Anti-Hypertensives/Heart Failure/Angina Flashcards
What are the 4 first-line classes of drug therapy used in hypertension?
ACE inhibitors
Angiotensin II Receptor Blockers
Calcium channel blockers
Diuretics
Who would be better suited to a calcium channel blocker or diuretic as opposed to an ACE inhibitor?
People aged 55 or older
Black patients
What is the mechanism of action of ACE inhibitors?
Competitively inhibit angiotensin converting enzyme - therefore reduce formation of angiotensin II, a potent vasoconstrictor, and also decrease aldosterone levels.
Do ACE inhibitors act mainly in arteries or veins?
Arteries
List 4 ADRs of ACE inhibitors
Dry cough
Angioedema
Renal failure
Hyperkalaemia
Give 2 examples of ACE inhibitors
Ramipril
Lisinopril
Give 2 examples of Angiotensin receptor blockers
Losartan
Candesartan
What is the mechanism of action of angiotensin receptor blockers?
Bind to angiotensin AT1 receptors
Inhibit action of angiotensin II
Why is there no dry cough with angiotensin receptor blockers?List 2 important ADRs that may occur.
No build up of bradykinin
Hyperkalaemia
Renal failure
What is the mechanism of action of calcium channel blockers?
Bind to L-type calcium channels in the heart and smooth muscle of coronary/peripheral arterioles
Reduces calcium entry into cell - prevents contraction and hence constriction
Therefore vasodilates arteries (no effect on veins) - lowers TPR and improves blood supply to heart
List 3 examples of calcium channel blockers
Verapamil
Diltiazem
Amlodipine
Give 4 ADRs of Verapamil
- Constipation
- Bradycardia
- 1st degree heart block
- Negative inotropy
Give 2 side effects of Diltiazem
- Small risk of bradycardia
- Some negative inotropy
Give 4 ADRs of Amlodipine
Any 4 of:
- Baroreceptor-mediated tachycardia/palpitations
- Flushing
- Sweating
- Throbbing headache
- Oedema
List some secondary classes of drug used to treat hypertension
- Alpha-adrenoreceptor blockers
- B-blockers
- Renin inhibitors
- Centrally acting agents
- Vasodilators
Give an example of an alpha-adrenoreceptor blocker
Doxazosin
Give 4 ADRs of Doxazosin
Postural hypotension
Dizziness
Headache
Oedema
What is the mechanism of action of B-blockers?
- Block B-adrenoreceptors in heart - reduce cardiac output
- Block renin release in kidney - down-regulate RAAS
Which B-blocker is not selective for B1 receptors?
Why is this significant?
Propranolol
Contraindicated in asthma. The others can be used with caution.
List 4 ADRs of B-blockers
- Lethargy
- Bradycardia
- Impaired glucose tolerance
- Raynaud’s
Name a renin inhibitor
Aliskiren
Name 4 B-blockers
Propranolol
Bisoprolol
Atenolol
Sotalol
What are the mechanisms by which drugs act to improve prognosis in heart failure?
Which other drugs are used purely for symptom control?
- RAAS antagonism
- B-blockers
- Positive inotropes - cardiac glycosides, B agonists
- Diuretics
Name a cardiac glycoside.
State its mechanism of action
Digoxin
Blocks Na+/K+-ATPase - reduces Na+ extrusion from cells, therefore reduces conc gradient down which Na+ flows into cell via NCX. Hence less Ca2+ leaves cell via NCX - more for contraction –> positive inotropy.
