Patent ID: 8688385

Claim:
A method of administering an initial dose of a psychotropic medication to a patient in need thereof, the initial dose based upon an initial dose recommended in the clinical guidelines for the psychotropic medication, the method comprising: (1) determining the patient's genotype for a panel of cytochrome P450 CYP2D6 alleles selected from the following alleles: (a) fully functional alleles *1A, *2A, *2N, and *35, (b) partially functional alleles *2BD, *9, *10, *12,*17, *41, and (c) non-functional alleles *3, *4, *5, *6, *7, *8, and *11, (2) assigning a metabolic phenotype to the patient based on the genotype of the cytochrome P450 genes in (1), wherein the metabolic phenotype is selected from poor (P), intermediate (I), and extensive (E), and said phenotype is assigned based upon the number of functional alleles for each cytochrome P450 gene as follows: P=no fully functional alleles and either one or no partially functional alleles, I=either one fully functional allele and a non-functional allele or two partially functional alleles, and E=either one fully functional allele and one partially functional allele or two fully functional alleles; and (3) administering to the patient an initial dose of the psychotropic medication selected from the group consisting of (a) an initial dose that is half the initial dose recommended in the clinical guidelines if the patient has been assigned a poor (P) metabolic phenotype in step 2; and (b) an initial dose that is the same as the initial dose recommended in the clinical guidelines if the patient has been assigned an intermediate (I) metabolic phenotype in step 2, provided that the patient is a non-geriatric patient; and wherein the psychotropic medication is selected from the group consisting of amitriptyline, fluoxetine, imipramine, nortriptyline, paroxetine, and venlafaxine.