Pharmacogenetics of Risperidone and Cardiovascular Risk in Children and Adolescents

Pharmacogenomics and non-genetic factors affecting drug response in autism spectrum disorder in Thai and other populations: current evidence and future implications

Autism spectrum disorder (ASD) may affect family and social life profoundly. Although there is no selective pharmacotherapy for ASD, the Food and Drug Administration (FDA) has recommended risperidone/aripiprazole to treat the associated symptoms of ASD, such as agitation/irritability. Strong associations of some pharmacokinetic/pharmacodynamic gene variants, e.g., CYP2D6 and DRD2, with risperidone-induced hyperprolactinemia have been found in children with ASD, but such strong genetic associations have not been found directly for aripiprazole in ASD. In addition to pharmacogenomic (PGx) factors, drug-drug interactions (DDIs) and possibly cumulative effects of DDIs and PGx may affect the safety or effectiveness of risperidone/aripiprazole, which should be assessed in future clinical studies in children with ASD. Reimbursement, knowledge, and education of healthcare professionals are the key obstacles preventing the successful implementation of ASD pharmacogenomics into routine clinical practice. The preparation of national and international PGx-based dosing guidelines for risperidone/aripiprazole based on robust evidence may advance precision medicine for ASD.

Effect of risperidone on serum IL-6 levels in individuals with schizophrenia: a systematic review and meta-analysis

BACKGROUND

Risperidone has been significant correlated with a direct effect of interleukin-6 (IL-6) levels in patients with schizophrenia. This fact allows the opportunity to link the probable immunomodulatory effect of antipsychotic medication. Specially, a proper functioning of IL-6 pathway plays a potential role in the treatment or development of schizophrenia.

OBJECTIVE

Our primary aim was to perform a systematic review and meta-analysis to determine the effect of risperidone on IL-6 levels in individuals with schizophrenia.

METHODS

Studies were identified through a systematic search using PubMed, Scopus, and Web of Science databases. The articles found were subjected to the inclusion and exclusion criteria; then, the mean and standardised differences were extracted to calculate the standardised mean differences using the CMA software.

RESULTS

IL-6 levels in individuals with schizophrenia were compared before and after receiving risperidone as treatment. Increased levels of IL-6 levels were observed in individuals with schizophrenia who received risperidone (point estimate 0.249, lower limit 0.042, upper limit 0.455, p-value 0.018). In the Asian population sub-analysis, no statistically significant differences were observed (point estimate 0.103, lower limit -0.187, upper limit 0.215, p value 0.890). When we compared individuals with schizophrenia to the control groups, a significant increase of IL-6 levels was observed in the group with schizophrenia (point estimate 0.248, lower limit 0.024, upper limit 0.472, p-value 0.30).

CONCLUSIONS

Risperidone appears to play an important role in IL-6 levels in schizophrenia. Potential implications of increased IL-6 levels in people with schizophrenia should be considered in future studies.KEY POINTSIncreased levels of IL-6 levels were observed in individuals with schizophrenia who received risperidone.Risperidone appears to play an important role in IL-6 levels in schizophrenia.This study could serve for future research focussed on IL-6.

Pharmacogenomics in clinical practice to prevent risperidone-induced hyperprolactinemia in autism spectrum disorder

Autism spectrum disorder (ASD) is a global challenge that may disrupts family and social life significantly. There is robust evidence for the association of a pharmacokinetic gene variant (e.g., CYP2D6) with risperidone-induced hyperprolactinemia in ASD. Association of a pharmacodynamic gene variant (e.g., DRD2) with risperidone-induced hyperprolactinemia in ASD is also evident from multiple studies. In addition to genetic factors, dose, duration and drug-drug interactions of risperidone might also increase the serum prolactin level. There are several difficulties, such as reimbursement, knowledge and education of healthcare providers, in implementing risperidone pharmacogenomics into clinical practice. However, preparation of national and international pharmacogenomics-based dosing guidelines of risperidone may advance precision medicine of ASD.

CYP2D6 Genetic Variation and Antipsychotic-Induced Weight Gain: A Systematic Review and Meta-Analysis

BACKGROUND

Antipsychotic-induced weight gain is a contributing factor in the reduced life expectancy reported amongst people with psychotic disorders. CYP2D6 is a liver enzyme involved in the metabolism of many commonly used antipsychotic medications. We investigated if CYP2D6 genetic variation influenced weight or BMI among people taking antipsychotic treatment.

METHODS

We conducted a systematic review and a random effects meta-analysis of publications in Pubmed, Embase, PsychInfo, and CENTRAAL that had BMI and/or weight measurements of patients on long-term antipsychotics by their CYP2D6-defined metabolic groups (poor, intermediate, normal/extensive, and ultra-rapid metabolizers, UMs).

RESULTS

Twelve studies were included in the systematic review. All cohort studies suggested that the presence of reduced-function or non-functional alleles for CYP2D6 was associated with greater antipsychotic-induced weight gain, whereas most cross-sectional studies did not find any significant associations. Seventeen studies were included in the meta-analysis with clinical data of 2,041 patients, including 93 poor metabolizers (PMs), 633 intermediate metabolizers (IMs), 1,272 normal metabolizers (NMs), and 30 UMs. Overall, we did not find associations in any of the comparisons made. The estimated pooled standardized differences for the following comparisons were (i) PM versus NM; weight = -0.07 (95%CI: -0.49 to 0.35, p = 0.74), BMI = 0.40 (95%CI: -0.19 to 0.99, p = 0.19). (ii) IM versus NM; weight = 0.09 (95% CI: -0.04 to 0.22, p = 0.16) and BMI = 0.09 (95% CI: -0.24 to 0.41, p = 0.60). (iii) UM versus EM; weight = 0.01 (95% CI: -0.37 to 0.40, p = 0.94) and BMI = -0.08 (95%CI: -0.57 to 0.42, p = 0.77).

CONCLUSION

Our systematic review of cohort studies suggested that CYP2D6 poor metabolizers have higher BMI than normal metabolizers, but the data of cross-sectional studies and the meta-analysis did not show this association. Although our review and meta-analysis constitutes one of the largest studies with comprehensively genotyped samples, the literature is still limited by small numbers of participants with genetic variants resulting in poor or UMs status. We need further studies with larger numbers of extreme metabolizers to establish its clinical utility in antipsychotic treatment. CYP2D6 is a key gene for personalized prescribing in mental health.

Evidence for Pharmacogenomic Effects on Risperidone Outcomes in Pediatrics

OBJECTIVE

To determine the association between genetic variants reported to affect risperidone and adverse events (AEs) in children and adolescents.

METHODS

Individuals aged 18 years or younger with ≥4 weeks of risperidone exposure in a deidentified DNA biobank were included. The primary outcome was AE frequency as a function of genotype. Individuals were classified according to metabolizer status for CYP2D6, CYP3A4, and CYP3A5; wild type, heterozygote, or homozygote for specific single nucleotide variants for DRD2, DRD3, HTR2A, and HTR2C; and wild type versus nonwild type for multiple uncommon variants in ABCG2, ABCB1, and HTR2C. Tests of association of each classification to AEs were performed using a Fisher exact test and logistic regression, and statistically significant classifications were included in a final logistic regression.

RESULTS

The final cohort included 257 individuals. AEs were more common in CYP2D6 poor/intermediate metabolizers (PMs/IMs) than normal/rapid/ultrarapid metabolizers (NMs/RMs/UMs) in univariate and multivariate analysis. HTR2A-rs6311 heterozygotes and homozygotes had fewer AEs than wild types in logistic regression but not in univariate analysis. In the final multivariable model adjusting for age, race, sex, and risperidone dose, AEs were associated with CYP2D6 (adjusted odds ratio [AOR] 2.6, 95% CI 1.1-5.5, for PMs/IMs vs. NMs/RMs/UMs) and HTR2A-rs6311 (AOR 0.6, 95% CI 0.4-0.9, for each variant allele), both consistent with previous studies.

CONCLUSION

Children and adolescents who are CYP2D6 PMs/IMs may have an increased risk for risperidone AEs. Of the genes and variants studied, only CYP2D6 has consistent association and sufficient data for clinical use, whereas HTR2A-rs6311 has limited data and requires further study.

CYP2D6 and Antipsychotic Treatment Outcomes in Children and Youth: A Systematic Review

Objective: To systematically review the impact of CYP2D6 genetic variation on antipsychotic pharmacokinetics, efficacy, and adverse drug reactions among children and youth. Method: The published literature was systematically searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations and critically evaluated using standardized tools and consensus criteria. Results: A total of 20 eligible studies comprising 1078 children and youth were evaluated. The included studies were of fair to moderate quality and included mostly males, individuals of European ancestry, and those treated with risperidone. CYP2D6 poor metabolizers (PMs) were consistently shown to have increased concentrations of risperidone relative to normal metabolizers (NMs). PMs were also consistently shown to have a greater propensity to experience antipsychotic (primarily risperidone) associated adverse drug reactions relative to NMs. However, robust evidence for an association between CYP2D6 and efficacy was less apparent. Conclusion and Clinical Significance: The current knowledge base suggests that CYP2D6 genetic variation has an appreciable impact on antipsychotic pharmacokinetics and the propensity for adverse drug reactions, particularly among children receiving risperidone treatment. However, several limitations with the current literature (e.g., sample sizes, study design, sample heterogeneity) should be addressed in future studies. Assuming that future studies support the link between CYP2D6 genetic variation and antipsychotic outcomes, we would anticipate an increase in the implementation of CYP2D6-guided antipsychotic drug selection and dose optimization in child and adolescent psychiatric services.

Association between the -2548G/A polymorphism of the leptin gene and antipsychotic-induced weight gain: Analysis of the CATIE sample and meta-analysis

BACKGROUND

Antipsychotics, especially most of the second-generation antipsychotics, have a high risk for metabolic syndrome and antipsychotic-induced weight gain (AIWG). A promoter variant of the leptin (LEP) gene, -2548G/A (rs7799039), has been associated with AIWG in several studies. The aim of this study was to evaluate this association in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) sample, followed by meta-analysis.

METHODS

We investigated the association between rs7799039 and AIWG in a sub-sample of European (N = 164) individuals from the CATIE study. Body mass index (BMI) change and weight gain (presence or absence) was analyzed using ANCOVA and logistic regression, respectively. For the meta-analysis, a literature search was conducted using MEDLINE, Embase, and PsycINFO up to October 2019. The pooled odds ratio was calculated for presence or absence of weight gain (≥7% weight change) using a random effects model.

RESULTS

We did not detect an association between rs7799039 and BMI change or weight gain (presence or absence) in the CATIE sample. As for the meta-analysis, we included 12 studies. No significant associations between the LEP rs7799039 polymorphism and AIWG were observed under the allelic genetic model (allele A vs. allele G) (OR = 1.10 [0.71, 1.70], p = .68). In the subgroup analyses of first-episode schizophrenia patients, a significant association between the A-allele and weight gain was observed, respectively (OR = 2.32 [1.41, 3.82], p = .0009).

CONCLUSIONS

The present meta-analysis showed no significant effect of rs7799039 on AIWG. However, this variant may influence AIWG in first-episode schizophrenia patients. Further investigation of a larger and more homogenous sample is required to elucidate the role of the LEP gene in AIWG.

DRD2/ANKK1 TaqI A1 polymorphism associates with overconsumption of unhealthy foods and biochemical abnormalities in a Mexican population

PURPOSE

The dopamine receptor 2/ankyrin repeat domain and content kinase 1 (DRD2/ANKK1) TaqIA polymorphism (rs1800497) has been associated with rewarding behaviors. This study aimed to investigate the association of DRD2/ANKK1 TaqIA polymorphism with the dietary intake, the intake frequency of food groups and biochemical profile in Mexican mestizo subjects.

METHODS

A cross-sectional/analytical study with 276 Mexican subjects was performed. Dietary intake was assessed with a 24-h recall and a food frequency questionnaire (FFQ). An allelic discrimination assay evaluated DRD2/ANKK1 TaqIA genotypes. Anthropometric and biochemical data were evaluated.

RESULTS

Genotype frequencies were A1A1 (18.48%), A1A2 (45.29%) and A2A2 (36.23%). TaqI A1 allele carriers had a higher intake of carbohydrates (p = 0.038), meats (p = 0.005), fried dishes (p = 0.039), and sugars (p = 0.009). Male TaqI A1 carriers consumed more carbohydrates (p = 0.009) and meats (p = 0.018) while females consumed fewer legumes (p = 0.005). TaqI A1 carriers had glucose (p = 0.037) and triglycerides (p = 0.011) abnormalities. TaqI A1 was associated with higher risk of consumption of unhealthy foods such as fried dishes (OR 3.79, 95% CI 1.53-9.35, p = 0.002) and meats (OR 2.31, 95% CI 1.32-4.05, p = 0.003), and lower healthy foods (OR 1.89, 95% CI 1.04-3.29, p = 0.038). TaqI A1 allele was associated with risk of abnormal glucose, triglycerides, and VLDL levels (OR 2.148, 95% CI 1.068-4.322, p = 0.036; OR 1.999, 95% CI 1.194-3.348, p = 0.011; OR 2.021, 95% CI 1.203-3.392, p = 0.007), respectively.

CONCLUSIONS

The presence of the TaqI A1 allele in Mexicans is a genetic risk factor for detrimental dietary quality that may predispose to metabolic disturbances.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

CYP2D6 genotype and adverse events to risperidone in children and adolescents

BACKGROUND

There are few and conflicting data on the role of cytochrome P450 2D6 (CYP2D6) polymorphisms in relation to risperidone adverse events (AEs) in children. This study assessed the association between CYP2D6 metabolizer status and risk for risperidone AEs in children.

METHODS

Children ≤18 years with at least 4 weeks of risperidone exposure were identified using BioVU, a de-identified DNA biobank linked to electronic health record data. The primary outcome of this study was AEs. After DNA sequencing, individuals were classified as CYP2D6 poor, intermediate, normal, or ultrarapid CYP2D6 metabolizers.

RESULTS

For analysis, the 257 individuals were grouped as poor/intermediate metabolizers (n = 33, 13%) and normal/ultrarapid metabolizers (n = 224, 87%). AEs were more common in poor/intermediate vs. normal/ultrarapid metabolizers (15/33, 46% vs. 61/224, 27%, P = 0.04). In multivariate analysis adjusting for age, sex, race, and initial dose, poor/intermediate metabolizers had increased AE risk (adjusted odds ratio 2.4, 95% confidence interval 1.1-5.1, P = 0.03).

CONCLUSION

Children with CYP2D6 poor or intermediate metabolizer phenotypes are at greater risk for risperidone AEs. Pre-prescription genotyping could identify this high-risk subset for an alternate therapy, risperidone dose reduction, and/or increased monitoring for AEs.

Association between serotonin 2C receptor gene (HTR2C) polymorphisms and psychopathological symptoms in children and adolescents

Serotonin 2C receptors (5HT2C) are involved in serotonin-driven dynamic equilibrium adjustments responsible for homeostatic stability in brain structures that modulate behavior and emotions. Single nucleotide polymorphisms (SNPs) from the serotonin 2C receptor gene (HTR2C) have been associated with several neurological and mental disorders, including abnormalities in cognitive and emotional processes. The aim of this study was to evaluate the association between the rs6318 SNP of the HTR2C gene and behavioral characteristics exhibited by children and adolescents based on the Child Behavior Checklist (CBCL/6-18) inventory. Eighty-five psychiatric outpatients between 8 and 18 years of age underwent genotyping of the rs6318 SNP. The CBCL/6-18 scale was administered to their caregivers. The chi-squared test was used to assess differences in the frequency of C and G alleles of the rs6318 SNP relative to the grouped CBCL/6-18 scores; significance level was 5%. The presence of the G allele of rs6318 was found to be associated with characteristics of aggressive behavior and social problems, and aggressive behavior was found to be associated with heterozygosis in females. These findings contribute to the identification of mental and behavioral phenotypes associated with gene expression.

Clinical Pharmacogenetics of Cytochrome P450-Associated Drugs in Children

Cytochrome P450 (CYP) enzymes are commonly involved in drug metabolism, and genetic variation in the genes encoding CYPs are associated with variable drug response. While genotype-guided therapy has been clinically implemented in adults, these associations are less well established for pediatric patients. In order to understand the frequency of pediatric exposures to drugs with known CYP interactions, we compiled all actionable drug-CYP interactions with a high level of evidence using Clinical Pharmacogenomic Implementation Consortium (CPIC) data and surveyed 10 years of electronic health records (EHR) data for the number of children exposed to CYP-associated drugs. Subsequently, we performed a focused literature review for drugs commonly used in pediatrics, defined as more than 5000 pediatric patients exposed in the decade-long EHR cohort. There were 48 drug-CYP interactions with a high level of evidence in the CPIC database. Of those, only 10 drugs were commonly used in children (ondansetron, oxycodone, codeine, omeprazole, lansoprazole, sertraline, amitriptyline, citalopram, escitalopram, and risperidone). For these drugs, reports of the drug-CYP interaction in cohorts including children were sparse. There are adequate data for implementation of genotype-guided therapy for children for three of the 10 commonly used drugs (codeine, omeprazole and lansoprazole). For the majority of commonly used drugs with known CYP interactions, more data are required to support pharmacogenomic implementation in children.

Corrigendum to "Pharmacogenetics of Risperidone and Cardiovascular Risk in Children and Adolescents"

[This corrects the article DOI: 10.1155/2016/5872423.].