Ramsey, Laura B.

Abstract Introduction Selective serotonin reuptake inhibitors (SSRIs) and, to a lesser extent, serotonin‐norepinephrine reuptake inhibitors (SNRIs) are the cornerstone of pharmacotherapy for children and adolescents with anxiety and depressive disorders. These medications alleviate symptoms and restore function for many youths; however, they are associated with a distinct adverse effect profile, and their tolerability may complicate treatment or lead to discontinuation. Yet, SSRI/SNRI tolerability has received limited attention in the pediatric literature. Methods This review examines the early‐ (e.g., activation, gastrointestinal symptoms, sedation) and late‐emerging (e.g., weight gain) adverse effects of SSRIs and some SNRIs in pediatric patients. Results We provide a framework for discussing SSRI/SNRI tolerability with patients and their families and describe the pharmacologic basis, course, and predictors of adverse events in youth. Strategies to address specific tolerability concerns are presented. For selected adverse events, using posterior simulation of mean differences over time, we describe their course based on Physical Symptom Checklist measures in a prospective, randomized trial of anxious youth aged 7–17 years who were treated with sertraline ( n = 139) or placebo ( n = 76) for 12 weeks in the Child/Adolescent Anxiety Multimodal Study (CAMS). Main Results In CAMS, the relative severity/burden of total physical symptoms ( p < 0.001), insomnia ( p = 0.001), restlessness ( p < 0.001), nausea ( p = 0.002), abdominal pain ( p < 0.001), and dry mouth ( p = 0.024) decreased from baseline over 12 weeks of sertraline treatment, raising the possibility that these symptoms are transient. No significant changes were observed for sweating ( p = 0.103), constipation ( p = 0.241), or diarrhea ( p = 0.489). Finally, we review the antidepressant withdrawal syndrome in children and adolescents and provide guidance for SSRI discontinuation, using pediatric pharmacokinetic models of escitalopram and sertraline—two of the most used SSRIs in youth. Conclusion SSRI/SNRIs are associated with both early‐emerging (often transient) and late‐emerging adverse effects in youth. Pharmacokinetically‐informed appraoches may address some adverse effects and inform SSRI/SNRI discontinuation strategies.

AimsHigh‐dose methotrexate (HDMTX) is an essential part of the treatment of several adult and paediatric malignancies. Despite meticulous supportive care during HDMTX administration, severe toxicities, including acute kidney injury (AKI), may occur contributing to patient morbidity. Population pharmacokinetics provide a powerful tool to predict time to clear HDMTX and adjust subsequent doses. We sought to develop and validate pharmacokinetic models for HDMTX in adults with diverse malignancies and to relate systemic exposure with the occurrence of severe toxicity.MethodsAnonymized, de‐identified data were provided from 101 US oncology practices that participate in the Guardian Research Network, a non‐profit clinical research consortium. Modelled variables included clinical, laboratory, demographic and pharmacological data. Population pharmacokinetic analysis was performed by means of nonlinear mixed effects modelling using MonolixSuite.ResultsA total of 693 HDMTX courses from 243 adults were analysed, of which 62 courses (8.8%) were associated with stage 2/3 acute kidney injury (43 stage 2, 19 stage 3). A three‐compartment model adequately fitted the data. Time‐dependent serum creatinine, baseline serum albumin and allometrically scaled bodyweight were clinically significant covariates related to methotrexate clearance. External evaluation confirmed a satisfactory predictive performance of the model in adults receiving HDMTX. Dose‐normalized methotrexate concentration at 24 and 48 hours correlated with AKI incidence.ConclusionWe developed a population pharmacometric model that considers weight, albumin and time‐dependent creatinine that can be used to guide supportive care in adult patients with delayed HDMTX elimination.