Can irbesartan (angiotensin II receptor antagonist) be skipped if experiencing hypotension?

Management of Irbesartan in Hypotension

Irbesartan should be temporarily discontinued if a patient experiences hypotension, as hypotension is a recognized contraindication to continuing angiotensin II receptor blocker (ARB) therapy. 1

Rationale for Discontinuation

Angiotensin II receptor blockers like irbesartan work by blocking the vasoconstricting and aldosterone-secreting effects of angiotensin II, which leads to:

• Vasodilation
• Decreased peripheral resistance
• Reduced blood pressure

When a patient already has hypotension, continuing ARB therapy can:

• Exacerbate the hypotension
• Lead to inadequate organ perfusion
• Potentially cause syncope or falls
• Worsen renal function

Evidence-Based Approach

The American College of Cardiology/American Heart Association guidelines clearly identify hypotension as a contraindication for ARB therapy 1. Specifically:

• ARBs should be used with caution in patients with very low systemic blood pressure (systolic blood pressure less than 80 mm Hg) 1
• Hypotension is listed as a specific contraindication for ARBs in the ACC/AHA guidelines 1
• Treatment with ARBs should not be initiated in hypotensive patients who are at immediate risk of cardiogenic shock 1

Management Algorithm

1. Assess the severity of hypotension:

   • If systolic BP < 90 mmHg or symptomatic hypotension (dizziness, lightheadedness)
   • If patient shows signs of inadequate organ perfusion

2. Temporarily discontinue irbesartan if either of the above conditions is present

3. Identify and treat underlying cause of hypotension:

   • Volume depletion (provide fluid resuscitation)
   • Sepsis
   • Cardiac dysfunction
   • Medication effects (other antihypertensives)

4. Monitor blood pressure until stabilized

5. Consider reintroduction once blood pressure normalizes:

   • Start at lower dose (75-150 mg instead of 300 mg)
   • Monitor blood pressure closely after reintroduction
   • Titrate slowly based on blood pressure response

Special Considerations

• Heart Failure Patients: Despite the importance of RAAS blockade in heart failure, hypotension takes precedence as a safety concern 1

• Renal Function: Monitor renal function when restarting therapy, as ARBs can affect renal perfusion, especially in patients with bilateral renal artery stenosis 1

• Elderly Patients: More susceptible to hypotension with ARBs; use lower starting doses when reinitiating 2

Common Pitfalls to Avoid

• Continuing ARB despite hypotension: This can lead to worsening hypotension and end-organ damage

• Abrupt discontinuation without a plan to reassess: ARBs provide important cardiovascular and renal protection, so have a clear plan to reassess and potentially reintroduce

• Failure to adjust other antihypertensives: When restarting irbesartan, consider whether other antihypertensive medications need dose adjustment

• Inadequate monitoring: Blood pressure and renal function should be closely monitored when discontinuing and reintroducing ARB therapy

By following these evidence-based guidelines, clinicians can appropriately manage irbesartan therapy in the setting of hypotension while minimizing risks to the patient.