Risk is high in Patients with decreased left ventricular function Patients taking digoxin Patients with diabetes (in whom insulin concentrations can fluctuate) Patients with asthma who are taking beta 2-agonists Triamterene 100 mg orally once a day or spironolactone 25 mg orally 4 times a day does not increase potassium excretion and may be useful in patients who become hypokalemic but must use diuretics.