tokens: The serum K during the control period was 4 . 5 + / - 0 . 2 mEq / l an on 50 , 100 , 150 and 200 mg HCTZ daily 3 . 9 + / - 0 . 3 , 3 . 4 + / - 0 . 2 , 2 . 9 + / - 0 . 2 , and 2 . 4 + / - 0 . 3 mEq / l , respectively .