Hi My K Is 5.9 It Was 5.4 For The

Hi my K is 5.9 it was 5.4 for the past year. I am a diabetic type 2 and have been on 20 mg Lisinopril and 80mg of Verapamil ER BID. I am very concerned of why my K is so high. I also have A-Fib which is under control at this time. I am suppose to take Kionex one time dose tonight but, I have a concern with the side affects which include heart rhythm problems. I have been sitting here for the past hour just holding this bottle. I know this will bring down my K but I need to know why it is up in the first place.