Yes. I recently took Zyrtec with Zantac for the first time and had horrible tachycardia for 4 days. But I should also mention that I simultaneously had food poisoning begin the same day after having been at a Christmas Pot Luck. I had just started my gluten free diet. Four others got food poisoning also, but no one was hit nearly as hard as I was and no one else had a racing heart, but me. I have been trying to work up the courage to try this drug combo again.