Hi, I have a friend that is eighty years old and he is on heart medications: Lipitor 40 mg, Cardizem 180 mg, Metroprolol Succinate 100 mg, Valasarttan 160 mg. He has been experiencing some arthritis pain, and a friend told him about taking Cannabidiol for his pain. He bought a small dropper bottle of the CBD oil at a health food store and has taken 10 drops of the tincture. Is this CBD oil dangerous for him to take for his pain?