Effect of Polymorphisms on the Pharmacokinetics, Pharmacodynamics and Safety of Sertraline in Healthy Volunteers

Machine Learning-Based Prediction of Escitalopram and Sertraline Side Effects With Pharmacokinetic Data in Children and Adolescents

Selective serotonin reuptake inhibitors (SSRI) are the first-line pharmacologic treatment for anxiety and depressive disorders in children and adolescents. Many patients experience side effects that are difficult to predict, are associated with significant morbidity, and can lead to treatment discontinuation. Variation in SSRI pharmacokinetics could explain differences in treatment outcomes, but this is often overlooked as a contributing factor to SSRI tolerability. This study evaluated data from 288 escitalopram-treated and 255 sertraline-treated patients ≤ 18 years old to develop machine learning models to predict side effects using electronic health record data and Bayesian estimated pharmacokinetic parameters. Trained on a combined cohort of escitalopram- and sertraline-treated patients, a penalized logistic regression model achieved an area under the receiver operating characteristic curve (AUROC) of 0.77 (95% confidence interval (CI): 0.66-0.88), with 0.69 sensitivity (95% CI: 0.54-0.86), and 0.82 specificity (95% CI: 0.72-0.87). Medication exposure, clearance, and time since the last dose increase were among the top features. Individual escitalopram and sertraline models yielded an AUROC of 0.73 (95% CI: 0.65-0.81) and 0.64 (95% CI: 0.55-0.73), respectively. Post hoc analysis showed sertraline-treated patients with activation side effects had slower clearance (P = 0.01), which attenuated after accounting for age (P = 0.055). These findings raise the possibility that a machine learning approach leveraging pharmacokinetic data can predict escitalopram- and sertraline-related side effects. Clinicians may consider differences in medication pharmacokinetics, especially during dose titration and as opposed to relying on dose, when managing side effects. With further validation, application of this model to predict side effects may enhance SSRI precision dosing strategies in youth.

Investigation into the impact of proton pump inhibitors on sertraline transport across the blood-brain barrier

As a widely used antidepressant that works by inhibiting the reuptake of serotonin, sertraline exerts an antidepressant effect depending on its concentration in the brain, which might be limited by the blood-brain barrier (BBB). It is highly possible to combine proton pump inhibitors (PPIs) with sertraline in clinical trials. Nevertheless, the role played by PPIs in regulating the transport of sertraline across the BBB remains unclear. Here, the impact of PPIs on the distribution of sertraline in the brain and the mechanisms involved were investigated. A mouse brain distribution study showed that Omeprazole (OME), Pantoprazole (PAN), Ilaprazole (ILA), and Esomeprazole (ESO) increased the area under the brain concentration-time curves (AUC) for sertraline by 2.02-, 3.18-, 3.04-, and 4.21-fold, respectively, after the 14-day administration of PPIs. Besides, PPIs significantly increased the permeability of sertraline in brain perfusion experiments, with PAN having the highest rank order, followed by ILA, OME, and ESO. In the tail suspension test (TST), co-administration PPI groups showed significantly shorter immobility time than the control group. In vitro, four PPIs inhibited sertraline efflux in breast cancer resistance protein (BCRP)-overexpressing MDCKII cells, and showed a mixed inhibition type. In this study, PPIs were further found to inhibit the mRNA and protein expression of brain BCRP. To sum up, the findings of this study revealed that PPIs could enhance the brain distribution and antidepressant effect of sertraline, which may be attributed to the inhibition of BCRP expression at the BBB by PPIs.

Population pharmacokinetic approach to guide personalized sertraline treatment in Chinese patients

Object: Sertraline is a first-line SSRI for the treatment of depression and has the same effectiveness along with a superior safety profile compared to other medications. There are few population pharmacokinetic (PPK) studies of sertraline and a lack of studies in the Chinese population. Therefore, we performed a PPK analysis of Chinese patients treated with sertraline to identify factors that can influence drug exposure. In addition, the dosing and discontinuation regimen of sertraline when applied to adolescents was explored. Methods: Sertraline serum drug concentration data were collected from 140 hospitalized patients to generate a sertraline PPK dataset, and data evaluation and examination of the effects of covariates on drug exposure in the final model were performed using nonlinear mixed-effects models (NONMEM) and first-order conditional estimation with interaction (FOCE-I). Examining rational medication administration and rational withdrawal of sertraline based on significant covariates and final modeling. Results: A one-compartment model with first-order absorption and elimination of sertraline was developed for Chinese patients with psychiatric disorders. Analysis of covariates revealed that age was a covariate that significantly affected sertraline CL/F (P < 0.01) and that sertraline clearance decreased progressively with aging, whereas other factors had no effect on CL/F and V/F of sertraline. In the age range of 11-79, there were 54 adolescent patients (about 1/3) aged 13-18 years, and the safe and effective optimal daily dose for adolescent patients based on the final model simulations was 50-250 mg/d. For adolescent patients, serum concentration fluctuations were moderate for OD doses of 50 mg and 100 mg, using a fixed dose-descent regimen. For patients with OD doses of 150-200 mg and BID doses of 100-200 mg, a more gradual decrease in serum concentration was achieved with a fixed dose interval of 7 or 14 days for 25 mg as the regimen of descent. Conclusions: To our knowledge, this may be the first PPK study of sertraline in Chinese patients. We found that age was an important factor affecting clearance in Chinese patients taking sertraline. Patients taking sertraline may be exposed to increased amounts of sertraline due to decreased clearance with increasing age. The rational dosing and safe discontinuation of sertraline in adolescent patients can be appropriately referenced to the results of the model simulation, thus providing assistance for individualized dosing in adolescents.

Impact of CYP2C:TG Haplotype on CYP2C19 Substrates Clearance In Vivo, Protein Content, and In Vitro Activity

A novel haplotype composed of two non-coding variants, CYP2C18 NM_000772.3:c.*31T (rs2860840) and NM_000772.2:c.819+2182G (rs11188059), referred to as "CYP2C:TG," was recently associated with ultrarapid metabolism of various CYP2C19 substrates. As the underlying mechanism and clinical relevance of this effect remain uncertain, we analyzed existing in vivo and in vitro data to determine the magnitude of the CYP2C:TG haplotype effect. We assessed variability in pharmacokinetics of CYP2C19 substrates, including citalopram, sertraline, voriconazole, omeprazole, pantoprazole, and rabeprazole in 222 healthy volunteers receiving one of these six drugs. We also determined its impact on CYP2C8, CYP2C9, CYP2C18, and CYP2C19 protein abundance in 135 human liver tissue samples, and on CYP2C18/CYP2C19 activity in vitro using N-desmethyl atomoxetine formation. No effects were observed according to CYP2C:TG haplotype or to CYP2C19*1+TG alleles (i.e., CYP2C19 alleles containing the CYP2C:TG haplotype). In contrast, CYP2C19 intermediate (e.g., CYP2C19*1/*2) and poor metabolizers (e.g., CYP2C19*2/*2) showed significantly higher exposure in vivo, lower CYP2C19 protein abundance in human liver microsomes, and lower activity in vitro compared with normal, rapid (i.e., CYP2C19*1/*17), and ultrarapid metabolizers (i.e., CYP2C19*17/*17). Moreover, a tendency toward lower exposure was observed in ultrarapid metabolizers compared with rapid metabolizers and normal metabolizers. Furthermore, when the CYP2C19*17 allele was present, CYP2C18 protein abundance was increased suggesting that genetic variation in CYP2C19 may be relevant to the overall metabolism of certain drugs by regulating not only its expression levels, but also those of CYP2C18. Considering all available data, we conclude that there is insufficient evidence supporting clinical CYP2C:TG testing to inform drug therapy.

