DextromethorphanDextrorphanCoughAntitussive AgentsLevorphanolAsthmaCytochrome P-450 CYP2D6Oxidoreductases, O-DemethylatingCold TemperatureQuinidineGuaifenesinCodeineWhooping CoughChlorpheniraminePerhexilineCytochrome P-450 Enzyme SystemDebrisoquinGastric DilatationCommon ColdExpectorantsMorphinansExcitatory Amino Acid AntagonistsPseudobulbar PalsyAnti-Asthmatic AgentsReceptors, sigmaNasal DecongestantsMemantineMicrosomes, LiverReceptors, N-Methyl-D-AspartateDealkylationDouble-Blind Method