Impact of Once- Versus Twice-Daily Perphenazine Dosing on Clinical Outcomes
Bibliographic record
Abstract
OBJECTIVE: The objective of this study was to evaluate the impact of once- versus twice-daily dosing of perphenazine, which has a plasma half-life of 8-12 hours, on clinical outcomes in patients with schizophrenia. METHOD: Data from phase 1 of the Clinical Antipsychotic Trial of Intervention Effectiveness (CATIE) conducted between January 2001 and December 2004 were used in this post hoc analysis. Patients with schizophrenia (DSM-IV) randomly allocated to treatment with perphenazine were also randomly assigned to once-daily (N = 133) or twice-daily (N = 124) dosing and followed over 18 months. Discontinuation rate and time to discontinuation were used as primary outcomes to compare the 2 groups. The following clinical outcomes were analyzed as secondary measures: efficacy-Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity scale, Calgary Depression Scale for Schizophrenia, and Drug Attitude Inventory and safety/tolerability-Abnormal Involuntary Movement Scale, Barnes Akathisia Rating Scale, Simpson-Angus Scale, and body weight. Data on treatment-emergent adverse events, concomitant psychotropic medications, and medication adherence (pill count and clinician rating scale) were also analyzed for each group. RESULTS: No significant differences were found in any outcome measures between the once-daily and twice-daily dosing groups, which remained the same when using the mean dose of perphenazine as a covariate. CONCLUSIONS: Perphenazine is routinely administered in a divided dosage regimen because of its relatively short plasma half-life. However, the present findings challenge such a strategy, suggesting that once-daily represents a viable treatment option. Results are discussed in the context of more recent evidence that challenges the need for high and continuous dopamine D2 receptor blockade to sustain antipsychotic response. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00014001.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.011 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".