Hi, Since any HRT is associated with side effects and long term monitoring, you may give the prescribed drug a trial of at least a month before you switch over to another preparation after discussing with your doctor. Since the basic drug in the two preparations is different, you could be experiencing the change. Use of Premarin for a prolonged period is associated with several complications and as such, it may be withheld for a while. Please try to use natural remedial measures like use of loose-fitting cotton clothing, keeping your surroundings cool, practicing breathing exercises everyday at specific intervals, avoidance of stress, alcohol, smoking and beverages like coffee. Hope this helps.