Absorption, Metabolism, and Excretion of [ <sup>14</sup> C]Viramidine in Humans
Bibliographic record
Abstract
Absorption, metabolism, and excretion of [14C]viramidine, a prodrug of ribavirin, were studied in humans following a single oral dose (600 mg). Viramidine was rapidly absorbed, with a time to maximum concentration of the drug in plasma of 1.5 h. Viramidine and ribavirin accounted for only 4.3% and 42% of plasma area under the concentration-time curve (AUC) for radioactivity, respectively, indicating extensive conversion of viramidine to ribavirin, followed by further metabolism of ribavirin. The drug was largely trapped in red blood cells (RBC), with an RBC-to-plasma radioactivity AUC0-infinity ratio of 108. Excretion of total radioactivity in urine and feces accounted for 50.8% and 26.1% of the dose, respectively. The metabolic profile in urine (0 to 24 h) indicated that viramidine was excreted primarily as triazole carboxamide (TCONH2), triazole carboxylic acid nucleoside (TCOOH), and ribavirin with a small amount of unchanged viramidine, which each accounted for 64.1%, 17.0%, 15.7%, and 3.2% of urinary radioactivity, respectively. The amounts of unchanged viramidine (3.4% of dose) and ribavirin (10% of dose) in urine were small after oral administration of viramidine.
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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 | 0.000 | 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".