I am on the 20mg mentioned above & 5mg amlodipine but my BP remains consistently in the low 140's to upper 130's... i've been on this treatment for over 6 mos... can i do away with the 5mg & double the lisinopril without causing harm to myself? Can I double my dose of 20 mg lisinopril/hydrochlothorazide if my BP remains in the low 140's?