I've Been Taking Amlodipine Along With Metoprolol Succ At 50

I've been taking amlodipine along with Metoprolol Succ at 50 Mg. for a few years now. Lately, I've experienced very tired feelings along with rapid heartbeat after taking them together. Today, I took the Metoprolol by itself and experienced a reduced amount of the side-effects described. It appears that taking these two drugs together are beginning to produce pronounced side-effects that I've not noticed before.