348 F.C.W. Van Nieuwerburgh et al. [5] Tournel G, Houdret N, Hedouin V, Deveaux M, Gosset D, Lhermitte M. High-performance liquid chromatographic method to screen and quantitate seven selective serotonin reuptake inhibitors in human serum. J Chromatogr B Anal Technol Biomed Life Sci 2001;/761(2):/147 58. [6] Marez D, Legrand M, Sabbagh N, LoGuidice JM, Spire C, Laﬁtte JJ, et al. Polymorphism of the cytochrome p450 cyp2d6 gene in a european population: Characterization of 48 mutations and 53 alleles, their frequencies and evolution. Pharmacogenetics 1997;/7(3):/193 202. [7] Johansson I, Oscarson M, Yue QY, Bertilsson L, Sjoqvist F, Ingelmansundberg M. Genetic-analysis of the chinese cytochrome p4502d locus characterization of variant cyp2d6 genes present in subjects with diminished capacity for debrisoquine hydroxylation. Mol Pharmacol 1994;/46(3):/ 452 9. [8] Raimundo S, Toscano C, Klein K, Fischer J, Griese EU, Eichelbaum M, et al. A novel intronic mutation, 2988g a, with high predictivity for impaired function of cytochrome p450 2d6 in white subjects. Clin Pharmacol Ther 2004;/ 76(2):/128 38. [9] Solus JF, Arietta BJ, Harris JR, Sexton DP, Steward JQ, McMunn C, et al. Genetic variation in eleven phase i drug metabolism genes in an ethnically diverse population. Pharmacogenomics 2004;/5(7):/895 931. [10] Bradford LD. Cyp2d6 allele frequency in european cauca- sians, asians, africans and their descendants. Pharmacoge- nomics 2002;/3(2):/229 43. [11] Koran LM, Hanna GL, Hollander E, Nestadt G, Simpson HB. Practice guideline for the treatment of patients with obsessive-compulsive disorder. Am J Psychiatry 2007;/ 164(Suppl 7):/5 53. [12] Denys D, van der Wee N, van Megen HJGM, Westenberg HGM. A double blind comparison of venlafaxine and paroxetine in obsessive-compulsive disorder. J Clin Psycho- pharmacol 2003;/23(6):/568 75. [13] Hollander E, Allen A, Steiner M, Wheadon DE, Oakes R, Burnham DB, et al. Acute and long-term treatment and prevention of relapse of obsessive-compulsive disorder with paroxetine. J Clin Psychiatry 2003;/64(9):/1113 21. [14] YaryuraTobias JA, Neziroglu FA. Venlafaxine in obsessive- compulsive disorder. Arch Gen Psychiatry 1996;/53(7):/ 653 4.