Kuo H.-W.Liu S.C.Tsou H.-H.Liu S.-W.Lin K.-M.SHAO-CHUN LUHsiao M.-C.Hsiao C.-F.Liu C.-Y.Chen C.-H.Lu M.-L.Shen W.W.Tang H.-S.Liu S.-I.Chang L.-H.Wu H.-Y.Chang Y.-S.Yeh T.-K.Chen A.C.Liu Y.-L.2020-02-062020-02-0620131462-2416https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880485709&doi=10.2217%2fpgs.13.105&partnerID=40&md5=b63d94269f2ab871d1790a54ffc33230https://scholars.lib.ntu.edu.tw/handle/123456789/454616Aim: The liver CYP1A2 enzyme may metabolize antidepressant escitalopram (S-CIT) to S-desmethylcitalopram (S-DCIT) and S-didesmethylcitalopram (S-DDCIT). This study tested whether genetic polymorphisms in the CYP1A2 gene are associated with the treatment responses to S-CIT. Materials & methods: Ten SNPs in CYP1A2 were selected and genotyped in 158 patients under S-CIT treatment. The serum levels of S-CIT and its metabolites were measured by HPLC. Results:CYP1A2 SNPs rs2069521, rs2069526, rs4646425 and rs4646427 are significantly associated with the metabolic ratios of S-DDCIT/S-DCIT (p = 0.002, 0.018, 0.008 and 0.004, respectively) at week 2 of treatment. Carriers of the allele types associated with higher S-DDCIT/S-DCIT ratios had more severe side effects. Conclusion: These results suggest that genetic variants in CYP1A2 may be indicators for S-CIT metabolism and that the fast metabolizers may experience more severe adverse reactions in the early stages of S-CIT treatment. Original submitted 27 December 2012; Revision submitted 15 May 201. ? 2013 Future Medicine Ltd.CYP1A2; escitalopram; major depressive disorder; side effects; SNP[SDGs]SDG3cytochrome P450 1A2; dinorcitalopram; drug metabolite; escitalopram; norcitalopram; unclassified drug; antidepressant agent; citalopram; cytochrome P450 1A2; adverse outcome; allele; article; Clinical Global Impression scale; cohort analysis; controlled study; CYP1A2 gene; disease severity; drug blood level; drug metabolism; drug response; drug safety; fatigue; female; gene locus; genetic association; genetic variability; genotype; Hamilton scale; haplotype; heterozygote; high performance liquid chromatography; human; major clinical study; major depression; male; nausea; patient compliance; single nucleotide polymorphism; smoking; vomiting; xerostomia; adverse drug reaction; Depressive Disorder, Major; gene linkage disequilibrium; genetic polymorphism; genetics; middle aged; pathology; single nucleotide polymorphism; Antidepressive Agents; Citalopram; Cytochrome P-450 CYP1A2; Depressive Disorder, Major; Drug-Related Side Effects and Adverse Reactions; Female; Genetic Association Studies; Haplotypes; Humans; Linkage Disequilibrium; Male; Middle Aged; Polymorphism, Genetic; Polymorphism, Single Nucleotidejournal article10.2217/pgs.13.1052-s2.0-84880485709