I am not a doctor but as I understand it, 25 mg a day is considered a 'low' dose, and 12.5 mg a day is considered a 'very low' dose, so it seems you're in the low dose range. doses above 25 mg a day do not lower blood pressure any more than the low dose regimen and in fact may screw up the lipid and glucose profile. if your doc wants to up the dosage any more, I'd be suspect.