From the Guidelines
The patient's acute kidney injury (AKI) and hypokalemia are likely related to their antihypertensive medication, and I recommend temporarily discontinuing both olmesartan and hydrochlorothiazide while initiating intravenous fluids for volume repletion and potassium supplementation based on severity of hypokalemia. Olmesartan, an angiotensin II receptor blocker, can cause AKI particularly in settings of volume depletion or renal artery stenosis, as noted in the 2018 guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1. Hydrochlorothiazide, a thiazide diuretic, commonly causes hypokalemia through increased urinary potassium excretion, as seen in the same guideline 1 and further discussed in 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 combination therapy may have created a "perfect storm" for these adverse effects, especially if the patient experienced dehydration, was taking NSAIDs, or had underlying renal issues. After stabilization, renal function and electrolytes should be closely monitored, with consideration of alternative antihypertensive medications that have lower risk of these complications, such as calcium channel blockers, as suggested by the most recent standards of care in diabetes-2025 1. When renal function improves, a careful rechallenge with lower doses or different agents may be considered based on the patient's blood pressure control needs. Key considerations include monitoring serum creatinine and potassium levels after initiation of treatment with an ACE inhibitor or ARB, MRA, or diuretic, and during treatment, particularly among individuals with reduced glomerular filtration who are at increased risk of hyperkalemia and AKI 1. The choice of alternative antihypertensive medications should be guided by the patient's specific clinical profile and the potential risks and benefits associated with each medication class, as outlined in the available guidelines 1.
From the FDA Drug Label
5.4 Impaired Renal Function As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function may be anticipated in susceptible individuals treated with olmesartan medoxomil. 5.6 Hyperkalemia Serum potassium should be monitored in patients receiving olmesartan medoxomil. Drugs that inhibit the renin angiotensin system can cause hyperkalemia 7.1 Agents Increasing Serum Potassium Concomitant use of olmesartan with other agents that block the renin-angiotensin system, potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride), potassium supplements, salt substitutes containing potassium or other drugs that may increase potassium levels (e.g., heparin) may lead to increases in serum potassium.
The patient's Acute Kidney Injury (AKI) and hypokalemia may be related to the use of Olmesartan and Hydrochlorothiazide.
- Olmesartan can cause changes in renal function, including AKI, especially in susceptible individuals.
- Hydrochlorothiazide is a diuretic that can cause hypokalemia. However, the combination of Olmesartan and Hydrochlorothiazide is not directly addressed in the provided drug labels regarding the development of AKI and hypokalemia. Given the potential risks associated with Olmesartan and Hydrochlorothiazide, it is essential to closely monitor the patient's renal function and electrolyte levels 2, 2.
From the Research
Patient Presentation
- The patient is taking Olmesartan 20 Mg + Hydrochlorothiazide 12.5 Mg Tablets and presents with Acute Kidney Injury (AKI) and hypokalemia.
Hypokalemia Association with Hydrochlorothiazide
- Hydrochlorothiazide, a thiazide diuretic, is known to contribute to hypokalemia due to increased urinary potassium loss 3, 4.
- The use of hydrochlorothiazide can lead to mild, asymptomatic hypokalemia, which is associated with an increased risk of major adverse cardiovascular events if left untreated 3.
- Factors associated with hypokalemia in hydrochlorothiazide users include female sex, non-Hispanic black ethnicity, underweight, and long-term therapy 4.
Combination Therapy with Olmesartan
- The combination of olmesartan, an angiotensin II receptor blocker (ARB), with hydrochlorothiazide is known to be effective in treating hypertension 5.
- While ARB use can oppose hypokalemia triggered by hydrochlorothiazide, the combination therapy may still be associated with hypokalemia in some cases 6.
Acute Kidney Injury and Dyskalemias
- Dyskalemias, including hypokalemia, are common in patients with AKI and are independent predictors of adverse outcomes 7.
- Hyperkalemia and profound hypokalemia are associated with prolonged length of stay and in-hospital mortality in patients with AKI 7.
- Potassium-sparing diuretics, ACE inhibitors, AKI stage, and underlying chronic kidney disease are predictors of hyperkalemia in AKI, but the relationship between these factors and hypokalemia is less clear 7.