Escitalopram and Sertraline Population Pharmacokinetic Analysis in Pediatric Patients

BACKGROUND AND OBJECTIVE

Escitalopram and sertraline are commonly prescribed for anxiety and depressive disorders in children and adolescents. The pharmacokinetics (PK) of these medications have been evaluated in adults and demonstrate extensive variability, but studies in pediatric patients are limited. Therefore, we performed a population PK analysis for escitalopram and sertraline in children and adolescents to characterize the effects of demographic, clinical, and pharmacogenetic factors on drug exposure.

METHODS

A PK dataset was generated by extracting data from the electronic health record and opportunistic sampling of escitalopram- and sertraline-treated psychiatrically hospitalized pediatric patients aged 5-18 years. A population PK analysis of escitalopram and sertraline was performed using NONMEM. Concentration-time profiles were simulated using MwPharm++ to evaluate how covariates included in the final models influence medication exposure and compared to adult therapeutic reference ranges.

RESULTS

The final escitalopram cohort consisted of 315 samples from 288 patients, and the sertraline cohort consisted of 265 samples from 255 patients. A one-compartment model with a proportional residual error model best described the data for both medications. For escitalopram, CYP2C19 phenotype and concomitant CYP2C19 inhibitors affected apparent clearance (CL/F), and normalizing CL/F and apparent volume of distribution (V/F) to body surface area (BSA) improved estimations. The final escitalopram model estimated CL/F and V/F at 14.2 L/h/1.73 m2 and 428 L/1.73 m2, respectively. For sertraline, CYP2C19 phenotype and concomitant CYP2C19 inhibitors influenced CL/F, and empirical allometric scaling of patient body weight on CL/F and V/F was significant. The final sertraline model estimated CL/F and V/F at 124 L/h/70 kg and 4320 L/70 kg, respectively. Normalized trough concentrations (Ctrough) for CYP2C19 poor metabolizers taking escitalopram were 3.98-fold higher compared to normal metabolizers (151.1 ng/mL vs 38.0 ng/mL, p < 0.0001), and normalized Ctrough for CYP2C19 poor metabolizers taking sertraline were 3.23-fold higher compared to normal, rapid, and ultrarapid metabolizers combined (121.7 ng/mL vs 37.68 ng/mL, p < 0.0001). Escitalopram- and sertraline-treated poor metabolizers may benefit from a dose reduction of 50-75% and 25-50%, respectively, to normalize exposure to other phenotypes.

CONCLUSION

To our knowledge, this is the largest population PK analysis of escitalopram and sertraline in pediatric patients. Significant PK variability for both medications was observed and was largely explained by CYP2C19 phenotype. Slower CYP2C19 metabolizers taking escitalopram or sertraline may benefit from dose reductions given increased exposure.

Pharmacogenomics in allogeneic hematopoietic stem cell transplantation: Implications on supportive therapies and conditioning regimens

Allogeneic hematopoietic stem cell transplantation mortality has declined over the years, though prevention and management of treatment-related toxicities and post-transplant complications remains challenging. Applications of pharmacogenomic testing can potentially mitigate adverse drug outcomes due to interindividual variability in drug metabolism and response. This review summarizes clinical pharmacogenomic applications relevant to hematopoietic stem cell transplantation, including antifungals, immunosuppressants, and supportive care management, as well as emerging pharmacogenomic evidence with conditioning regimens.

Contrasting ABCB1 pharmacogenetics and psychotropic responses in child and adolescent psychiatry: a case comparison

This case comparison illustrates pharmacogenetic testing in psychotropic and clinical management in relation to the ABCB1 gene, which encodes the P-glycoprotein transporter affecting blood-brain barrier (BBB) permeability. Two pediatric patients (9 and 11 years old) were selected for similar clinical presentations with opposing ABCB1 genotype, while they were identically matched for key CYP450, dopaminergic and serotonergic genes (CYP2C9, CYP2C19, DRD2, SLC6A4, 5HTR2A). Case A was functional for the ABCB1 gene (G/G rs1045642), suggesting that the BBB had a functional P-glycoprotein transporter. Case B was subfunctional for the ABCB1 gene (A/A rs1045642), suggesting that the patient's BBB may be permeable to psychotropic drugs. Case A had more medication trials and dose adjustments than Case B. Case A had two inpatient admissions and interspersed emergency room visits, while case B had none.

Precision Medicine in Antidepressants Treatment

Precision medicine uses innovative approaches to improve disease prevention and treatment outcomes by taking into account people's genetic backgrounds, environments, and lifestyles. Treatment of depression is particularly challenging, given that 30-50% of patients do not respond adequately to antidepressants, while those who respond may experience unpleasant adverse drug reactions (ADRs) that decrease their quality of life and compliance. This chapter aims to present the available scientific data that focus on the impact of genetic variants on the efficacy and toxicity of antidepressants. We compiled data from candidate gene and genome-wide association studies that investigated associations between pharmacodynamic and pharmacokinetic genes and response to antidepressants regarding symptom improvement and ADRs. We also summarized the existing pharmacogenetic-based treatment guidelines for antidepressants, used to guide the selection of the right antidepressant and its dose based on the patient's genetic profile, aiming to achieve maximum efficacy and minimum toxicity. Finally, we reviewed the clinical implementation of pharmacogenomics studies focusing on patients on antidepressants. The available data demonstrate that precision medicine can increase the efficacy of antidepressants and reduce the occurrence of ADRs and ultimately improve patients' quality of life.

