Why is monitoring potassium levels essential while a client is on losartan?

Monitoring potassium levels while a client is on losartan is essential particularly because the medication can impact the heart's conduction system. Losartan is an angiotensin II receptor antagonist often used to treat hypertension and heart failure. One of the side effects of losartan is the potential for hyperkalemia, or elevated potassium levels, which can lead to serious cardiac complications, including arrhythmias. High potassium levels can disrupt the normal electrical activity of the heart, making it critical to monitor these levels regularly to prevent dangerous cardiac events.

Additionally, while losartan does help regulate blood pressure and may have implications for renal function, the most immediate risk when considering the medication's effects is its influence on potassium levels, directly related to cardiac health.