The answer is Patients with hyperkalemia.
Potassium-sparing diuretics are diuretic drugs that inhibit the secretion of potassium into the urine. Because of that, they raise potassium levels in the body.
People with hyperkalemia (higher amounts of potassium) can't take potassium-sparing diuretic because it will make potassium levels even higher, making it a risks for fatal arrhythmias.
