atrial flutte
"I had a terrible reaction to Cartia XT's formulation of Cardizem, when my usual manufacturer, PAR who also makes Cardizem capsules, was not in stock at my pharmacy.
So they substituted Cartia XT's formulation of Cardizem; I began having extreme racing, more than usual AF, and it continued to recur within about an hour after taking it each day.  
It was very alarming, because PAR manufacturer of Cardizem never gave me a bad reaction and I had been taking it for years.
Pharmacists who try to tell you that all generics are the same but that is misleading.  the main ingredient prescription drug must be the same as the brand; but the manufacturer can vary the remaining ingredients; and it is very difficult to find out what they are."