I was on Irbesartan - HCTZ 150-12.5 ( avalide) for 2 weeks and BP bottom number was still up so Doctor change it to 300-12.5 on 9/6/2012. How long will it take to bring it down, I go back to doctor in 4 weeks. I was on Benicar for 4 yrs and changed Insurance and my new insurance will not pay for Benicar. Did any one else get a minor headache after starting Avalide and how long does it take for the body to adjust to the change