Progress on the Neuroscience-Based Nomenclature (NbN) for Psychotropic Medications

Current Findings and Potential Mechanisms of KarXT (Xanomeline-Trospium) in Schizophrenia Treatment

Standard schizophrenia treatment involves antipsychotic medications that target D2 dopamine receptors. However, these drugs have limitations in addressing all symptoms and can lead to adverse effects such as motor impairments, metabolic effects, sedation, sexual dysfunction, cognitive impairment, and tardive dyskinesia. Recently, KarXT has emerged as a novel drug for schizophrenia. KarXT combines xanomeline, a muscarinic receptor M1 and M4 agonist, with trospium, a nonselective antimuscarinic agent. Of note, xanomeline can readily cross blood-brain barrier (BBB) and, thus, enter into the brain, thereby stimulating muscarinic receptors (M1 and M4). By doing so, xanomeline has been shown to target negative symptoms and potentially improve positive symptoms. Trospium, on the other hand, is not able to cross BBB, thereby not affecting M1 and M4 receptors; instead, it acts as an antimuscarinic agent and, hence, diminishes peripheral activity of muscarinic receptors to minimize side effects probably stemming from xanomeline in other organs. Accordingly, ongoing clinical trials investigating KarXT's efficacy in schizophrenia have demonstrated positive outcomes, including significant improvements in the Positive and Negative Syndrome Scale (PANSS) total score and cognitive function compared with placebo. These findings emphasize the potential of KarXT as a promising treatment for schizophrenia, providing symptom relief while minimizing side effects associated with xanomeline monotherapy. Despite such promising evidence, further research is needed to confirm the efficacy, safety, and tolerability of KarXT in managing schizophrenia. This review article explores the current findings and potential mechanisms of KarXT in the treatment of schizophrenia.

Innovations in Psychopharmacology Education in U.S. Psychiatric Residency Programs

Medications available to treat psychiatric illnesses continue to increase, in conjunction with a shifting of outpatient psychiatric practice from psychotherapy toward medication management. To be successful in this climate, a psychiatrist needs to select the appropriate pharmacologic option(s) for their patient, drawing from old and new psychotropics while accounting for variables such as a patient's comorbid medical conditions and potential drug-drug interactions. In the absence of any national psychopharmacology training guidelines, these skills are taught to varying degrees in American psychiatric residency training programs. The past 20 years have seen an increase in innovations in the areas of psychopharmacology curricula topics, teaching strategies, and assessments of psychopharmacology knowledge and skills. Psychiatric training programs can benefit from and build on these innovations, ensuring that all physicians graduating from a psychiatric residency program meet psychopharmacology-based learning objectives and that their learning can be measured in a valid and reliable way.