Histamine H1 AntagonistsReceptors, Histamine H1Receptors, Histamine H3HistamineReceptors, Histamine H2Histamine AntagonistsHistamine H1 Antagonists, Non-SedatingHistamine AgonistsHistamine H2 AntagonistsReceptors, HistamineChlorpheniramineHistamine H3 AntagonistsCetirizineLoratadineHistamine ReleaseTerfenadineDiphenhydramineMethylhistaminesAstemizoleUrticariaTriprolidineAnti-Allergic AgentsDibenzoxepinsButyrophenonesDoxepinCimetidineDimapritPyrilamineCyproheptadineMetiamidePruritusKetotifenRhinitis, Allergic, PerennialPromethazinePiperidinesThioureaSneezingClemastineHistamine N-MethyltransferaseImpromidineGuinea PigsRhinitis, Allergic, SeasonalFamotidineHistamine AgentsRanitidineAnaphylaxisBurimamideHistidine DecarboxylaseDose-Response Relationship, DrugHydroxyzinePheniramineDibenzazepinesIsothiuroniumChenopodium albumHypersensitivityMast CellsDimethindenePhenothiazinesNasal DecongestantsDrug HypersensitivityTripelennamineBrompheniramineCyclizineRadioligand Assayp-Methoxy-N-methylphenethylamineTrimeprazineToluene 2,4-DiisocyanateGastric AcidReceptors, G-Protein-CoupledLeukotriene AntagonistsCromolyn SodiumConjunctivitis, AllergicAngioedemaImidazolesHormone AntagonistsAntipruriticsConjunctivitisNeurokinin-1 Receptor AntagonistsDopamine AntagonistsRats, WistarRats, Sprague-DawleyExcitatory Amino Acid AntagonistsNasal ObstructionAdministration, OralBetahistinePyridinesPrurigoPiperazinesDrug InteractionsDouble-Blind MethodGuanidinesNarcotic AntagonistsBenzimidazolesAdrenal Cortex HormonesGastric MucosaBinding, CompetitiveMuscle, SmoothInterleukin 1 Receptor Antagonist ProteinPyrrolidinesTime Factors