Phenytoin: molecular mechanisms & dependencies

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

Human evidence only

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

Where it participates (unsigned role)

The carbamazepine/phenytoin group had higher urinary 3-HIA, but only one child in that group had low urinary biotin.
Carbamazepine → Human urinary 3-hydroxyisovaleric acid excretion source_derived_draftungraded
Experimental context and source evidence
availability_state
biomarker_context Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/biotin-research/9523856.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136", "start_char": 0, "end_char": 1876, "text_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136"}
experimental_model
Observational urine comparison: 7 children receiving carbamazepine/phenytoin, 6 phenobarbital, 16 controls
exposure
Long-term anticonvulsant treatment
limitations
Untimed urine, small nonrandomized groups and discordant markers limit diagnosis; faster turnover is not a universal deficiency diagnosis.
nutrient_topic
Biotin research collection; topical membership is not evidence of a direct dietary effect. · Biotin
organism
Homo sapiens
plain_language
Different biotin-status markers did not give the same answer in these children.
primary_references
[b7-p9523856] Disturbances in biotin metabolism in children undergoing long-term anticonvulsant therapy. (1998). https://pubmed.ncbi.nlm.nih.gov/9523856/ DOI: 10.1097/00005176-199803000-00002
tissue_or_cell_type
Urine
trigger_kind
biomarker_context Imported condition classification; unverified.
Biotin: carboxylases, recycling, deficiency and nutrient interactions (2026-09-17) · lines 312–323
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Observational urine comparison: 7 children receiving carbamazepine/phenytoin, 6 phenobarbital, 16 controls · source_derived_draft · unverified_draft
### b7-drug-3hia The carbamazepine/phenytoin group had higher urinary 3-HIA, but only one child in that group had low urinary biotin. Condition category: biomarker_context nutrient_topic: Biotin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Different biotin-status markers did not give the same answer in these children. organism: Homo sapiens tissue_or_cell_type: Urine experimental_model: Observational urine comparison: 7 children receiving carbamazepine/phenytoin, 6 phenobarbital, 16 controls limitations: Untimed urine, small nonrandomized groups and discordant markers limit diagnosis; faster turnover is not a universal deficiency diagnosis. exposure: Long-term anticonvulsant treatment evidence_span: {"source_cache": "artifacts/biotin-research/9523856.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136", "start_char": 0, "end_char": 1876, "text_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136"} [b7-p9523856] Disturbances in biotin metabolism in children undergoing long-term anticonvulsant therapy. (1998). https://pubmed.ncbi.nlm.nih.gov/9523856/ DOI: 10.1097/00005176-199803000-00002
Complete structured claim and evidence
Urinary bisnorbiotin was higher in both carbamazepine/phenytoin-treated and phenobarbital-treated children than in controls.
Carbamazepine → Human urinary bisnorbiotin excretion source_derived_draftungraded
Experimental context and source evidence
availability_state
biomarker_context Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/biotin-research/9523856.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136", "start_char": 0, "end_char": 1876, "text_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136"}
experimental_model
Observational urine comparison: 7 children receiving carbamazepine/phenytoin, 6 phenobarbital, 16 controls
exposure
Long-term anticonvulsant treatment
limitations
Untimed urine, small nonrandomized groups and discordant markers limit diagnosis; faster turnover is not a universal deficiency diagnosis.
nutrient_topic
Biotin research collection; topical membership is not evidence of a direct dietary effect. · Biotin
organism
Homo sapiens
plain_language
Some anticonvulsant-treated children excreted more of a biotin breakdown product.
primary_references
[b7-p9523856] Disturbances in biotin metabolism in children undergoing long-term anticonvulsant therapy. (1998). https://pubmed.ncbi.nlm.nih.gov/9523856/ DOI: 10.1097/00005176-199803000-00002
tissue_or_cell_type
Urine
trigger_kind
biomarker_context Imported condition classification; unverified.
Biotin: carboxylases, recycling, deficiency and nutrient interactions (2026-09-17) · lines 299–310
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Observational urine comparison: 7 children receiving carbamazepine/phenytoin, 6 phenobarbital, 16 controls · source_derived_draft · unverified_draft
### b7-drug-bisnorbiotin Urinary bisnorbiotin was higher in both carbamazepine/phenytoin-treated and phenobarbital-treated children than in controls. Condition category: biomarker_context nutrient_topic: Biotin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Some anticonvulsant-treated children excreted more of a biotin breakdown product. organism: Homo sapiens tissue_or_cell_type: Urine experimental_model: Observational urine comparison: 7 children receiving carbamazepine/phenytoin, 6 phenobarbital, 16 controls limitations: Untimed urine, small nonrandomized groups and discordant markers limit diagnosis; faster turnover is not a universal deficiency diagnosis. exposure: Long-term anticonvulsant treatment evidence_span: {"source_cache": "artifacts/biotin-research/9523856.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136", "start_char": 0, "end_char": 1876, "text_sha256": "a337d853fbf3d26e053dfd6d17b2e1729c993a0501563d0524ebbee7b44d5136"} [b7-p9523856] Disturbances in biotin metabolism in children undergoing long-term anticonvulsant therapy. (1998). https://pubmed.ncbi.nlm.nih.gov/9523856/ DOI: 10.1097/00005176-199803000-00002
Complete structured claim and evidence

The events it takes part in

A mechanism often involves more than two components. These are the full events, with every participant and its role.

Situations it appears in

Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

Open hypotheses

Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.

This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

Phenytoin