I take lopressor for sinus tachycardia. Initially, I was put on a very high dosage and could not tolerate it. I've had to cut it twice now, doing so 25 mg at a time. Each time I cut it, I experienced similar symptoms as you. If you are on a beta blocker for a long enough time, you may experience withdrawal effects for a few days after reducing the dose. That happened to me each time, but it cleared up within 5-7 days. Good luck.
I was on a low dose of metoprolol for about a month. It slowed my hearbeat down to the 40's (I have bradycardia anyhow), which is too slow. I dropped it cold turkey, having been told by my cardiologist at Mayo Clinic that I could do that with no adverse effects. He was right: no bad effects. I feel fine. Maybe your problems are due to something else???
Sorry, I meant to say I have taken 150mg of Lopressor for 6 years now without any adverse side effects.
I was able to stop taking Amiodarone cold turkey after 9 months of use with no problems. I was already on the Lopressor for my blood pressure when I developed SVTs. After reading up on the Amiodarone and having to be monitored while taking that drug, I decided I didn't want to take it anymore. I told my doctor about my decision, but stopped abruptly. The SVT symptoms had diminished at that time any way. My symptoms have never returned so far. If you are experiencing those symptoms again, I would ressume the metoprolol and discuss this with your doctor again. Sometimes it takes some trial and error before we can get it all right. My heart spasms took some time to get better, and I had to try a few meds before I got it right. I have taken 150mg daily of this drug without any adverse reactions for 6 years now. Take care, Ally