If a client on losartan presents with a serum potassium level of 5.9 mEq/L, what should the nurse do first?

In this scenario, the client is on losartan, an angiotensin II receptor blocker known to potentially cause hyperkalemia, which is an elevated potassium level in the serum. A serum potassium level of 5.9 mEq/L is considered significantly high and is above the normal range (typically 3.5 to 5.0 mEq/L).

The first step in managing a client with hyperkalemia is to withhold any medications that may further increase potassium levels or contribute to the condition. Since losartan can lead to increased potassium retention, withholding the scheduled dose is vital to prevent any worsening of the hyperkalemia.

Following this action, it will be important to perform additional assessments and notify the healthcare provider, as hyperkalemia can lead to serious complications, including cardiac dysrhythmias. However, immediately addressing the potential for further elevation of potassium through the medication is the priority step.