Review Question - QID 212563

An 81-year-old man with a history of congestive heart failure presents to his cardiologist because he has been feeling increasingly short of breath while lying down. Specifically, he says that he is now no longer able to sleep flat on the bed and instead has to be propped up on multiple pillows. In addition, he has been experiencing increased swelling in his legs. Finally, he reports that he has been experiencing muscle cramping and weakness. He reports that he has been taking a diuretic as prescribed and adhering to a low-salt diet. Physical exam reveals crackles on lung auscultation bilaterally and 2+ pitting edema in his legs bilaterally. Left ventricular ejection fraction (LVEF) is measured by echocardiogram and found to be 36%. This is decreased from his last measurement of 41%. He is put on a second diuretic that is a channel blocker with an additional effect that corrects an electrolyte imbalance in this patient. Which of the following medications is consistent with this description?