A 72-year-old woman suffers from diabetes mellitus type 2, concomitant diseases are stage 2 hypertension and stage 2B heart failure. She takes metformin. Hypertensic crisis had occurred the day before, after which the patient developed extreme weakness, myalgias, thirst, dry mouth, polyuria. BP is 140/95 mm Hg, heart rate is 98/min., no edemas or smell of acetone detected. What measures should be taken to prevent development of comatose state in the patient?