When to withhold irbesartan (Angiotensin II receptor antagonist) in patients with hypotension (low blood pressure)?

From the Guidelines

Irbesartan should be withheld if systolic blood pressure drops below 90 mmHg or if the patient experiences symptoms of hypotension such as dizziness, lightheadedness, or fainting, as recommended by the most recent guidelines 1. For patients with chronic kidney disease or heart failure, a slightly higher threshold of 100 mmHg systolic may be appropriate.

Key Considerations

• If a patient misses a dose due to low blood pressure, they should not double the next dose but instead resume their regular dosing schedule when blood pressure returns to safe levels.
• Patients should monitor their blood pressure regularly while taking irbesartan, ideally at the same time each day.
• Irbesartan works by blocking angiotensin II receptors, causing blood vessel relaxation and lowering blood pressure, which can lead to excessive drops in blood pressure, especially when starting therapy, increasing the dose, or when combined with other blood pressure medications, diuretics, or during periods of dehydration 1.

Patient Guidance

• Patients should contact their healthcare provider immediately if they experience severe dizziness, fainting, or persistent low blood pressure readings.
• Before starting or intensifying BP-lowering medication, it is recommended to test for orthostatic hypotension, by first having the patient sit or lie for 5 min and then measuring BP 1 and/or 3 min after standing 1.

Clinical Decision Making

• The decision to withhold irbesartan should be based on individual patient factors, including the presence of chronic kidney disease, heart failure, or other comorbidities, as well as the patient's overall clinical condition 1.
• In patients with lower blood pressure, alternative treatments such as ivabradine, ranolazine, or trimetazidine may be preferable 1.

From the FDA Drug Label

5.2 Hypotension in Volume- or Salt-Depleted Patients In patients with an activated renin-angiotensin system, such as volume- or salt-depleted patients (e. g. those being treated with high doses of diuretics), symptomatic hypotension may occur after initialization of treatment with irbesartan. Correct volume or salt depletion prior to administration of irbesartan or use a lower starting dose [see Dosage and Administration (2.4)]. The decision to withhold irbesartan for low blood pressure should be based on the presence of symptomatic hypotension in patients who are volume- or salt-depleted.

• Withhold irbesartan in patients with symptomatic hypotension.
• Correct volume or salt depletion prior to administration of irbesartan or use a lower starting dose. 2

From the Research

Withholding Irbesartan for Low Blood Pressure

• The decision to withhold irbesartan for low blood pressure should be based on individual patient factors, such as the severity of hypotension and the presence of other medical conditions 3.
• In general, irbesartan is well-tolerated and effective in reducing blood pressure, even in patients with primary hypertension who miss a dose 3.
• However, in patients with severe hypotension, it may be necessary to withhold irbesartan or adjust the dose to avoid exacerbating the condition.
• The studies reviewed did not provide specific guidance on when to withhold irbesartan for low blood pressure, but they did demonstrate the efficacy and safety of irbesartan in reducing blood pressure in patients with hypertension 4, 5, 6, 7.

Factors to Consider

• The severity of hypotension: patients with severe hypotension may require withholding irbesartan or adjusting the dose.
• The presence of other medical conditions: patients with certain medical conditions, such as heart failure or renal impairment, may require closer monitoring and adjustment of irbesartan therapy.
• The patient's response to irbesartan: patients who experience significant reductions in blood pressure with irbesartan may require dose adjustments or withholding of the medication.

Monitoring and Adjustment

• Patients taking irbesartan should be monitored regularly for changes in blood pressure and adjusted as needed to avoid hypotension 3.
• The dose of irbesartan can be adjusted based on individual patient response and the presence of other medical conditions.
• In patients with severe hypotension, alternative antihypertensive medications may be considered.