I wrestled with the FAA on my 2nd class medical due to tachycardia caused by antihistamines. Thank you, Zyrtec. I had to jump through all kinds of hoops, even though the report from the cardiologist stated that I was a "profoundly boring patient" as it relates to heart issues and confirmed that the temporary issue was medication related. The FAA still required a multitude of tests. I went back to Basic Med the day I received my SI.