Anyone, is it ok to change one med to another

[worried784]

back to back?  I have been taking a calcium channel blocker-diltyeizem for my tachycardia and high blood pressure and it is not really lowering either.  My tachycardia is sometimes 150/60 and I am suppossed to start taking a beta blocker-nadolol 40 mg. My question is: wouldn't the CCB still be in my system while starting the beta blocker?  I have been on it over 2 months and will start the beta blocker tomorrow. What can I expect, is that safe? Thanks to anyone who can advise. My heart rate is so rapid and I feel awful.  I already tried a beta blocker-metaprolol before the CCB and didn't feel too great then either. I'm told these are the only 2 meds for inappropriate sinus tachycardia, which is what it is (supossed) to treat, even though it also (should) work for high blood presure.  Thank you so much, sorry for some words spelled incorrectly, but I'm so nervous (suffer from anxiety too) and I hoped to get some feedback before I start on the beta blocker.
Thanks,
hopingforslowerheartrate (worried784)

[worried784]

Thanks so much, and you are absolutely right about my anxiety.  He wanted to put me on an anti-depressent/anxiety med because he knows (as I do) that my anxiety contributes to my inappropriate sinus tachycardia and high blood pressure.  I actually think it caused it, but have had it for so many years, and am used to it, but it's life altering.  Brooke, you have answered me before and I thank you.

[Brooke_38]

oops I didn't finish my thought up there ;) anxiety will cause your BP&heart rate to increase.

Hope this helps you feel less anxious about taking the Nadalol.

[Brooke_38]

OK...first take a deep breath and try to relax. I know it's easier said than done. Your anxiety will only raise you BP and heart rate.

At one time I was on 360mg Diltiazem 1xday and 40mg Nadalol 2xday. So I'm sure you will be fine.  

As for treating IST...These meds are not the only 2 that are used. Actually, they try treating with SSRI's like Paxil etc.