Identification and in vitro functional assessment of 10 CYP2C9 variants found in Chinese Han subjects

Cytochrome P450 2C9 (CYP2C9) participates in about 15% of clinical drug metabolism, and its polymorphism is associated with individual drug metabolism differences, which may lead to the adverse drug reactions (ADRs). In this study, 1163 Chinese Han individuals were recruited to investigate their distribution pattern of CYP2C9 gene and find out the variants that may affect their drug metabolic activities. We successfully developed a multiplex PCR amplicon sequencing method and used it for the genetic screening of CYP2C9 in a large scale. Besides the wild type CYP2C9*1, totally 26 allelic variants of CYP2C9 were detected, which included 16 previously reported alleles and 10 new non-synonymous variants that had not been listed on the PharmVar website. The characteristics of these newly detected CYP2C9 variants were then evaluated after co-expressing them with CYPOR in S. cerevisiae microsomes. Immunoblot analysis revealed that except for Pro163Ser, Glu326Lys, Gly431Arg and Ile488Phe, most of newly detected variants showed comparable protein expression levels to wild type in yeast cells. Two typical CYP2C9 probe drugs, losartan and glimepiride, were then used for the evaluation of metabolic activities of variants. As a result, 3 variants Thr301Met, Glu326Lys, and Gly431Arg almost lost their catalytic activities and most of other variants exhibited significantly elevated activities for drug metabolism. Our data not only enriches the knowledge of naturally occurring CYP2C9 variants in the Chinese Han population, but also provides the fundamental evidence for its potential clinical usage for personalized medicine in the clinic.

Pharmacogenetic Dose Modeling Based on CYP2C19 Allelic Phenotypes

Pharmacogenetic variability in drug metabolism leads to patient vulnerability to side effects and to therapeutic failure. Our purpose was to introduce a systematic statistical methodology to estimate quantitative dose adjustments based on pharmacokinetic differences in pharmacogenetic subgroups, addressing the concerns of sparse data, incomplete information on phenotypic groups, and heterogeneity of study design. Data on psychotropic drugs metabolized by the cytochrome P450 enzyme CYP2C19 were used as a case study. CYP2C19 activity scores were estimated, while statistically assessing the influence of methodological differences between studies, and used to estimate dose adjustments in genotypic groups. Modeling effects of activity scores in each substance as a population led to prudential predictions of adjustments when few data were available ('shrinkage'). The best results were obtained with the regularized horseshoe, an innovative Bayesian approach to estimate coefficients viewed as a sample from two populations. This approach was compared to modeling the population of substance as normally distributed, to a more traditional "fixed effects" approach, and to dose adjustments based on weighted means, as in current practice. Modeling strategies were able to assess the influence of study parameters and deliver adjustment levels when necessary, extrapolated to all phenotype groups, as well as their level of uncertainty. In addition, the horseshoe reacted sensitively to small study sizes, and provided conservative estimates of required adjustments.

Pediatric considerations for pharmacogenetic selective serotonin reuptake inhibitors clinical decision support

Pharmacogenetic testing for psychiatry is growing at a rapid pace, with multiple sites utilizing results to help clinical decision-making. Genotype-guided dosing and drug selection have been implemented at several sites, including Vanderbilt University Medical Center, where clinical decision support (CDS) based on pharmacogenetic results went live for selective serotonin reuptake inhibitors in 2020 for both adult and pediatric patients. Effective and appropriate implementation of CYP2D6- and CYP2C19-guided CDS for the pediatric population requires consideration of the evidence for the pharmacogenetic associations, medication indications, and appropriate alternative therapies to be used when a pharmacogenetic contraindication is identified. In this article, we review these pediatric pharmacogenetic considerations for selective serotonin reuptake inhibitor CDS. We include a case study, the current literature supporting clinical recommendations, considerations when designing pediatric CDS, future implications, and examples of sertraline, (es)citalopram, paroxetine, and fluvoxamine alerts.

Impact of the novel CYP2C:TG haplotype and CYP2B6 variants on sertraline exposure in a large patient population

Sertraline is a commonly used SSRI antidepressant drug, metabolized by CYP2C19 and CYP2B6, that exhibits a substantial interindividual variation in clinical response, of which only a part can be attributed to known genetic variants. In the current study we have examined the role of a newly discovered ultrarapid CYP2C:TG haplotype and CYP2B6 variants in order to identify the possible missing heritability for such variation in sertraline response in a large patient population (n = 840). Compared to the reference group (CYP2C19*1/*1, n = 160), sertraline exposure was increased by 128% in CYP2C19 PMs (n = 29, p < 0.001) but decreased by about 20% in CYP2C19 ultrarapid metabolizers (Ums) (homozygous carriers of CYP2C19*17 and/or CYP2C:TG haplotype) with the diplotypes CYP2C19*17/*17, CYP2C:TG/TG, or CYP2C19*17/CYP2C:TG (n = 135, p < 0.003, p = 0.022, p < 0.003, respectively). Interestingly, in patients carrying the increased function CYP2B6*4 allele, and also carrying the CYP2C19*17 and CYP2C:TG alleles (n = 10), sertraline exposure was 35.4% lower compared to the reference group, whereas in subjects being poor metabolizers (PM) in both the CYP2C19 and CYP2B6 gene, the sertraline concentrations were raised by 189%. In summary, the CYP2C19 variants including the CYP2C:TG haplotype had a significant impact on sertraline metabolism, as well as the CYP2B6*4, *6, and *9 alleles. Knowing the CYP2B6 and CYP2C19 genotype, including the CYP2C:TG haplotype status, can prospectively be useful to clinicians in making more appropriate sertraline dosing decisions.

Pharmacogenetics of Donepezil and Memantine in Healthy Subjects

Donepezil and memantine are the most common drugs used for Alzheimer’s disease. Their low effectiveness could partly be explained by genetic factors. Thus, we aim to identify Single Nucleotide Polymorphisms (SNPs) associated with pharmacokinetics, pharmacodynamics, and the safety of donepezil and memantine. For this regard, 25 volunteers enrolled in a bioequivalence clinical trial were genotyped for 67 SNPs in 21 genes with a ThermoFisher QuantStudio 12K Flex OpenArray. The statistical strategy included a univariate analysis that analyzed the association of these SNPs with pharmacokinetic parameters or the development of adverse drug reactions (ADRs) followed by a Bonferroni-corrected multivariate regression. Statistical analyses were performed with SPSS software v.21 and R commander (version v3.6.3). In the univariate analysis, fourteen and sixteen SNPs showed a significant association with memantine’s and donepezil’s pharmacokinetic parameters, respectively. Rs20417 (PTGS2) was associated with the development of at least one ADR. However, none of these associations reached the significance threshold in the Bonferroni-corrected multivariate analysis. In conclusion, we did not observe any significant association of the SNPs analyzed with memantine and donepezil pharmacokinetics or ADRs. Current evidence on memantine and donepezil pharmacogenetics does not justify their inclusion in pharmacogenetic guidelines.

Comparison between cannabidiol and sertraline for the modulation of post-traumatic stress disorder-like behaviors and fear memory in mice

RATIONALE AND OBJECTIVES

Post-traumatic stress disorder (PTSD) is characterized by poor adaptation to a traumatic experience and disturbances in fear memory regulation, and currently lacks effective medication. Cannabidiol is a main constituent of Cannabis sativa; it has no psychotomimetic effects and has been implicated in modulating fear learning in mammals. Using a mouse PTSD model, we investigated the effects of CBD on PTSD-like behaviors and the modulation of trauma-related fear memory, a crucial process leading to core symptoms of PTSD.

