I have been on metoprolol for about two years 25mg for most of the time. I was recently upped to 75mg now have tinnitus. Load buzzing humming sound. Is this a side effect of Metoprolol? I asked my Cardiologist nurse practitioner she says no but I found evidence it can. Anyone else experience this? I was put on this to bring my heart rate down diagnosed with sinus tachycardia.