Drug interactions
Biotin + Fosphenytoin
Severity: Minor
Biotin and Fosphenytoin: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Long-term phenytoin, the active form of fosphenytoin, has been associated with lower biotin levels, possibly due to reduced absorption and increased clearance. Clinical deficiency is uncommon.
What this interaction means in plain words
Biotin and Fosphenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Biotin belongs to Gastrointestinal Tract; Fosphenytoin belongs to Central Nervous System.
Why it happens
Anticonvulsants may impair intestinal biotin absorption and increase its catabolism; the mechanism is not fully established.
What to do
No routine action is required. Consider biotin assessment or supplementation if features of deficiency such as dermatitis or alopecia develop during long-term therapy.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Biotin
- Biotin + Levothyroxine Moderate
- Azithromycin + Biotin Minor
- Biotin + Carbamazepine Minor
- Biotin + Cefalexin Minor
- Biotin + Erythromycin base Minor
- Biotin + Erythromycin ethylsuccinate Minor
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Biotin with Fosphenytoin?
MediHelp rates the interaction as minor. Biotin and Fosphenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Long-term phenytoin, the active form of fosphenytoin, has been associated with lower biotin levels, possibly due to reduced absorption and increased clearance. Clinical deficiency is uncommon.
How serious is the interaction between Biotin and Fosphenytoin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine action is required. Consider biotin assessment or supplementation if features of deficiency such as dermatitis or alopecia develop during long-term therapy.
What other medicines interact with Biotin?
MediHelp also lists interactions of Biotin with, for example, Levothyroxine, Azithromycin, Carbamazepine. The full list is on the Biotin page.
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