METHODS

We applied the modified pre-shock model to evaluated PTSD-like behaviors from days 3 to 26. The measures included the freezing time to the conditioned context, open field test, elevated plus maze test, and social interaction test. CBD and sertraline were administered at different stages of fear memory.

RESULTS

CBD (10 mg/kg, i.p.) administration alleviated main PTSD-like symptoms in the mouse pre-shock model by attenuating trauma-related fear memory and anxiety-like behavior, and increasing social interaction behavior. The effects of CBD were apparent irrespective of whether it was administered before, during, or after re-exposure to the aversive context. However, sertraline (15 mg/kg, p.o.) was only effective when administered before the behavioral test. CBD also reduced the consolidation, retrieval, and reconsolidation of trauma-related fear memory, whereas sertraline only reduced fear-memory retrieval.

CONCLUSION

CBD produced anti-PTSD-like actions in mice and disrupted trauma-related fear memory by interfering with multiple aspects of fear memory processing. These findings indicate that CBD may be a promising candidate for treating PTSD.

Combinatorial pharmacogenomic algorithm is predictive of sertraline metabolism in patients with major depressive disorder

Pharmacogenomic testing can be used to guide medication selection in patients with major depressive disorder (MDD). Currently, there is no consensus on which gene or genes to consider in medication management. Here, we assessed the clinical validity of the combinatorial pharmacogenomic algorithm to predict sertraline blood levels in a subset of patients enrolled in the Genomics Used to Improve DEpression Decisions (GUIDED) trial. Patients who reported taking sertraline within ≤2 weeks of the screening blood draw were included. All patients received combinatorial pharmacogenomic testing, which included a weighted assessment of individual phenotypes for multiple pharmacokinetic genes relevant for sertraline (CYP2C19, CYP2B6, and CYP3A4). Sertraline blood levels were compared between phenotypes based on: 1) the pharmacokinetic portion of the combinatorial pharmacogenomic algorithm, and 2) individual genes. When evaluated separately, individual genes (for CYP2C19 and CYP2B6) and the combinatorial algorithm were significant predictors of sertraline blood levels. However, in multivariate analyses that included individual genes and the combinatorial pharmacogenomic algorithm, only the combinatorial pharmacogenomic algorithm remained a significant predictor of sertraline blood levels. These findings support the clinical validity of the combinatorial pharmacogenomic algorithm, in that it is a superior predictor of sertraline blood levels compared to individual genes.

The Effects of Bariatric Surgery and Gastrectomy on the Absorption of Drugs, Vitamins, and Mineral Elements

Bariatric surgery, which is an effective treatment for obesity, and gastrectomy, which is the primary treatment method for gastric cancer, alter the anatomy and physiology of the digestive system. Weight loss and changes in the gastrointestinal tract may affect the pharmacokinetic parameters of oral medications. Both bariatric and cancer patients use drugs chronically or temporarily. It is important to know how surgery affects their pharmacokinetics to ensure an effective and safe therapy. The Cochrane, PubMed, and Scopus databases were searched independently by two authors. The search strategy included controlled vocabulary and keywords. Studies show that bariatric surgery and gastrectomy most often reduce the time to maximum plasma concentration (t_max) and decrease the maximum plasma concentration (C_max) in comparison with the values of these parameters measured in healthy volunteers. Vitamin and mineral deficiencies are also observed. The effect depends on the type of surgery and the properties of the drug. It is recommended to use the drugs that have been tested on these groups of patients as it is possible to monitor them.

Implications of Cannabidiol in Pharmacogenomic-Based Drug Interactions with CYP2C19 Substrates

This is a patient case exploring the importance of evaluating herbal and dietary supplements and how they may impact drug-drug and drug-gene implications based on pharmacogenomics test results. Even though herbal supplements are considered natural by many patients, which is often the reason for starting them, herbal supplements may still be metabolized by the same pathways as other medications, potentially contributing to drug-drug, drug-herb, and drug-gene interactions, and therefore, potentially impacting a patient's response to medications.

The role of pharmacogenetics in the treatment of anxiety disorders and the future potential for targeted therapeutics

INTRODUCTION

Anxiety disorders (AD) are among the most common mental disorders worldwide. Pharmacotherapy, including benzodiazepines, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and tricyclic antidepressants is currently based on 'trial-and-error,' and is effective in a subset of patients or produces partial response only. Recent research proposes that treatment response and tolerability of the drugs are associated with genetic factors.

AREAS COVERED

In the present review, we provide information on pharmacogenetics (PGx) in AD, including pharmacokinetic and pharmacodynamic genes. Moreover, we discuss the future potential of PGx for personalized treatment.

EXPERT OPINION

In psychiatry, PGx testing is still in its infancy, especially in the treatment of AD. As of today, implementation in clinical routine is recommended only for CYP2D6 and CYP2C19, mainly in terms of safety of treatment and potentially of treatment outcome in general. However, the evidence for PGx testing addressing pharmacodynamics for specific AD is limited to date. Nevertheless, PGx may develop into a valuable and promising tool to improve therapy in AD, but there is a need for more research to fully exploit its possibilities. Future perspectives include research into single genes, polygenic risk scores, and pharmacoepigenetics to provide targeted therapy.

Tools for optimising pharmacotherapy in psychiatry (therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests): focus on antidepressants

Objectives: More than 40 drugs are available to treat affective disorders. Individual selection of the optimal drug and dose is required to attain the highest possible efficacy and acceptable tolerability for every patient.Methods: This review, which includes more than 500 articles selected by 30 experts, combines relevant knowledge on studies investigating the pharmacokinetics, pharmacodynamics and pharmacogenetics of 33 antidepressant drugs and of 4 drugs approved for augmentation in cases of insufficient response to antidepressant monotherapy. Such studies typically measure drug concentrations in blood (i.e. therapeutic drug monitoring) and genotype relevant genetic polymorphisms of enzymes, transporters or receptors involved in drug metabolism or mechanism of action. Imaging studies, primarily positron emission tomography that relates drug concentrations in blood and radioligand binding, are considered to quantify target structure occupancy by the antidepressant drugs in vivo. Results: Evidence is given that in vivo imaging, therapeutic drug monitoring and genotyping and/or phenotyping of drug metabolising enzymes should be an integral part in the development of any new antidepressant drug.Conclusions: To guide antidepressant drug therapy in everyday practice, there are multiple indications such as uncertain adherence, polypharmacy, nonresponse and/or adverse reactions under therapeutically recommended doses, where therapeutic drug monitoring and cytochrome P450 genotyping and/or phenotyping should be applied as valid tools of precision medicine.

