  5. Dizziness.
  6. Hypotension.
  7. Oedema.
  8. Rash.
  9. Photosensitivity.
  10. Gynaecomastia.
39
Q

Describe verapamil?

A

Oral/IV phenylalkylamine calcium channel blocker that acts on calcium channels in conducting tissue. They cause slow HR and reduce transmission through AV node (negative chronotrope).

40
Q

What is verapamil used for?

A
  1. Tachyarrhythmias (SVRT).
  2. AF rate control.
  3. Hypertension.
  4. Angina.
41
Q

Why do patients not take verapamil?

A

They do not take if they have the following:

  1. Hypotension.
  2. Bradycardia.
  3. 2nd and 3rd degree AV block.
  4. Sick sinus syndrome.
  5. Cardiogenic shock.
  6. SA block.
  7. History of heart failure.
  8. AF associated with Wolff-Parkinson-White Syndrome.
  9. Ventricular tachycardia.
  10. Hepatic impairment.
  11. Pregnant.
42
Q

What drugs should patients taking verapamil not take?

A
  1. Beta blockers.
  2. Statins - verapamil inhibits cytochrome P450-3A4 so it can cause rhabdomyolysis (break down of muscle if on statins as well).
  3. Digoxin - verapamil inhibits p-glycoproteins so it can increase digoxin concentrations.
43
Q

What are the adverse effects of verapamil?

A
  1. Constipation.
  2. Nausea.
  3. Vomiting.
  4. Flushing.
  5. Headache.
  6. Dizziness.
  7. Ankle oedema.
  8. Myalgia.
  9. Fatigue.
  10. Parasethesia.

RBF: 1) Drugs (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions