CYP2D6 Genotype and Pharmacovigilance Impact on Autism Spectrum Disorder: A Naturalistic Study with Extreme Phenotype Analysis.

The long-term use of psychopharmacology medications in autism spectrum disorder (ASD) hitherto remains controversial due to a lack of evidence about safety and tolerability. In this regard, genotyping the metabolizing enzyme cytochrome P450 (CYP) 2D6, especially its extreme phenotypes, could help to prevent drug-related adverse reactions or adverse events (AEs). There are several medications warranting CYP2D6 screening that are consumed by people with ASD, such as risperidone and aripiprazole to name a few. A naturalistic observational study was carried out in participants with ASD to analyze the influence of the CYP2D6 phenotype in drug tolerability using a local pharmacovigilance system created for this study. In this case, AEs were identified from participants' electronic health records (EHRs) and paper registries. Other variables were collected: socio-demographic information, comorbidities, and psychopharmacology prescriptions (polypharmacy defined as ≥4 simultaneous prescriptions) and doses. The genetic analysis included allelic discrimination (CYP2D6*1, *2, *3, *4, *5, *6, *10, *17, and *41) and copy number variations. All of these were used to determine theoretical phenotypes of the metabolic profiles: poor (PM); intermediate (IM); normal (NM); and ultra-rapid (UM). Sex differences were analyzed. A total of 71 participants (30 ± 10 years old, 82% male, 45% CYP2D6 NM phenotype (32 participants)) with a median of 3 (IQR 2-4) comorbidities per person, mainly urinary incontinence (32%) and constipation (22%), were included. CYP2D6 UM showed the highest rate of polypharmacy, whilst, IM participants had the highest rates of neurological and psychiatric AEs, even worse if a CYP2D6 inhibitor drug was prescribed simultaneously. CYP2D6 pharmacogenomics and the monitoring of new antipsychotic prescriptions may make a difference in medication safety in adults with ASD. Particularly in those with psychopharmacology polymedication, it can help with AE avoidance and understanding.

The challenge of detecting adverse events in adults with autism spectrum disorder who have intellectual disability.

Adults with autism spectrum disorder (ASD) and associated intellectual disability (ID) take a high number of different psychotropic drugs simultaneously. Nowadays, little is known about this multidrug pattern efficacy and safety. The present study has endeavored to fill this gap creating a local pharmacovigilance system. A 36-month, retrospective and prospective, observational, and multicenter pharmacovigilance study was carried out in adults with ASD and ID (n = 83). Information regarding ongoing medications (polypharmacy: taking simultaneously >4 drugs; safety profile: adverse events' number, adverse drug reactions' number, and affected system; and observed-to-expected [O/E] ratio using the summary of product characteristics), and current diagnoses were recorded. A median of four ongoing medications per participant was registered, half of the sample was under polypharmacy regimen. Regarding all ongoing medications, 50% were antipsychotic drugs, and 47% of participants had >1 antipsychotic prescribed. In contrast, only 64 adverse events were identified from electronic health records, mostly due to risperidone. Half of them were related either to nervous or metabolic systems, and almost a third were not previously described in the corresponding drug summary of products characteristics. Extrapyramidalism, gynecomastia, hypercholesterolemia, and urinary retention were some AEs that occurred more frequently than expected (O/E ratio > 6 times) according to our data. The highest O/E ratio scores (>120 times) were for hypercholesterolemia and rhabdomyolysis caused by valproic acid. According to the number of adverse events and adverse drug reactions reported in electronic health records locally and nationally by clinicians, we need to increase awareness about medications safety. LAY SUMMARY: A 36-month study in adults with autism, ID, and polypharmacy (>4 drugs) was done to investigate drug safety on everyone. A median of four medications per person was registered, half were antipsychotic drugs, and 47% of participants had >1 antipsychotic medication simultaneously. Only 64 adverse events were identified from electronic health records, mostly due to risperidone. Half of them were related to nervous or metabolic systems and a third were not previously described in the drug information sheet.

Multimorbidity and psychotropic polypharmacy among participants with autism spectrum disorder with intellectual disability.

Nowadays, adults with autism spectrum disorder (ASD) experience several comorbidities whose treatment implies a wide range of psychotropic prescriptions. This study aimed to evaluate medication-related safety, drug-drug interactions, and psychotropics prescription trends. We conducted an observational and multicentric pharmacovigilance study in subjects with ASD and Intellectual disability (ID, n = 83). Clinical information (diagnoses, ongoing medications, comorbidities [multimorbidity ≥ 4 chronic health conditions]) and psychotropic prescriptions (polypharmacy ≥ 4 chronic drugs, daily drug doses, co-prescription) were registered. Ethical approval for this study was obtained. Participants (30±10 years old, 86% men, BMI 27±6 kg/m2) displayed 37% multimorbidity (mean of 3, IQR 2-4), and 57% polypharmacy (13% out of dose recommended range). Most drugs prescribed were psychotropic risperidone which is related to nervous system comorbidities (18% epilepsy, 16% insomnia, and 14% psychotic agitations). Risperidone and quetiapine were co-prescribed in 60% of the cases without any monitoring adverse event routine. The rates of multimorbidity and polypharmacy, among our young adults with ASD and ID, are concerning. Data suggest the need to develop a pharmacovigilance monitoring system to evaluate prescription accuracy, long-term safety of ongoing medications, and the fixed doses in this autistic population with associated ID.