ABCB1 C3435T, G2677T/A and C1236T variants have no effect in eslicarbazepine pharmacokinetics

Eslicarbazepine acetate is a third-generation anti-epileptic prodrug quickly and extensively transformed to eslicarbazepine after oral administration. Reduction in seizure frequency in patients managed with eslicarbazepine is only partial in the majority of patients and many of them suffer considerable ADRs that require a change of treatment. The P-glycoprotein, encoded by the ABCB1 gene, is expressed throughout the body and can impact the pharmacokinetics of several drugs. In terms of epilepsy treatment, this transporter was linked to drug-resistant epilepsy, as it conditions drug access into the brain due to its expression at the blood-brain barrier. Therefore, we aimed to investigate the impact of three ABCB1 common polymorphisms (i.e., C3435T, or rs1045642, G2677A or rs2032582 and C1236T or rs1128503) in the pharmacokinetics and safety of eslicarbazepine. For this purpose, 22 healthy volunteers participating in a bioequivalence clinical trial were recruited. No significant relationship was observed between sex, race and ABCB1 polymorphism and eslicarbazepine pharmacokinetic variability. In contrast, ABCB1 C1236T C/C diplotype was significantly related to the occurrence of ADRs: one volunteer with this genotype suffered dizziness, somnolence and hand paresthesia, while no other volunteer suffered any of these ADRs (p < 0.045). To the best of our knowledge, this is the first study published to date evaluating eslicarbazepine pharmacogenetics. Further studies with large sample sizes are needed to compare the results obtained here.

Reversible Complete Heart Block in a Pregnant Woman Related to Sertraline Treatment

Complete heart block (CHB) is a serious condition, usually affecting older patients. We report a case of CHB in a 31-year-old pregnant woman treated with sertraline in whom atrioventricular (AV) conduction normalized after discontinuation of sertraline. Results of subsequent genetic investigations for inherited cardiomyopathy and ion-channel disease and a pharmacogenetic study of sertraline pharmacokinetics were negative. Reversible CHB in this younger pregnant patient was temporally related to sertraline. This case underlines the importance of identifying reversible causes when a young patient presents with AV block with unknown trajectory and prognosis, as well as regular recording of electrocardiograms in pregnant patients on psychotropic medications.

Precision Medicine into Clinical Practice: A Web-Based Tool Enables Real-Time Pharmacogenetic Assessment of Tailored Treatments in Psychiatric Disorders

The management of neuropsychiatric disorders involves different pharmacological treatments. In order to perform efficacious drug treatments, the metabolism of CYP genes can help to foresee potential drug–drug interactions. The NeuroPGx software is an open-source web-based tool for genotype/diplotype/phenotype interpretation for neuropharmacogenomic purposes. The software provides information about: (i) the genotypes of evaluated SNPs (single nucleotide polymorphisms); (ii) the main diplotypes in CYP genes and corresponding metabolization phenotypes; (iii) the list of neuropsychiatric drugs with recommended dosage adjustment (according to CPIC and DPWG guidelines); (iv) the list of possible (rare) diplotypes and corresponding metabolization phenotypes. The combined application of NeuroPGx software to the OpenArray technology results in an easy, quick, and highly automated device ready to be used in routine clinical practice.

PriME-PGx: La Princesa University Hospital Multidisciplinary Initiative for the Implementation of Pharmacogenetics

The implementation of clinical pharmacogenetics in daily practice is limited for various reasons. Today, however, it is a discipline in full expansion. Accordingly, in the recent times, several initiatives promoted its implementation, mainly in the United States but also in Europe. In this document, the genotyping results since the establishment of our Pharmacogenetics Unit in 2006 are described, as well as the historical implementation process that was carried out since then. Finally, this progress justified the constitution of La Princesa University Hospital Multidisciplinary Initiative for the Implementation of Pharmacogenetics (PriME-PGx), promoted by the Clinical Pharmacology Department of Hospital Universitario de La Princesa (Madrid, Spain). Here, we present the initiative along with the two first ongoing projects: the PROFILE project, which promotes modernization of pharmacogenetic reporting (i.e., from classic gene-drug pair reporting to complete pharmacogenetic reporting or the creation of pharmacogenetic profiles specific to the Hospital’s departments) and the GENOTRIAL project, which promotes the communication of relevant pharmacogenetic findings to any healthy volunteer participating in any bioequivalence clinical trial at the Clinical Trials Unit of Hospital Universitario de La Princesa (UECHUP).

Therapy response prediction in major depressive disorder: current and novel genomic markers influencing pharmacokinetics and pharmacodynamics

Major depressive disorder is connected with high rates of functional disability and mortality. About a third of the patients are at risk of therapy failure. Several pharmacogenetic markers especially located in CYP450 genes such as CYP2D6 or CYP2C19 are of relevance for therapy outcome prediction in major depressive disorder but a further optimization of predictive tools is warranted. The article summarizes the current knowledge on pharmacogenetic variants, therapy effects and side effects of important antidepressive therapeutics, and sheds light on new methodological approaches for therapy response estimation based on genetic markers with relevance for pharmacokinetics, pharmacodynamics and disease pathology identified in genome-wide association study analyses, highlighting polygenic risk score analysis as a tool for further optimization of individualized therapy outcome prediction.

The application of precision dosing in the use of sertraline throughout pregnancy for poor and ultrarapid metabolizer CYP 2C19 subjects: A virtual clinical trial pharmacokinetics study

Sertraline is known to undergo changes in pharmacokinetics during pregnancy. CYP 2C19 has been implicated in the interindividual variation in clinical effect associated with sertraline activity. However, knowledge of suitable dose titrations during pregnancy and within CYP 2C19 phenotypes is lacking. A pharmacokinetic modeling virtual clinical trials approach was implemented to: (i) assess gestational changes in sertraline trough plasma concentrations for CYP 2C19 phenotypes, and (ii) identify appropriate dose titration strategies to stabilize sertraline levels within a defined therapeutic range throughout gestation. Sertraline trough plasma concentrations decreased throughout gestation, with maternal volume expansion and reduction in plasma albumin being identified as possible causative reasons. All CYP 2C19 phenotypes required a dose increase throughout gestation. For extensive metabolizer (EM) and ultrarapid metabolizer (UM) phenotypes, doses of 100-150 mg daily are required throughout gestation. For poor metabolizers (PM), 50 mg daily during trimester 1 followed by a dose of 100 mg daily in trimesters 2 and 3 are required.

Sertraline concentrations in pregnant women are steady and the drug transfer to their infants is low

Purpose

Sertraline, a selective serotonin reuptake inhibitor (SSRI), is one of the most commonly used antidepressant during pregnancy. Plasma sertraline concentrations vary markedly between individuals, partly explained by variability in hepatic drug metabolizing cytochrome P450-enzyme activity. Our purpose was to study the variability in the plasma concentrations in pregnant women and the passage to their infants.

Method

Pregnant women with moderate untreated depression were recruited in 2016–2019 in Stockholm Region and randomized to treatment with sertraline or placebo. All received Internet-based cognitive behavior therapy as non-medical treatment. Sertraline plasma concentrations were measured around pregnancy weeks 21 and 30, at delivery, 1-month postpartum, in cord blood and at 48 h of age in the infant. The clinical course of the infants was followed.

