We have a great heart rhythm forum here and I would read what they have to say, there are many knowledgable folks there. I will say one thing, if you have had a complete cardiac work up and all is fine, then I would not worry about the PVC's, if your heart is healthy, they will not harm you at all.
I hope you have called your doctor about this however, since this started after taking the med, he needs to know this and he can act accordingly. I would get in to see him as soon as you can. How are you doing today?
I would call your doctor. A forum is not appropriate for an emergency.