ACE Inhibitors

Question 1

What are ACE-Is used for?

Answer 1

Angiotensin-converting enzyme (ACE) inhibitors are now the established first-line treatment in younger patients with hypertension and are also extensively used to treat heart failure. They are known to be less effective in treating hypertensive Afro-Caribbean patients. ACE inhibitors are also used to treat diabetic nephropathy and have a role in the secondary prevention of ischaemic heart disease.

Question 2

Mechanism of action ACEI?

Answer 2

inhibit the conversion angiotensin I to angiotensin II

ACE inhibitors are activated by phase 1 metabolism in the liver

Question 3

Side effects ACEI?

Answer 3

cough - occurs in around 15% of patients and may occur up to a year after starting treatment, thought to be due to increased bradykinin levels
angioedema: may occur up to a year after starting treatment
hyperkalaemia
first-dose hypotension: more common in patients taking diuretics

Question 4

Cautions and contraindications of ACEI?

Answer 4

pregnancy and breastfeeding - avoid
renovascular disease - may result in renal impairment
aortic stenosis - may result in hypotension
hereditary of idiopathic angioedema
specialist advice should be sought before starting ACE inhibitors in patients with a potassium >= 5.0 mmol/L

Question 5

Interactions ACEI?

Answer 5

patients receiving high-dose diuretic therapy (more than 80 mg of furosemide a day)

• significantly increases the risk of hypotension

Question 6

Monitoring with ACEI?

Answer 6

urea and electrolytes should be checked before treatment is initiated and after increasing the dose
- a rise in the creatinine and potassium may be expected after starting ACE inhibitors
- acceptable changes are an increase in serum creatinine, up to 30% from baseline and an increase in potassium up to 5.5 mmol/l.
- significant renal impairment may occur in patients who have undiagnosed bilateral renal artery stenosis

Question 7

Management of hypertension?

Answer 7