Has anyone ever developed side effects from a medication they've been on for a long time? I've been on the lowest dose of metoprolol tartrate (25 mg BID) for years, but in the last few months I've been getting unsteady on my feet, dizziness upon standing and actually have to hold onto things to walk or stand in one place. This always happens 2 to 4 hours after taking a dose and mostly disappears when I wake up in the morning. I take my morning dose at 7:30 and by 10 or so it's back. As I said I've been on it for over 2 years and this started a couple of months ago, also bring on the lowest dose I don't know if it has anything to do with it but the timing is the same every day. Oh yeah, it happens when I stand but my pulse doesn't race or anything.