Overall it is effective. I am starting to have hand tremors & anxiety. Probable side effects.

I feel very anxious and shaky.

Took it for several months with no positive effect so was taken off and ablation was attempted but unsuccessful. Had several VTach episodes of 8 ectopics in a row for 15 mins. Was hospitalized and put back on Tambocor. Started on 50mg twice daily. Still had 9.5% of beats being ectopic. Increased dose to 200mg a day and after a full month on increased dose have had 3 decent days with minimal PVCs. Am also taking verapamil 240mg daily.

26 years ive been on, longest person in world to take it Ive been told. Never had any problems few slight side affect dizziness, fatique no long term major issues to this point . Went from 400 mg after 23 years to 200 to 100 to 50 to nothing in the last year and as of last 5 days nothing and my issue seems to be gone so I think God has cured me of whatever it was but for 26 years nobody would try reducing it they said it works leave it alone . All though i know the side affects of having a heart attach seem to be a bad deal possibly. especially at 400 mg which i was one thats a heavy dose.

This medicine has been ok for me I do get tired taking it but all in all no problems

I was diagnoised with a high heart rate in 1992 and started on Tenormin, it worked great by itself until late 1994. Have been on several meds and had an EP study with radial ablation that was unsucessful, with tachycardia that never slowed down after the procedure. In fact, it was so bad that I had to start Tambocor before my heart was healed from the surgery. Have been on Tambocor ever since 1995 and am very exhaused all the time but I also have chronic fatigue syndrome. I still have tachycardia but usually only last a few minutes. I would probably have died had I not gotten on Tambocor.