@normanchester I can well understand the feeling of anxiety you might get from "cold-turkeying" off your metoprolol. This drug is a beta-blocker which acts to competitively inhibit the "fight or flight" hormones adrenaline and no-adrenaline from attaching to the "beta-receptors" in your heart (and other organs, depending on which beta-blocker drug it is, metoprolol is a more cardiac-specific beta blocker than some of the others) and allowing the hormones to act. This drug acts to slow the heart rate, reduce the force of contractions and lowers the blood pressure by it's inhibition of those hormones.

If a person has taken this drug for some time, stopping it cold turkey can cause a rebound effect, as those beta receptors are no longer blocked by the drug, and the person may have even grown more beta receptors in response to the drug's action ( depending on the dose and length of time taken). I've experienced this rebound as jitteriness, an increased heart rate in response to very little stimuli, and I could say at least a little anxiety. That's the reason the drug manufacturers, prescribing healthcare providers strongly recommend tapering off the drug when the plan is to stop it.

The details of tapering down the drug depend on the dosage the person is taking. I've been told that it may not be necessary to taper off a low dosage of the metoprolol, ie, 25 mg/day. I had to stop the metoprolol I was taking a number of years ago, and the electrophysiologist I was working with said I definitely had to taper off at the dose I was taking ( 150mg/day). His instructions were to taper it off over a two week period, ie, cut down to 100 mg/day the first week, then 50 mg/day the second week, then stop taking any after that. I had to switch over to diltiazem ER after that, but I still felt the jitters and heart rate increases even with the tapering of the metoprolol, and the diltiazem was pathetically ineffective for the issues I had.