Drug interactions
Phenytoin + Silodosin
Severity: Minor
Phenytoin and Silodosin: 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
Phenytoin induces CYP3A4 and can reduce silodosin concentrations, potentially weakening its effect on urinary symptoms. Clinical consequences are mainly reduced efficacy.
What this interaction means in plain words
Phenytoin and Silodosin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Phenytoin belongs to Central Nervous System; Silodosin belongs to Genitourinary.
Why it happens
Phenytoin induces CYP3A4 and possibly P-glycoprotein, increasing silodosin clearance.
What to do
Monitor symptom response and consider an alternative agent if efficacy is lost.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Phenytoin and Silodosin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Silodosin
- Atazanavir + Silodosin Contraindicated
- Conivaptan + Silodosin Contraindicated
- Darunavir + Silodosin Contraindicated
- Fosamprenavir + Silodosin Contraindicated
- Indinavir + Silodosin Contraindicated
- Itraconazole + Silodosin Contraindicated
Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Phenytoin with Silodosin?
MediHelp rates the interaction as minor. Phenytoin and Silodosin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Phenytoin induces CYP3A4 and can reduce silodosin concentrations, potentially weakening its effect on urinary symptoms. Clinical consequences are mainly reduced efficacy.
How serious is the interaction between Phenytoin and Silodosin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor symptom response and consider an alternative agent if efficacy is lost.
What other medicines interact with Silodosin?
MediHelp also lists interactions of Silodosin with, for example, Atazanavir, Conivaptan, Darunavir. The full list is on the Silodosin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
