<prompt> Translate the following text to EnglishHakuna mojawapo ya dawa tatu kuu za antihistamines Allegra, Claritin, Zyrtec inayoonekana kuwa yenye matokeo zaidi kuliko nyingine.  <response>: None of the three major prescription antihistamines Allegra, Claritin, Zyrtec seems to be consistently more effective than the others. 