Can i smoke medical marijuana while taking amlodipine?

There are no known drug interactions but marijuana is known to affect the heart. It can raise blood pressure and cause cardiac arrhythmia.

Mostly, yes. Cannabis has slight increases in pulse and blood pressure but not in ways that directly interact with amlodipine and they are small. Some people MIGHT have consequences of cannabis effect on the BP, but since it is about like walking up a flight of stairs, these people would have a lot of problems in that regard.