please guide me
my friend is 65 years old , and he is using several years Nitrocontin 2.6 with Deltiazem 120 and Atorvastatin

but one of the doctor told for better control blood pressure and heart , add Metoprolol
But Another Doctor told Add Amlodipine
now i have question is there any side effect if he add Metoprolol or Amlodipine to ( Nitrocontin 2.6 with Deltiazem ) ?

may friend want to know which one is better to add , want to know Metoprolol or Amlodipine ?

i hope you guide me
and sorry for my english and if it's possible please guide e easy
thank you