What is the concern with a 78-year-old male with hyperkalemia on lisinopril with impaired renal function?

From the Guidelines

For a 78-year-old male with elevated potassium of 5.3, currently on lisinopril, who is asymptomatic with a GFR of 60, I recommend reducing the lisinopril dose or considering an alternative antihypertensive medication that doesn't affect potassium levels, such as a thiazide diuretic like hydrochlorothiazide, as suggested by the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1. This patient has mild hyperkalemia likely caused by the ACE inhibitor (lisinopril), which blocks aldosterone production and reduces potassium excretion. While this level of hyperkalemia is concerning but not immediately dangerous, it should be addressed to prevent further elevation. The patient should have his potassium rechecked within 1-2 weeks after medication adjustment. Additionally, he should be advised to:

• Limit high-potassium foods such as bananas, oranges, potatoes, and tomatoes
• Avoid potassium-based salt substitutes
• Maintain adequate hydration The moderate kidney function impairment (GFR of 60) is likely contributing to reduced potassium clearance, making him more susceptible to medication-induced hyperkalemia. If potassium levels continue to rise despite these interventions, a diuretic like hydrochlorothiazide might be added to enhance potassium excretion, as it is a preferred diuretic in patients with mild kidney function impairment, according to the European Heart Journal expert consensus document on the management of hyperkalaemia in patients with cardiovascular disease treated with renin angiotensin aldosterone system inhibitors 1. It is also important to consider the use of potassium binders, such as patiromer sorbitex calcium (Veltassa) or sodium zirconium cyclosilicate (SZC), which have been shown to be effective in reducing potassium levels in patients with hyperkalemia, as reported in the European Heart Journal expert consensus document 1. However, the use of these agents should be individualized and based on the patient's specific clinical needs and medical history. In general, the management of hyperkalemia should be guided by the severity of the condition, the presence of symptoms, and the underlying cause of the hyperkalemia, as well as the patient's kidney function and other comorbidities, as recommended by the American College of Cardiology/American Heart Association task force on clinical practice guidelines 1.

From the FDA Drug Label

Monitor renal function periodically in patients treated with lisinopril. Changes in renal function including acute renal failure can be caused by drugs that inhibit the renin-angiotensin system. Patients whose renal function may depend in part on the activity of the renin-angiotensin system (e.g., patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure, post-myocardial infarction or volume depletion) may be at particular risk of developing acute renal failure on lisinopril. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on lisinopril [see Adverse Reactions (6. 1), Drug Interactions (7.4)].

The patient has a GFR of 60, which indicates chronic kidney disease. The patient is also on lisinopril, which can cause changes in renal function, including acute renal failure.

• Key points:
  • The patient's renal function should be monitored periodically.
  • The patient may be at particular risk of developing acute renal failure on lisinopril due to their chronic kidney disease.
  • Withholding or discontinuing lisinopril therapy should be considered if the patient develops a clinically significant decrease in renal function. Given the patient's asymptomatic status and GFR of 60, it is essential to closely monitor their renal function while on lisinopril therapy 2, 2.

From the Research

Patient Profile

• Age: 78 years
• Serum potassium level (K): 5.3 mmol/L
• Medication: Lisinopril
• Asymptomatic
• Glomerular filtration rate (GFR): 60 ml/min/1.73 m(2)

Hyperkalemia Risk

• According to the study 3, the risk of hyperkalemia increases gradually with declining eGFR, but there is no apparent threshold for contraindicating ACE-inhibitors like lisinopril.
• The study 3 also identified predictors of hyperkalemia, including age, eGFR, diabetes, heart failure, potassium supplements, potassium-sparing diuretics, and high dose of ACE-inhibitor.
• The patient's serum potassium level is 5.3 mmol/L, which is below the threshold for hyperkalemia (>5.5 mmol/L) defined in the study 3.

Optimal Potassium Levels

• The study 4 suggests that optimal potassium levels in patients with heart failure should be between 4-5 mmol/L.
• However, this study does not provide direct guidance for patients with chronic kidney disease (CKD) like the one described.

Management of Hyperkalemia

• The study 5 discusses the management of hyperkalemia in patients with end-stage renal disease (ESRD) on maintenance dialysis, which is not directly applicable to this patient.
• The study 6 found that hyperkalemia is associated with diabetes mellitus, diminished renal function, and the use of angiotensin-converting enzyme inhibitors, but it does not provide guidance on managing hyperkalemia in patients with CKD.
• The study 7 found that low-dose spironolactone can provide additive blood pressure reduction in CKD patients with resistant hypertension, but it also notes that hyperkalemia can occur with the use of spironolactone.