Long‐Term Migraine Prevention With Topiramate: Open‐Label Extension of Pivotal Trials
Bibliographic record
Abstract
OBJECTIVE: To demonstrate that topiramate is an effective and generally well-tolerated migraine preventive therapy when used for up to 14 months. BACKGROUND: Topiramate 100 and 200 mg/d significantly reduced mean monthly migraine frequency during 2 large, 26-week, randomized, placebo-controlled trials. Only a small number of clinical trials have examined the long-term (> or =1 year) effectiveness and safety of migraine preventive therapies. METHODS: Five hundred sixty-seven patients with an established history of migraine with or without aura were enrolled in this 8-month, open-label extension of 2 large (49 US and 52 US and Canadian medical centers), randomized, double-blind, placebo-controlled, parallel group, 26-week trials of identical design. To be eligible for the open-label extension, patients were required to have either completed the double-blind phase of the 2 pivotal migraine prevention trials or withdrew after 4 weeks due to lack of efficacy. All eligible patients, regardless of type or dose of study medication (topiramate or placebo) received in the double-blind phase, were titrated to a clinically effective dose of open-label topiramate based on physician judgment of patient response. Efficacy of topiramate was measured as the change in mean monthly migraine frequency. RESULTS: The mean topiramate dose during the open-label extension phase was 124.7 mg/d and 150.3 mg/d for patients on placebo (n = 159) or topiramate (n = 408), respectively, during the double-blind phase (N = 567, 91% female, mean age 39.4 years). Patients on topiramate for up to 14 months had 2.2 +/- 2.4 (mean +/- SD) migraines per month after completion of the open-label extension phase (3.4 +/- 2.6 at double-blind endpoint). Patients on topiramate during the open-label extension phase only (placebo during the double-blind phase) had 3.0 +/- 2.9 migraines per month at open-label extension endpoint (4.9 +/- 3.0 migraines per month at double-blind endpoint). Discontinuation rates due to adverse events during the double-blind phase were 22.2% for patients on topiramate and 11.0% for patients on placebo. Discontinuation rates due to adverse events during the open-label extension phase were 8.6% for those patients who had already received topiramate during the double-blind phase and 20.9% for those patients who had previously received placebo. CONCLUSIONS: Patients receiving topiramate experienced a sustained reduction in migraine frequency for up to 14 months. The effectiveness and safety of topiramate was consistent with that observed during 2 26-week pivotal trials.
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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 | 0.014 | 0.010 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.003 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.004 | 0.004 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
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".