Angiotensin antagonists

Question 1

Indications ?

Answer 1

They are usually used as an alternative treatment to the ACE inhibitors when the dry cough side effect cannot be tolerated. Indications are the same as those of ACE inhibitors : HTA, insuffisance cardiaque, maladies cardiaques ischemiques, nephropathie diabetique et maladie renale chroniques avec proteinurie.

Question 2

Mechanism of action ?

Answer 2

Instead of inhibiting the conversion, they block the action of angiotensin at AT1 receptors.
They increase the peripheral vascular resistance (afterload) and promote the excretion of water &Na (preload). They cause a fall in the blood pressure due to reducing the vascular resistance but also to dilating the efferent arteriole which releases the intra-glomerular pressure.

Question 3

Important AE ?

Answer 3

hypotension, hyperkalemia &renal failure. Patients with renal stenosis are particularly susceptible to having their renal function alterated by angiotensin inhibitors, because they rely on the constriction of their efferent arteriole to maintain the correct glomerular filtration.
Dry cough &angioedema aren’t common with angiotension antagonists.

Question 4

Important cautions ?

Answer 4

Angiotensin antagonists are not to administer in patients with renal stenosis or acute renal injury, in pregnant or potentially becoming pregnant and lactating women.
No to associate with hyperkalemic drugs &with NSAIDs.

Question 5

Communication ?

Answer 5

Explain to patient that this is a drug to lower their blood pressure &reduce the strain on their heart, &that it has been alternated to a previous treatment due to dry cough/angioedema. Also, that a risk of renal failure is a possibility which urges for electrolytes &renal profile monitoring.

Question 6

Famous angiotensin antagonists names ?

Answer 6

VALSARTAN, CANDESARTAN, LOSARTAN, IRBESARTAN.

Question 7

How are sartans taken ?

Answer 7

Orally, once daily, starting doses for heart failure is lower than in other indications. Losartan : 12,5 mg for heart failure, 50mg in other indications. This dose is titrated up to a maximum of 100 mg. Best to take the first dose before bed time to avoid the symptomatic hypotension side effect.