Our 12 Yo Lab/border Collie Mix Has Been On Pro

Our 12 yo Lab/border collie mix has been on pro pectalin tablets for last 2-3 weeks, secondary to colitis with vomiting and bloody diarrhea, other meds were flagyl, ondancetron, and loperamide, he was on Novox prior to this colitis episode in the last couple of years. He is only on EN dry food with no meds at present time, but with loss of energy currently , probably secondary to loss of weight. Could the above meds cause any irregular heart rate? Or secondary problems? Any info would be greatly appreciated. Thank you