DextromethorphanNasal DecongestantsNasal ObstructionDextrorphanCoughAntitussive AgentsSneezingRhinitis, Allergic, PerennialLevorphanolNasal Provocation TestsNasal MucosaRhinitis, Allergic, SeasonalRhinitisAmbrosiaHistamine H1 Antagonists, Non-SedatingCytochrome P-450 CYP2D6Anti-Allergic AgentsLoratadineEphedrineOxidoreductases, O-DemethylatingCold TemperatureToluene 2,4-DiisocyanateAirway ResistanceQuinidineAdministration, IntranasalGuaifenesinDouble-Blind MethodCodeineNasal PolypsWhooping CoughChlorpheniramineNasal SeptumPerhexilineCytochrome P-450 Enzyme SystemDebrisoquinGastric DilatationCommon ColdExpectorantsMorphinansExcitatory Amino Acid AntagonistsPseudobulbar PalsyNasal Lavage FluidReceptors, sigmaMemantineMicrosomes, LiverNoseReceptors, N-Methyl-D-AspartateDealkylation