Hi, Thanks for using Healthcaremagic, You are suffering from High blood pressure and congestive heart failure. The drug is Metolazone which is diuretic (Water pill) used for oedema causes dehydration and electrolyte loss both sodium and potassium which is possible reason of weakness and fatigue. This is good drug effective even when other classes of diuretics are not effective. Treatment of congestive heart failure needs salt restriction fluid restriction, and other cardiac drugs, like ACE inhibitors and beta blockers. You can always take second opinion, keep blood pressure to optimum level, You can check Kidney function and electrolytes to know everything is fine. In treatment option if rhythm changes are detected resynchronization device may be useful. Hope this information is useful to you. Take care. Good Luck. Dr.Akhilesh Dubey M.D.