Which is stronger allegra ,zyrtec or claritin (loratadine) i know they all treat same thing which one more likely to be strongest?

All r created equal: But one might be more equal (convenient) to a patient than another, as different patients respond differently to different drugs, that's what they call: pharmacogenetics, a relatively new science that can tell how patients would respond to different drugs, bit expensive though to be tried on every medicine, so trial and error would be the way to go for now, good luck