Abstract
Aims and Objective: The plasma level of mirtazapine (MIR) varies between individuals
primarily depending on the differences in metabolism during pharmacotherapy. CYP2D6 takes the role
as a major enzyme in MIR metabolism and POR enzyme donates an electron to CYP2D6 for its activity.
Single nucleotide polymorphisms in the genes encoding pharmacokinetic enzymes may cause changes in
enzyme activity, leading to differences in metabolism of the drug. Our aim was to assess the influence of
CYP2D6*4 and POR*28 polymorphisms on MIR plasma levels in Turkish psychiatric patients.
Materials and Methods: The association between genetic variations and plasma level of MIR was
investigated on 54 patients. CYP2D6*4 and POR*28 polymorphisms were analysed using
Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) and plasma
MIR levels were measured using HPLC.
Results: Allele frequencies of CYP2D6*4 and POR*28 were 0.11 and 0.39, respectively in the
study population. The results showed that CYP2D6*4 allele carriers have higher C/D MIR levels
while POR*28 allele carriers have lower C/D MIR levels. Combined genotype analyses also
revealed that individuals with CYP2D6*1/*1 - POR*28/*28 genotype have a statistically lower
C/D MIR level (0.95 ng/ml/dose) when compared with individuals with CYP2D6*1/*1 -
POR*1/*1 genotype (1.52 ng/ml/dose).
Conclusion: Our results indicate that CYP2D6*4 and POR*28 polymorphisms may have a
potential in the explanation of differences in plasma levels in MIR treated psychiatric patients. A
combination of these variations may be beneficial in increasing drug response and decreasing
adverse drug reactions in MIR psychopharmacotherapy.
Keywords:
Mirtazapine, CYP2D6*4, POR*28, plasma, HPLC, MIR psychopharmacotherapy.
[1]
GBD 2015 Disease and injury incidence and prevalence collaborators. global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the global burden of disease study 2015. Lancet, 2016, 388(10053), 1789-1858.
[3]
Hiemke, C.; Bergemann, N.; Clement, H.W.; Conca, A.; Deckert, J.; Domschke, K.; Eckermann, G.; Egberts, K.; Gerlach, M.; Greiner, C.; Gründer, G.; Haen, E.; Havemann-Reinecke, U.; Hefner, G.; Helmer, R.; Janssen, G.; Jaquenoud, E.; Laux, G.; Messer, T.; Mössner, R.; Müller, M.J.; Paulzen, M.; Pfuhlmann, B.; Riederer, P.; Saria, A.; Schoppek, B.; Schoretsanitis, G.; Schwarz, M.; Gracia, M.S.; Stegmann, B.; Steimer, W.; Stingl, J.C.; Uhr, M.; Ulrich, S.; Unterecker, S.; Waschgler, R.; Zernig, G.; Zurek, G.; Baumann, P. Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology: Update 2017. Pharmacopsychiatry 2018, 51(1-02), 9-62.
[10]
Leonard, S.D.; Karlamangla, A. Dose-dependent sedating and stimulating effects of mirtazapine. Proc UCLA Healthc, 2015, pp. 1-2.
[21]
Langman, L.; van Gelder, T.; van Schaik, R.N.H. Pharmacogenetics Aspects of Immunosuppressant Threapy.In: Personalized Immunosuppression in Transplantation Role of Biomarker Monitoring and Therapeutic Drug Monitoring; Oellerich, M.; Dasgupta, A., Eds.; Elsevier, 2016, pp. 109-124.
[23]
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th ed; , 2013.
[27]
Dural, E.; Baskak, N.S.; Ozcan, H.; Kır, Y.; Baskak, B.; Suzen, H.S. Determination of mirtazapine and desmethyl mirtazapine in human plasma by a new validated HPLC ultraviolet method with a simple and reliable extraction method: Application to therapeutic drug monitoring study by 62 real patient plasma. Iran. J. Pharm., 2020, 19(1), 18-30.