Angiotensin 2 antagonists

These medicines are the most recent class of treatment forhypertension. They act by blocking angiotensin 2 receptors by interfering with the renin-angiotensin system, they reduce or inhibit constriction of blood vessels which are responsible for the rise in blood pressure. They can be used alone or in combination with a diuretic.

How do the angiotensin 2 antagonists work?

As their name indicates, angiotensin 2 antagonists block the action of angiotensin 2. Angiotensin 2 has a potent vasoconstricting effect which is responsible for the rise in blood pressure and can then no longer cause arterioles to contract. As a result, these medicines promote vasodilatation and therefore reduce blood pressure.

Do they have any contraindications or precautions?

Angiotensin 2 antagonists have no specific side effects. On the other hand, they are not recommended for use during pregnancy because of a possible risk of teratogenesis, foetal renal failure, and foetal bone retardation.

Sources:

• Merck Manual – 4^th edition;
• French Hypertension Committee ;
• Pharmacorama, 9 June 2011.