Cardizem LASide Effects - XML FEED - Medications.com http://www.medications.com/se/Cardizem+LA Recent side effects for Cardizem LA Taking it for several years. Most recent blood test showed very Tue, 22 Apr 2008 09:27:06 -0400 http://www.medications.com/effect/view/29824 Taking it for several years. Most recent blood test showed very high potassium levels, causing doctor to have great concern. Looking on the internet I found that Cardizem LA can cause high potassium levels. http://www.medications.com/effect/view/29824