What is a potential serious reaction that requires immediate medical attention while on Irbesartan?

Hyperkalemia, or elevated potassium levels in the blood, is a potential serious reaction associated with the use of Irbesartan. As an angiotensin II receptor blocker (ARB), Irbesartan can disrupt the renin-angiotensin system, leading to impaired renal excretion of potassium. The accumulation of potassium can result in a range of complications, including heart irregularities and potential cardiac arrest if not addressed quickly. Therefore, patients on Irbesartan must be monitored regularly for potassium levels, and any indication of hyperkalemia warrants immediate medical intervention to prevent severe health risks.

In contrast, while pneumonia, anemia, and diabetes may have clinical relevance, they are not known to be direct or immediate serious reactions stemming from Irbesartan use. Monitoring potassium levels is essential for safety during treatment with this medication.