Results

Nine mothers and 7 infants were included in the analysis. Median dose-adjusted sertraline concentration in second trimester was 0.15(ng/mL) /(mg/day), in third trimester and at delivery 0.19 and 1-month postpartum 0.25, with a 67% relative difference between second trimester and postpartum. The interindividual variation was 10-fold. Median concentrations in the infants were 33% and 25% of their mothers’, measured in cord blood, and infant plasma, respectively. Only mild and transient adverse effects were seen on the infants.

Conclusion

Placental passage of sertraline to the infant is low. However, the interindividual variation in maternal concentrations during pregnancy is huge, why therapeutic drug monitoring might assist in finding the poor metabolizers at risk for adversity and increase the safety of the treatment.

Trial registration

The trial was registered at clinicaltrials.gov July 9, 2014 with TRN: NCT02185547.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-021-03122-z.

Acceptability, Feasibility, and Utility of Integrating Pharmacogenetic Testing into a Child Psychiatry Clinic

Pharmacogenetic (PGx) testing is a tool to identify patients at a higher risk of adverse events or treatment failure. The concern for unwanted side effects can limit medication adherence, particularly in children and adolescents. We conducted a pragmatic study to evaluate the acceptability and feasibility and gather pilot data on the utility of PGx testing in a child and adolescent psychiatry clinic. Both physicians and families participated in the study and answered pre‐survey and post‐survey questionnaires to examine their attitudes toward PGx testing. Patients were randomized into implementation (N = 25) and control groups (N = 24) and underwent PGx testing at the beginning or end of the study, respectively. Clinical consult notes with genotype‐guided recommendations were provided to physicians for their consideration in clinical decisions. Patient‐reported symptom severity and antidepressant‐related side effects were assessed at baseline and for 12 weeks. Both participating physicians and families agreed that PGx testing is a useful tool to improve medication selection. The time from sample collection to having PGx test results was ~ 10 days and 15 days to having consult notes available, which may have impaired test utility in clinical decision making. There were no differences in any clinical end point between the implementation and control arms; however, there were higher antidepressant side effect scores for CYP2D6 poor and intermediate metabolizers after the eighth week of treatment. Our findings revealed benefits and pitfalls with the use of PGx testing in the real‐world clinical setting, which may inform the methodology of a larger trial focused on outcomes.

Involvement of CYP2D6 and CYP2B6 on tramadol pharmacokinetics

This study included 24 healthy volunteers who received a single 37.5 mg oral dose of tramadol. We analyzed 18 polymorphisms within CYP2D6, CYP2B6, CYP3A, COMT, ABCB1, SLC22A1 and OPRM1 genes by quantitative PCR, to study whether these polymorphisms affect its pharmacokinetics, pharmacodynamics and safety. CYP2D6 intermediate metabolizers (n = 6) showed higher tramadol plasma concentrations and lower clearance compared with normal and ultrarapid metabolizers. CYP2B6 G516T T/T (n = 2) genotype was also associated to higher tramadol plasma levels. No other polymorphism affected tramadol pharmacokinetics. Three volunteers experienced a prolonged QTc not associated with the genetic variants studied or altered phamacokinetic parameters. The correlation of CYP2B6 genotype with higher tramadol concentrations is remarkable since its influence on its elimination is also relevant and has been less studied to date. However, given our small sample size, it is important to interpret our results with caution.

The atorvastatin metabolic phenotype shift is influenced by interaction of drug-transporter polymorphisms in Mexican population: results of a randomized trial

Atorvastatin (ATV) is a blood cholesterol-lowering drug used to prevent cardiovascular events, the leading cause of death worldwide. As pharmacokinetics, metabolism and response vary among individuals, we wanted to determine the most reliable metabolic ATV phenotypes and identify novel and preponderant genetic markers that affect ATV plasma levels. A controlled, randomized, crossover, single-blind, three-treatment, three-period, and six-sequence clinical study of ATV (single 80-mg oral dose) was conducted among 60 healthy Mexican men. ATV plasma levels were measured using high-performance liquid chromatography mass spectrometry. Genotyping was performed by real-time PCR with TaqMan probes. Four ATV metabolizer phenotypes were found: slow, intermediate, normal and fast. Six gene polymorphisms, SLCO1B1-rs4149056, ABCB1-rs1045642, CYP2D6-rs1135840, CYP2B6-rs3745274, NAT2-rs1208, and COMT- rs4680, had a significant effect on ATV pharmacokinetics (P < 0.05). The polymorphisms in SLCO1B1 and ABCB1 seemed to have a greater effect and were especially important for the shift from an intermediate to a normal metabolizer. This is the first study that demonstrates how the interaction of genetic variants affect metabolic phenotyping and improves understanding of how SLCO1B1 and ABCB1 variants that affect statin metabolism may partially explain the variability in drug response. Notwithstanding, the influence of other genetic and non-genetic factors is not ruled out.

Population Pharmacokinetics of Sertraline in Healthy Subjects: a Model-Based Meta-analysis

Sertraline pharmacokinetics is poorly understood and highly variable due to large between-subject variability with inconsistent reports for oral bioavailability. The study objective was to characterize sertraline pharmacokinetics by developing and validating a sertraline population pharmacokinetic (PK) model in healthy subjects using published clinical PK data. We carried a systematic literature search in PubMed in October 2015 and identified 27 pharmacokinetic studies of sertraline conducted in healthy adult subjects and reported in the English language. Sixty mean plasma concentration-time profiles made of 748 plasma concentrations following IV, single, and multiple oral doses ranging from 5 to 400 mg were extracted and analyzed for dose proportionality by a log-linear model and fitted to a 2-compartment pharmacokinetic model in NONMEM using a model-based meta-analysis (MBMA) approach. After a single oral dose, sertraline C_max and AUC_∞ increased with dose proportionally between 50 and 200 mg, and bioavailability increased nonlinearly with dose from 5 to 50 mg and plateaued afterwards while T_max and t_1/2 did not change with dose. Following multiple oral doses, C_max and AUC_∞ increased proportionally with dose across the entire dose range (5-200 mg) while bioavailability, T_max, and t_1/2 remained constant with dose. Sertraline absorption was time-dependent and best described by a sigmoidal E_max function of time after dose. Study findings indicate that sertraline PK is linear in healthy adult subjects at doses ≥ 50 mg, and exposures were nonlinear only after single oral doses < 50 mg likely due to reduced bioavailability.

