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Introduction: Opioid use disorder is a cause for concern globally. This study aimed to optimize methadone dose adjustments using mixed modeling and machine learning. Methods: This retrospective study was conducted at Taichung Veterans General Hospital between January 1, 2019, and December 31, 2020. Overall, 40,530 daily dosing records and 1,508 urine opiate test results were collected from 96 patients with opioid use disorder. A two-stage approach was used to create a model of the optimized methadone dose. In Stage 1, mixed modeling was performed to analyze the association between methadone dose, age, sex, treatment duration, HIV positivity, referral source, urine opiate level, last methadone dose taken, treatment adherence, and likelihood of treatment discontinuation. In Stage 2, machine learning was performed to build a model for optimized methadone dose. Results: Likelihood of discontinuation was associated with reduced methadone doses (ß = 0.002, 95% CI = 0.000-0.081). Correlation analysis between the methadone dose determined by physicians and the optimized methadone dose showed a mean correlation coefficient of 0.995 ± 0.003, indicating that the difference between the methadone dose determined by physicians and that determined by the model was within the allowable range (p < 0.001). Conclusion: We developed a model for methadone dose adjustment in patients with opioid use disorders. By integrating urine opiate levels, treatment adherence, and likelihood of treatment discontinuation, the model could suggest automatic adjustment of the methadone dose, particularly when face-to-face encounters are impractical.
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PURPOSE: Paliperidone extended release (ER) is an oral psychotropic treatment formulated to release paliperidone at a controlled, gradually ascending rate. We evaluated the efficacy and safety of switching to paliperidone ER in Taiwanese patients with schizophrenia who were unresponsive or intolerant to previous antipsychotic therapy. PATIENTS AND METHODS: This was a 24-week, open-label, single-arm, multicenter, Phase IV trial. Based on consulting psychiatrists' judgment, patients were deemed eligible for the switch to paliperidone ER; the switch was achieved by cross-tapering, using a recommended starting dose of 6 mg. Eligibility considerations included lack of efficacy, tolerability, and/or adherence to previous oral antipsychotic medication. RESULTS: Of the 297 enrolled patients, 178 (59.5%) completed the study. The main reasons for discontinuation included insufficient efficacy (8.7%), patient decision (8.4%), and adverse events (AEs; 6.4%). Improvements in the: Positive and Negative Syndrome Scale total score and Clinical Global Impression-Severity score were observed only in patients treated at medical centers and not in those treated at psychiatric hospitals. The most common AEs were insomnia, headache, constipation, and extrapyramidal syndrome. One or more serious AEs were reported in 11 (3.7%) patients; none resulted in death. No significant changes in body weight, plasma glucose, or lipid levels were observed. CONCLUSION: Switching to paliperidone ER was effective and well tolerated for up to 24 weeks in patients with schizophrenia who were unresponsive or intolerant to previous antipsychotic therapy. The observed differences in treatment between psychiatric hospitals and medical centers with regard to dosage and titration of paliperidone ER warrant further investigation.