Antihypertensive Medications and the Prevalence of Hyperkalemia in a Large Health System

Abstract

Little is known about the frequency and patterns of hyperkalemia in clinical settings. We evaluated the association between baseline antihypertensive medications that may affect potassium levels (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, loop/thiazide diuretics, and potassium-sparing diuretics) and hyperkalemia, defined by potassium >5 mEq/L and >5.5 mEq/L, over a 3-year time period in 194 456 outpatients in the Geisinger Health System, as well as actions taken after an episode of hyperkalemia. The proportions of patients with 0, <2, 2 to 4, and ≥4 potassium measurements per year were 20%, 58%, 16%, and 6%. Potassium levels >5 mEq/L and >5.5 mEq/L occurred in 10.8% and 2.3% of all patients over the 3-year period; among patients with ≥4 measurements per year, corresponding values were 39.4% and 14.6%. Most cases of hyperkalemia occurred only once during follow-up. The antihypertensive medication class most strongly associated with hyperkalemia was angiotensin-converting enzyme inhibitors. Among patients with a measurement of potassium >5.5 mEq/L, only 24% were seen by a nephrologist and 5.2% were seen by a dietician during the 3-year period. Short-term actions after a potassium measurement >5.5 mEq/L included emergency room visit (3.1% within 7 days), remeasurement of potassium (44.3% with 14 days), and change in a potassium-altering medication (26.4% within 60 days). The most common medication changes were discontinuation/dose reduction of an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or potassium-sparing diuretic, which occurred in 29.1% and 49.6% of people taking these medications, respectively. In conclusion, hyperkalemia is common. Future research may enable optimal renin-angiotensin-aldosterone system inhibitor use with improved management of hyperkalemia.

Keywords: antihypertensive; hyperkalemia; medications; potassium; renin–angiotensin–aldosterone system.

Figure 1. Proportion Experiencing Transient, Intermittent, and Persistent Hyperkalemia over 3 Years, by Frequency of Potassium Testing

Frequency of serum potassium measurements per year was classified as <2, 2 to <4, and ≥4. Pattern of hyperkalemia was defined as transient (one occurrence), intermittent more than one occurrence but ≤50% of the time), and persistent (>50% of the time).

Figure 2. Proportion Ever Experiencing Hyperkalemia over 3-Years, by eGFR and Frequency of Potassium Testing

Frequency of serum potassium measurements per year was classified as <2, 2 to <4, and ≥4.

Figure 3. Risk of Hyperkalemia associated with Anti-hypertensive Medication Classes

Estimates are adjusted for age, sex, race, estimated glomerular filtration rate, diabetes, hypertension, congestive heart failure. atherosclerotic cardiovascular disease, non-steroid anti-inflammatory drugs, blood pressure, BMI, and number of potassium measurements per year.