Quetiapine Extended-Release Versus Immediate-Release Formulation
Bibliographic record
Abstract
OBJECTIVE: The pharmacokinetic and pharmacodynamic profile of the immediate-release (IR) formulation of quetiapine is characterized by a rapid peak in plasma level and striatal dopamine D(2) receptor occupancy, followed by a rapid decrease to baseline levels, necessitating the use of twice-daily dosing. An extended-release (XR) formulation of quetiapine is currently being developed to achieve similar efficacy using a once-daily dosing regimen. We compared the central D(2) receptor binding between the IR and XR formulations. METHOD: In this open-label, crossover positron emission tomography study using [(11)C]-raclopride, we compared the central D(2) receptor binding potential at expected peak and trough plasma levels using equivalent daily doses of the IR and XR formulations (300, 600, and 800 mg/day) in 12 subjects. Data were collected from April 2002 to May 2003. RESULTS: The mean plasma level of quetiapine at trough was significantly lower than that at peak for all dose groups of both formulations except for IR 300 and 800 mg (all p values < .05), while the mean plasma level did not differ significantly between formulations at trough and peak. The mean occupancy at peak was significantly higher than that at trough for all dose groups other than IR 800 mg/day (all p values < .05) and did not differ significantly between formulations at trough and peak. CONCLUSION: Once-daily dosing of the XR formulation gives peak and trough plasma levels and central D(2) receptor occupancy comparable to twice-daily dosing of the IR formulation. These data should be considered while determining equivalent doses, as well as switching strategies.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".