A 50-year-old man presents for follow-up of his hypertension. He is main- taining a low-sodium diet, exercising regularly, and taking metoprolol at max- imum dosage. He is on no other medications. His blood pressure remains elevated at 150/100 mm Hg. His examination is otherwise unremarkable. You decide to add a thiazide diuretic to his regimen.
1) What is the mechanism of action of metoprolol?
2) What is the mechanism of action of thiazide diuretics?
3) What electrolyte abnormalities commonly occur with thiazide diuretics?