Angiotensin II receptor blockers (ARBs) are a class of medications used to treat hypertension, heart failure, and other cardiovascular diseases. ARBs work by blocking the action of angiotensin II, a hormone that plays a key role in regulating blood pressure and fluid balance in the body. In this blog, we will explore the mechanism of action, indications, and side effects of ARBs.

I. Mechanism of Action

Angiotensin ii receptor blockers the action of angiotensin II by selectively binding to the angiotensin II type 1 (AT1) receptor. This prevents angiotensin II from binding to the receptor and exerting its physiological effects, including vasoconstriction, sodium retention, and aldosterone secretion.

Unlike angiotensin-converting enzyme (ACE) inhibitors, which block the production of angiotensin II, ARBs do not affect the breakdown of bradykinin, a vasodilator peptide. This means that ARBs are less likely to cause cough and angioedema, which are common side effects of ACE inhibitors.

II. Indications

ARBs are indicated for the treatment of several cardiovascular conditions, including:

  1. Hypertension: ARBs are commonly used to treat hypertension, either alone or in combination with other antihypertensive medications.

  2. Heart failure: ARBs are used to treat heart failure in patients who cannot tolerate ACE inhibitors or in combination with ACE inhibitors.

  3. Diabetic nephropathy: ARBs are used to slow the progression of diabetic nephropathy, a type of kidney disease that occurs in people with diabetes.

  4. Myocardial infarction: ARBs may be used in patients who cannot tolerate ACE inhibitors after a myocardial infarction (heart attack).

III. Side Effects

Like all medications, ARBs can cause side effects. The most common side effects of ARBs include:

  1. Hypotension: ARBs can cause a decrease in blood pressure, which may lead to dizziness, lightheadedness, or fainting.

  2. Hyperkalemia: ARBs can cause an increase in potassium levels in the blood, which may lead to heart rhythm disturbances.

  3. Renal dysfunction: ARBs can cause renal dysfunction, especially in patients with pre-existing kidney disease.

  4. Angioedema: Although less common than with ACE inhibitors, ARBs can cause angioedema, a swelling of the face, lips, tongue, or throat, which can be life-threatening.

  5. Drug interactions: ARBs may interact with other medications, including potassium-sparing diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), and lithium.

IV. Conclusion

ARBs are an important class of medications used to treat hypertension, heart failure, and other cardiovascular diseases. They work by blocking the action of angiotensin II, a hormone that plays a key role in regulating blood pressure and fluid balance in the body. ARBs have a lower incidence of cough and angioedema compared to ACE inhibitors and are generally well-tolerated. However, like all medications, ARBs can cause side effects and should be used under the guidance of a healthcare provider.