The role of hepatic cytochrome P450s in the cytotoxicity of sertraline

Sertraline, an antidepressant, is commonly used to manage mental health symptoms related to depression, anxiety disorders, and obsessive-compulsive disorder. The use of sertraline has been associated with rare but severe hepatotoxicity. Previous research demonstrated that mitochondrial dysfunction, apoptosis, and endoplasmic reticulum stress were involved in sertraline-associated cytotoxicity. In this study, we reported that after a 24-h treatment in HepG2 cells, sertraline caused cytotoxicity, suppressed topoisomerase I and IIα, and damaged DNA in a concentration-dependent manner. We also investigated the role of cytochrome P450 (CYP)-mediated metabolism in sertraline-induced toxicity using our previously established HepG2 cell lines individually expressing 14 CYPs (1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 3A4, 3A5, and 3A7). We demonstrated that CYP2D6, 2C19, 2B6, and 2C9 metabolize sertraline, and sertraline-induced cytotoxicity was significantly decreased in the cells expressing these CYPs. Western blot analysis demonstrated that the induction of ɣH2A.X (a hallmark of DNA damage) and topoisomerase inhibition were partially reversed in CYP2D6-, 2C19-, 2B6-, and 2C9-overexpressing HepG2 cells. These data indicate that DNA damage and topoisomerase inhibition are involved in sertraline-induced cytotoxicity and that CYPs-mediated metabolism plays a role in decreasing the toxicity of sertraline.

The effects of aripiprazole and olanzapine on pupillary light reflex and its relationship with pharmacogenetics in a randomized multiple-dose trial

Aims

Pupillography is a noninvasive and cost‐effective method to determine autonomic nerve activity. Genetic variants in cytochrome P450 (CYP), dopamine receptor (DRD2, DRD3), serotonin receptor (HTR2A, HTR2C) and ATP‐binding cassette subfamily B (ABCB1) genes, among others, were previously associated with the pharmacokinetics and pharmacodynamics of antipsychotic drugs. Our aim was to evaluate the effects of aripiprazole and olanzapine on pupillary light reflex related to pharmacogenetics.

Methods

Twenty‐four healthy volunteers receiving 5 oral doses of 10 mg aripiprazole and 5 mg olanzapine tablets were genotyped for 46 polymorphisms by quantitative polymerase chain reaction. Pupil examination was performed by automated pupillometry. Aripiprazole, dehydro‐aripiprazole and olanzapine plasma concentrations were measured by high‐performance liquid chromatography–tandem mass spectrometry.

Results

Aripiprazole affected pupil contraction: it caused dilatation after the administration of the first dose, then caused constriction after each dosing. It induced changes in all pupillometric parameters (P < .05). Olanzapine only altered minimum pupil size (P = .046). Polymorphisms in CYP3A, HTR2A, UGT1A1, DRD2 and ABCB1 affected pupil size, the time of onset of constriction, pupil recovery and constriction velocity. Aripiprazole, dehydro‐aripiprazole and olanzapine pharmacokinetics were significantly affected by polymorphisms in CYP2D6, CYP3A, CYP1A2, ABCB1 and UGT1A1 genes.

Conclusions

In conclusion, aripiprazole and its main metabolite, dehydro‐aripiprazole altered pupil contraction, but olanzapine did not have such an effect. Many polymorphisms may influence pupillometric parameters and several polymorphisms had an effect on aripiprazole, dehydro‐aripiprazole and olanzapine pharmacokinetics. Pupillography could be a useful tool for the determination of autonomic nerve activity during antipsychotic treatment.

Impact of CYP2C19 genotype on sertraline exposure in 1200 Scandinavian patients

Sertraline is an (SSRI-)antidepressant metabolized by the polymorphic CYP2C19 enzyme. The aim of this study was to investigate the impact of CYP2C19 genotype on the serum concentrations of sertraline in a large patient population. Second, the proportions of patients in the various CYP2C19 genotype-defined subgroups obtaining serum concentrations outside the therapeutic range of sertraline were assessed. A total of 2190 sertraline serum concentration measurements from 1202 patients were included retrospectively from the drug monitoring database at Diakonhjemmet Hospital in Oslo. The patients were divided into CYP2C19 genotype-predicted phenotype subgroups, i.e. normal (NMs), ultra rapid (UMs), intermediate (IMs), and poor metabolisers (PMs). The differences in dose-harmonized serum concentrations of sertraline and N-desmethylsertraline-to-sertraline metabolic ratio were compared between the subgroups, with CYP2C19 NMs set as reference. The patient proportions outside the therapeutic concentration range were also compared between the subgroups with NMs defined as reference. Compared with the CYP2C19 NMs, the sertraline serum concentration was increased 1.38-fold (95% CI 1.26-1.50) and 2.68-fold (95% CI 2.16-3.31) in CYP2C19 IMs and PMs, respectively (p < 0.001), while only a marginally lower serum concentration (-10%) was observed in CYP2C19 UMs (p = 0.012). The odds ratio for having a sertraline concentration above the therapeutic reference range was 1.97 (95% CI 1.21-3.21, p = 0.064) and 8.69 (95% CI 3.88-19.19, p < 0.001) higher for IMs and PMs vs. NMs, respectively. CYP2C19 IMs and PMs obtain significantly higher serum concentrations of sertraline than NMs. Based on the relative differences in serum concentrations compared to NMs, dose reductions of 60% and 25% should be considered in PMs and IMs, respectively, to reduce the risk of sertraline overexposure in these patients.

Pharmacogenetics of amfepramone in healthy Mexican subjects reveals potential markers for tailoring pharmacotherapy of obesity: results of a randomised trial

Amfepramone (AFP) is an appetite-suppressant drug used in the treatment of obesity. Nonetheless, studies on interindividual pharmacokinetic variability and its association with genetic variants are limited. We employed a pharmacokinetic and pharmacogenetic approach to determine possible metabolic phenotypes of AFP and identify genetic markers that could affect the pharmacokinetic variability in a Mexican population. A controlled, randomized, crossover, single-blind, two-treatment, two-period, and two sequence clinical study of AFP (a single 75 mg dose) was conducted in 36 healthy Mexican volunteers who fulfilled the study requirements. Amfepramone plasma levels were measured using high-performance liquid chromatography mass spectrometry. Genotyping was performed using real-time PCR with TaqMan probes. Four AFP metabolizer phenotypes were found in our population: slow, normal, intermediate, and fast. Additionally, two gene polymorphisms, ABCB1-rs1045642 and CYP3A4-rs2242480, had a significant effect on AFP pharmacokinetics (P < 0.05) and were the predictor factors in a log-linear regression model. The ABCB1 and CYP3A4 gene polymorphisms were associated with a fast metabolizer phenotype. These results suggest that metabolism of AFP in the Mexican population is variable. In addition, the genetic variants ABCB1-rs1045642 and CYP3A4-rs2242480 may partially explain the AFP pharmacokinetic variability.

In-vitro and in situ assessment of the efflux of five antidepressants by breast cancer resistance protein

Objectives

Antidepressants need to penetrate the blood–brain barrier (BBB) to exert their functions in the central nervous system. Breast cancer resistance protein (BCRP), an efflux transporter abundantly expressed in the BBB, prevents the accumulation of many drugs in the brain. This study aimed to identify whether five commonly used antidepressants (sertraline, duloxetine, fluoxetine, amitriptyline and mirtazapine) are BCRP substrates.

