This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
A 45-year-old man has hypeension. A thiazide diuretic agent had been prescribed with continued elevated blood pressure. The inclusion of spironolactone to the thiazide diuretic is done to achieve wof 
Select and explain. 
A. Reduce hyperuricemia, B. Reduce Mg + loss, C. Reduce K + loss, D. Decrease the loss of Na +
C: Reduce K + loss
Answer: C: Reduce K + loss 
Explanation: Potassium sparing diuretics Spironolactone,eplerenone and amiloride but not triamterene themselves lower BP slightly. However, they are used only in conjunction with a thiazide diuretic to prevent K+ loss and to augment the anti- hypeensive action. Spironolactone side effects Include gynaecomastia, impotence, menstrual irregularities. This problem has been offset in the newer aldosterone antagonist eplerenone. Ref:- kd tripathi; pg num:-561