Zyrtec/cetirizine is a weird one. Everyone seems to agree that it is a second-generation antihistamine. The FDA seems to play along. But there is no particular shortage of anecdotal evidence of people who find it quite sedating (hi there!), there are some papers questioning its status [0], and the FAA puts it in a category with diphenhydramine, not with loratadine and fexofenadine [1].

[0] https://pmc.ncbi.nlm.nih.gov/articles/PMC1118461/

[1] https://www.faa.gov/ame_guide/media/AllergyAntihistamineImmu...