Methods

A combination of bidirectional transport and intracellular accumulation experiments was conducted on BCRP-overexpressing MDCKII and wild-type (WT) cells, and in situ brain perfusion was conducted in rats.

Key findings

The bidirectional transport study revealed that the net efflux ratio (NER) of sertraline reached 2.08 but decreased to 1.06 when co-incubated with Ko143, a selective BCRP inhibitor. Conversely, the other four antidepressants did not appear to be BCRP substrates, due to their low NER values (&lt;1.5). The accumulation of sertraline in MDCKII-BCRP cells was significantly lower than that in MDCKII-WT cells. The presence of Ko143 significantly increased the sertraline accumulation in MDCKII-BCRP cells but not in MDCKII-WT cells. Brain perfusion showed that the permeability of 1 and 5 μm sertraline was significantly higher in the presence of Ko143.

Conclusions

Taken together, BCRP is involved in sertraline efflux.

Does obtaining CYP2D6 and CYP2C19 pharmacogenetic testing predict antidepressant response or adverse drug reactions?

Treatment non-response and adverse reactions are common in patients receiving antidepressants. Personalizing psychiatric treatment based on pharmacogenetic testing has been proposed to help clinicians guide antidepressant selection and dosing. This systematic literature review assesses the two most robustly studied drug-metabolizing enzymes, CYP2D6 and CYP2C19, and examines whether obtaining CYP2D6 and CYP2C19 testing can be used to predict antidepressant response or adverse drug reactions in order to improve clinical outcomes. In general, literature reviews published prior to 2013 indicated that results have been inconsistent linking CYP2D6 and CYP2C19 to antidepressant treatment outcomes, suggesting that more evidence is required to support the clinical implementation of genotyping to predict outcomes. We thus performed an extensive and systematic literature review, focusing on studies published from 2013 through 2018. Sixteen studies were found to be relevant. The results yielded inconsistent findings, suggesting that CYP2D6 and CYP2C19 testing may predict response in certain individuals, but it remains unclear if this will translate to improved clinical outcomes. Further research is required to determine when pharmacogenetic testing should be utilized and in which populations it is indicated. Randomized, controlled, prospective trials with adequate sample sizes would best clarify whether genotype-guided antidepressant selection will ultimately improve clinical outcomes.

How to make P-glycoprotein (ABCB1, MDR1) harbor mutations and measure its expression and activity in cell cultures?

Several polymorphisms have been identified in ABCB1, the gene encoding for the P-glycoprotein. This transporter alters the pharmacokinetics or effectiveness of drugs by excreting them from cells where it is expressed (e.g., blood-brain barrier, intestine or tumors). No consensus has been reached regarding the functional consequences of these polymorphisms in the transporter's function. The aim of this review was to describe a methodology that allows the assessment of P-gp function when harboring polymorphisms. We describe how to obtain cell lines with high expression levels of the transporter with polymorphisms and several tactics to measure its expression and activity. This methodology may help elucidate the contribution of polymorphisms in ABCB1 to drug pharmacokinetics, effectiveness and safety or to cancer chemotherapy failure.

MAGDALENA: study protocol of a randomised, placebo-controlled trial on cognitive development at 2 years of age in children exposed to SSRI in utero

INTRODUCTION

Ten per cent of all pregnant women are depressed. Standard therapy of pregnant women with moderate depression is selective serotonin reuptakeinhibitors (SSRI). Observational studies on neurodevelopment after fetal SSRI exposure show conflicting results. Our primary objective is to compare the cognitive development in children exposed to sertraline and maternal depression with those exposed to maternal depression and placebo in utero. We hypothesise that there is a significant neurodevelopmental difference between the groups. As a secondary objective, we study the add-on effect of sertraline to internet-based cognitive behavioural therapy (ICBT) to treat moderate depression during pregnancy.

METHODS AND ANALYSIS

MAGDALENA is a randomised, placebo-controlled, double-blinded trial in Stockholm Healthcare Region with 2.3 million inhabitants. The women are recruited in weeks 9-21 of pregnancy either through Antenatal Health Clinics or through social media. They are to be diagnosed with moderate depression without ongoing antidepressive therapy or any serious comorbidity. The women in the intervention arm receive sertraline combined with a 12-week period of ICBT; the control arm is treated with placebo and ICBT. We assess the cognitive development in the offspring at the age of 2 years using Bayley Scales of Infant and Toddler Development, third edition (BSID-III). We aim at recruiting 200 women, 100 women in each treatment arm, to ensure statistical power to detect a clinically relevant difference between the groups.

ETHICS AND DISSEMINATION

This randomised trial will provide long-sought evidence about the effects of SSRI and maternal depression during pregnancy on the neurodevelopment in the offspring. The study is approved by the Regional Ethical Review Board at Karolinska Institutet in Stockholm and the Swedish Medical Products Agency. It is registered with the European Clinical Trials Database (EudraCT), Number: 2013-004444-31. Results will be disseminated at scientific conferences, published in peer-reviewed journals and made available to the public.

TRIAL REGISTRATION NUMBER

EudraCT2013-004444-31; Pre-results.

Effect of ABCB1 C3435T Polymorphism on Pharmacokinetics of Antipsychotics and Antidepressants

P-glycoprotein, encoded by ABCB1, is an ATP-dependent drug efflux pump which exports substances outside the cell. Some studies described connections between C3435T polymorphism T allele and lower P-glycoprotein expression; therefore, homozygous T/T could show higher plasma levels. Our aim was to evaluate the effect of C3435T on pharmacokinetics of 4 antipsychotics (olanzapine, quetiapine, risperidone and aripiprazole) and 4 antidepressants (trazodone, sertraline, agomelatine and citalopram). The study included 473 healthy volunteers receiving a single oral dose of one of these drugs, genotyped by real-time PCR. Multivariate analysis was performed to adjust the effect of sex and genotype of the main cytochrome P450 enzymes. C3435T polymorphism had an effect on olanzapine pharmacokinetics, as T/T individuals showed lower clearance and volume of distribution. T/T individuals showed lower T_1/2 of 9-OH-risperidone, but this difference disappeared after multivariate correction. T/T homozygous individuals showed lower dehydro-aripiprazole and trazodone area under the concentration-time curve, along with lower half-life and higher clearance of trazodone. C/T genotype was associated to higher citalopram maximum concentration. C3435T had no effect on quetiapine, sertraline or agomelatine pharmacokinetics. C3435T can affect the elimination of some drugs in different ways. Regarding risperidone, trazodone and dehydro-aripiprazole, we observed enhanced elimination while it was reduced in olanzapine and citalopram. However, in quetiapine, aripiprazole, sertraline and agomelatine, no changes were detected. These results suggest that P-glycoprotein polymorphisms could affect CNS drugs disposition, but the genetic factor that alters its activity is still unknown. This fact leads to consider the analysis of ABCB1 haplotypes instead of individual variants.