B2.1 RAS drugs

Question 1

Give examples of ACE inhibitors & their function

Answer 1

captopril
enalapril
lisinopril
fosinopril
ramipril

inhibit formation of angiotensin II by preventing conversion of angiotensin I

Question 2

Give examples of Angiotensin receptor blocking drugs

Answer 2

losartan
valsartan
irbesartan
Candesartan

Question 3

Mechanism of action of AT1R

benefits of AT1R vs ACE inhibitors

Answer 3

Dont prevent formation of AngII but prevent it from binding to receptor

AT1R- dont decrease AngII levels
Dont cause cough

Question 4

Renin inhibitors
name benefit
give example of first and second generation inhibitors

Answer 4

~more specific inhibitors of RAS than ACE
1st gen: enalkiren, remkiren - poor bioavailability due to peptide structure & poor availability in circulation

2nd gen: FK906, zamkiren, aliskiren - are non-peptides. Since 2012 aliskiren is the only renin inhibitor on the market.

Question 5

Mechanism of action Renin inhibitors

Answer 5

(similar to ACE) lower BP
Reduce AngI levels
~no cough
not as widely used unsure of effectivy & side effects

Question 6

Clinical uses of RAS drugs

Answer 6

ACE Inhibitors and ARB’s used in:
Heart Failure – improve exercise tolerance and reduce mortality. Usually combined with a diuretic.
Hypertension
M.I.
For treatment of HF, current BNF guidelines recommend an ACE inhibitor plus beta blocker to achieve improved LV function and exercise tolerance. This is usually combined with a diuretic

Question 7

How would you treat

1. Hypertension
2. Heart Failure

Answer 7

1. Hypertension
   Caucasians – ACE inhibitors or ARBs. If these are not tolerated then beta-blocker
   Afro-caribbeans – do not respond well to ACE inhibitors. Use Ca2+ channel blockers.
2. Heart Failure
   ACE inhibitor and beta blocker plus diuretic.