The antihistamine claritin contains loratadine. Loratadine is a long-acting antihistamine having the empirical formula C₂₂H₂₃ClN₂O₂ and the chemical name ethyl 4-(8-chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b] pyridin-11-ylidene)-1-piperidinecarboxylate.