DextromethorphanDextrorphanCoughAntitussive AgentsLevorphanolCytochrome P-450 CYP2D6Oxidoreductases, O-DemethylatingQuinidineGuaifenesinCodeineWhooping CoughChlorpheniraminePerhexilineCytochrome P-450 Enzyme SystemDebrisoquinGastric DilatationMorphinansExcitatory Amino Acid AntagonistsPseudobulbar PalsyExpectorantsReceptors, sigmaMemantineMicrosomes, LiverNasal DecongestantsReceptors, N-Methyl-D-AspartateDealkylation